Home

EyeLink Data Viewer User's Manual

1. Figure 8 8 Using the Trial Variable Manager Changing Variable Labels 8 3 3 Managing Reaction time definitions One of the important features of the EyeLink Data Viewer is the capability of creating condition based or trial based reaction time definitions For example for the current example we may want to calculate reaction times for target absent trials terminated by pressing button 3 and target present trials terminated by pressing button 4 separately Such functionality can be achieved in several ways In the first approach simple messages can be added in the EDF file to automate a set of condition based reaction time definitions see section 7 4 1 The C code to record such messages could be eyemsg printf V_ RT BUTTON SYNCTIME 3 1 PRESENCE Absent eyemso Printi V RI BUTTON SYNCTIME 4 1 PRESENCE Present To enable the correct loading of these condition based reaction time definitions the above messages must be sent to the EDF file prior to the first trial start message e g TRIALID but adter the TRIAL VAR LABEL message Alternatively a trial specific RT message can be recorded for each individual trial Thus for all target absent trials a message like eyemsg printf V V CRT BUTTON SYNCTIME 3 1 can be added to the experiment source code whereas for all target present trials a message like eyemsg printf V V CRT BUTTON SYNCTIME 4 1 can be added To enable the proper functioning of the trial based rea
2. Buck l Type RECTANGLE Lefi 51 0 Top 23 0 Right 146 0 Bottari 62 0 S50 Figure 5 10 Sample Text Display Overlaid with Interest Areas Area of the interest area in pixels Color To achieve better visibility the color of the currently selected area interest can be changed by clicking on the color toolbox Time EDF file Time when the interest area was created with the V IAREA command during recording If the interest area was created during the viewing session manually or from interest area template file the time value will be 1 and this attribute will not be visible from the property table The interest area time was useful only when interest periods are created and used 1 e to filter interest areas based on the current selected EyeLink Data Viewer 2002 2008 SR Research Ltd 35 _ interest period Number Fixations Total number of fixations within the interest area Fixation Percentage of total fixations in a trial falling within the current interest area Dwell Time Total time in milliseconds spent on the current interest area Dwell Time Percentage of trial dwell time spent on the current interest area Sequence Run Count Number of times the interest area was entered and left 1 e run Note The coordinate information Left Top Right and Bottom 1s available for the rectangular and elliptic interest areas only 5 8 1 Manually Creating Interes
3. General Details Start Time Message Text Start Time Ottset End Time Button Number any C Released End Time Offset l Pressed Figure 6 11 Interest Period Editor Details Tab Similar to the reaction time definition the layout of the Details tab depends on the type of the end event the user selected in the General Tab EyeLink Data Viewer 2002 2008 SR Research Ltd Pi elarentinbtcSgyiitesia Port oe on so vasta placo but pes Then there was 52 oe Button Event This will treat a particular button press release as the interest period end event In the Start Time Message Text edit box enter the message string case sensitive DO NOT include quotes for text strings Select the intended button ID from the Button Number combo box and choose the desired button state button pressed or released The user can also specify a time offset 0 or a positive number in milliseconds for the start time and end time so that the interest period does not start or end right on the time of message and or button event Message Event This will treat the first occurrence of a matching message as the end event for the interest period Enter the desire message strings for both the Start Time and End Time Message Text edit boxes case sensitive with no quotes for text strings The user can also set a time offset 0 or a positive number in milliseconds for the start time and end time Ple
4. PEUS Custorn mage Mame Mapping Sac _blur jp a 5 8 9 Deleting Interest Area Templates Interest area templates can be deleted from IA template list In the Treeview panel of the Inspector window locate the Interest Area Templates folder where all of the interest area templates are loaded Select the target interest area template from the list click the right mouse button and select Delete If the deleted interest area template is being used by a trial the Interest Area Set property of that trial will be set to Empty Interest Area Set er Inspector l TE Data MA Preferences Untitled evs Import Message List HO test3 jas EO test4 ias Ho Empty Interest Area Set 5 8 10 Selecting Interest Areas To select an interest area place the mouse cursor over the interest area and click the left mouse button The interest area is highlighted after selection To select more than one EyeLink Data Viewer 2002 2008 SR Research Ltd 40 interest area hold the CTRL key down and select the target area until all desired interest areas are selected If all interest areas in the trial are to be selected simply click the Select All Visible Item button 2 on the toolbar or click the right mouse button and select Select All Note If there are eye movement events within the interest area to be selected clicking on the interest area will likely select the eye movement events instead To make a m
5. button from the menu bar of the trial spatial overlay view window The Data Viewer also allows the user to create a screen capture of the spatial overlay view or the temporal graph view of a given trial by clicking on the Save Trial View as Image button fe see Figure 8 4 so Trial iew HD_RCN Trial 1 Oo x Z jejege E Save Trial view as Image 468 132 156 oi Save x Look in Qvisualgseach i H El E aaa Trial0 Save Files of type Supported image Files M Cancel Figure 8 4 Creating a Screen Capture of the Spatial Overlay View or the Temporal Graph View of a Trial 8 3 2 2 Loading Trial Interest Area Set Similarly the V IAREA FILE command loads a specified interest area set file and segments the display according to the interest areas listed in the file If the IAREA command was not initially recorded in the data file the trial interest areas can be created in three ways The first one is to load an interest area file or interest area template file by clicking the Import Area of Interest File ll button In the Load dialog select the desired interest area set file The second approach is to allow the viewer to create interest areas if a trial bitmap has already been loaded into the Viewer by clicking the Auto EyeLink Data Viewer 2002 2008 SR Research Ltd 112 Segment Image to Interest Area button AS This approach 1s applicable for those displays in which the indiv
6. Figure 8 5 Using the Trial Variable Manager Creating a New Variable To demonstrate the functionality of the Trial Variable Manager here we remove the PRACTICE variable and create a similar variable called PracticeTrial To remove a variable simply select it and click the Delete Selected Variable button To create a new variable click the New Variable button A new row titled label default value is added to the variable list To edit the label of the new variable select it and type in EyeLink Data Viewer 2002 2008 SR Research Ltd 113 PracticeTrial in Label edit box and press the enter key To assign a default value for that variable type in Test and press the enter key see Figure 8 6 Now in the Trial Variable Value Editor dialog we will see that for all trials the values for the new variable PracticeTrial are set as Test see Figure 8 6 We know that Trial 1 18 and Trial 115 132 were practice trials To change the values for those trials double click on the current cell value type in Practice and press the Enter key to register the change a Trial Yariable alue Editor DRCN Practice DRCN Trial 2 Practice DRCN fma sooo01 High dscrimina ingle Feature Absent D_RCN DRCN Tria 5000100 High dscriina Single feature Absent actce HD RCH Trial 6 6110102 High_discrimina Single _Feature Present z ractice DRCN Mraz 120101 igh discrimina D_RCN DRCN Trial
7. X Resolution Angular resolution at current gaze position in screen pixels Y Resolution per visual degree 4 1 1 3 1 Hiding a Trial To hide a trial from the output reports 1 Click the trial to hide in the top panel of the data tab 2 In the bottom panel of the data tab which contains properties for the trial find the entry Report Hidden and change the current setting 4 1 1 3 2 Deleting a Trial To delete a trial from the Data Viewer simply place the mouse over that trial node click the right mouse button and select Delete The trial is permanently removed from the data viewing session and all other trial indexes are updated accordingly 4 1 1 4 Interest Area Templates An interest area template is a AS file that contains a set of interest areas If the same interest areas are used for several trials instead of repeating the procedure of creating interest areas for each individual trial an interest area template can be loaded to supply segmentation information for those trials efficiently The property panel lists the following summary statistics for an interest area template Those fields that are editable in the viewer are marked with an asterisk EyeLink Data Viewer 2002 2008 SR Research Ltd 12 Label of the custom interest area set IA Count Total number of interest areas defined in the trial IsCustom Whether the current set of interest areas 1s user defined true or an interest area template false Ima
8. Label of the fixation The eye to which the current fixation event is associated Start Time Trial time when the fixation starts Please note that if an interest period filter 1s applied the duration start time and end time of the fixations that overlap with the start or end of the interest period will be adjusted accordingly Trial time when the fixation ends Duration in milliseconds of the fixation Avg Y Position the current fixation and the previous next fixation fixation and the previous next fixation Direction Direction LEFT RIGHT UP or DOWN relative to the current fixation in which the previous next fixation 1s located Whether the current fixation is the reaction time end event see section 6 3 1 for reaction time definition output analysis Whether the fixation has been shifted manually To achieve better visibility the color of the currently selected fixation can be changed by clicking on the color toolbox Note System time refers to the timestamp in milliseconds since the EyeLink tracker was activated whereas the trial time refers to the time since the trial started The default trial start time is the start of the trial recording 1 e START message If reaction time definitions are applied the trial start time is reset at the start event of the RT definition e g SYNCTIME message A negative trial time means that the event or message occurred before the tria
9. The temporal graph can be zoomed in and out To zoom into an area of the temporal graph 1 Hold the Shift key down or press the button 2 Position the mouse on the temporal graph at the location of the upper left hand corner of the area you wish to zoom into 3 Press the mouse button and drag the mouse to the lower right hand corner of the area you wish to zoom into 4 Release the mouse button 5 Release the Shift key The graph will be magnified so that the area you selected fills the Trial View Window Tip Holding the CTRL key while defining the zoom in region will change to time period to be magnified only the spatial range displayed is not altered To zoom out the graph press the X button The temporal graph will be zoomed out by a factor of 2 4 5 Animation View The Animation View see Figure 4 6 is selected by pressing the button in the Trial View window This view plays back the gaze position superimposed on the background image that the participant was looking at while the data was being recorded with a concurrent time code displaying the time from the start of trial recording Several controls are available for the animation view The user can start stop or pause the playback by clicking the appropriate button The speed of playback can also be adjusted the user modifies the speed value and then press the Enter key to register the change A trackbar control displays the progress of the playback and
10. is on and its duration is less than the specified duration threshold Saccade Amplitude Threshold Sets the minimum size of a saccade to be displayed in the viewing session All saccades will be displayed with an amplitude threshold set to 0 0 Display Blink Saccades Shows flanking saccades of a blink Hide Fixations Beyond Display Bounds Whether or not to hide the fixations falling beyond the display boundaries Show Interest Areas Pre Interest Period If interest periods are defined whether or not to display interest area timed before the start of a selected interest period If no interest periods are defined the interest areas are displayed anyway Show Interest Areas Post Interest Period If interest periods are defined whether or EyeLink Data Viewer 2002 2008 SR Research Ltd 133 not to display interest area timed after the end of a selected interest period If no interest periods are defined the interest areas are displayed anyway Hide Eye Events Only If checked filters out eye events fixations saccades and blinks falling outside of the RT definition If unchecked filter out all events including buttons events and messages Hide Spanned Events For the RT filter whether or not to hide an event e g fixation or saccade that overlaps with the start event or end event of the RT definition Trimmed Spanned Fixation Duration If an interest period reaction time filter is applied the duration of the fi
11. 4 Animation Right Eye x Sample Trace Color Y Sample Trace Color x velocity Trace Color fr Velocity Trace Color hx Accelleration Trac I Accelleration Trac Pupil Sample Trace C Lett Eye i Sample Trace Color Y Sample Trace Color x Velocty Trace Color y velocty Trace Color ix Acceleration Trac D fe Acceleration Trac Pupil Sample Trace C x Position Trace Color J Y Position Trace Color x Velocity Trace Color EyeLink Data Viewer Left Eye Right Eye X Sample Trace Color Y Sample Trace Color X Velocity Trace Color Y Velocity Trace Color X Acceleration Trace Color Y Acceleration Trace Color and Pupil Sample Trace Color Set the colors to be used to show the horizontal and vertical position velocity and acceleration traces of the eye samples The pupil sample traces of both eyes are also displayed The default settings can be changed by clicking the corresponding cell and choosing a color from the palette or entering the value in RGB or HSB scales Target 1 Target 2 Key Token word to indicate the target ID This field is set to blank by default so that various token words can be used If two targets are involved and 1f the order of the two targets is important set this field to the token string used in the EDF file X Position Trace Color Y Position Trace Color X Velocity Trace Color Y Velocity Trace Color X Acceleration Trace Color Y Acc
12. 590 234 1 0 Note The user can use any token word to indicate the target ID The key property of the temporal graph preference settings is set to blank by default so that various token words can be used If two targets are involved and if the order of the two targets is important set that field to the token strings used in the target position command string 7 4 Reaction Time Definitions To obtain an accurate reaction time RT measure the EyeLink Data Viewer relies on a set of reaction time definitions to parse the start and end events for RT calculation The reaction time definition command messages inform the Viewer of the RT start message the type of RT end events fixation saccade message or button the parameters of the end event as well as the conditions to which the RT definition is applied Reaction time definition commands can be provided in two ways The user can employ a pre trial condition based command messages to specify a RT definition for each of the experimental condition All pre trial reaction time commands start with the V_RT token and are followed by a one word subcommand indicating the type of RT end event BUTTON MESSAGE FIXATION or SACCADE Alternatively the user can supply a custom reaction time definition specifically for each trial All custom trial specific reaction time commands start with the V V_CRT token and are followed by a one word subcommand Important When an EyeLink Data File is loaded
13. Display Width Screen resolution width and height in pixels of the recording Display Height displays By default this sets the trial view window resolution to the value specified by display Coordinates messages If you want to change the screen resolution make sure that you first close the Trial View Window first change the Display Width and Display Height values and then open another trial view window EyeLink Data Viewer 2002 2008 SR Research Ltd 10 4 1 1 2 1 Deleting a group of trials To remove a group of trials from the analysis select the grouping node click the right mouse button and click on the delete menu item If trials contained within a grouping node are deleted from the data viewer session they will be permanently removed from the tree view the EDF file has to be reloaded before information on that file can be accessed again 4 1 1 3 Trial Summary By clicking on the trial node S of the tree view information on participants performance in individual trials can be retrieved Once a trial is selected for analysis the middle panel of the Data Tab lists all of the visible events and messages in the trial and the bottom panel provides a general summary of performance in that trial The following table lists the trial level analysis variables Those fields that are editable in the viewer are marked with an asterisk Timestamp when the trial recording started in milliseconds since EyeLink tracker w
14. Edit Trial Grouping dialog choose the variable with which the grouping should be performed and press the Regroup button see the left panel of Figure 6 3 Multiple grouping variables can be selected or de selected by using the control key if no grouping variable is chosen grouping will be performed based on the data file each trial belongs to Once grouping is performed the trials will be listed by the conditions of the grouping variables selected see the right panel of Figure 6 3 The property panel of each group lists the label values of the grouping variables total number of trials and configurable interest area information for the group Thus the user can potentially apply an interest area template to all trials in the group see section 5 8 7 Using Interest Area Templates E E gt Data wt Preferences T Data il Preferences BCN evs FA H Single Feature Absent ngm Trial 1 m g Single_Teature Present a Trial 2 H Two_feature Absent H Trial 3 E g Two Feature Present EF Trial 4 ED Trial 115 EI Trial 5 EI Trial 118 EI Trial 6 aE Trial 121 CI Trial 7 CI Trial 122 al E Ki Field Value abel wo Feature Present a umber Tals 153 reated Created e ee Default Interest Grea test ias a icc oli Figure 6 3 Applying Trial Grouping by a Trial Condition Variable and Setting Interest Area Template for a Group of Trials EyeLink Data Viewer 2002 2008 SR R
15. MSG 3303399 V TRIAL GROUPING TYRE DIRECTION EyeLink Data Viewer 2002 2008 SR Research Ltd 85 Note Trial variables are space delimited Trial variables that do not exist in variable list for trial are ignored 7 3 Trial Message Commands The following message commands MUST be specified within the scope of a trial or the message commands will not be interpreted by the viewer IMPORTANT All message commands within the trial scope must start with a V directive or the command will not be interpreted and will instead appear as a regular message in the visible message list of the viewer Tip In almost all instances each of the following commands will be repeated for every trial of an EyeLink data file 7 3 1 Trial Variable Values Identifier Default TRIAL VAR DATA Description This message specifies the list of trial variable values for the trial The list of trial variable values must be in the same order as was specified in the TRIAL VAR LABELS command for the viewer to properly match the variable label with the variable value The command identifier can be changed in the data loading preference settings Note If this command is the same as the Trial Start Command TRIALID the values will still be extracted from the Trial Start Line however a V is not needed in the message Format V TRIAL VAR DATA lt trial variable list gt Example MSG S63 590 V TREALL VAR DATA Valuel Valued values 7 3 2 Single Tri
16. 107 Get the useful trial filename information from the string removing the file extension strepy text token token strtok text From the filename we get the information regarding the target presence setsize features as well as whether it is a practice trial presence token 1 0 setsize LOKe 2 103 features token 3 0 practice token 4 0 TRIAL VAR DATA message is recorded for EyeLink Data Viewer analysis It specifies the list of trial variables value for the trial This must be specified within the scope of an individual trial i e after TRIALID and before TRIAL RESULT eyemsg printf V TRIAL VAR DATA s s s S token practice Practice TestTrial discriminability High discriminability Low discriminability Leatures Two feature Single feature presence Present Absent items setsize 8 2 4 3 Trial Bitmap The spatial overlay view allows a trial to be viewed superimposed on the background image that the participant was looking at while the data was being recorded The Data Viewer loads the background image with the IMGLOAD token followed by a FILL TOP LEFT or CENTER subcommand The trial image file name and its default path can be written to the EDF file With such information we now can create our image file name here we set the image file as jpg file sprintf amage fn ss jpg token Create image file directory for w
17. 71 The above example illustrates the use of fixation sequence analysis Take interest area 6 pathless for example It received four fixations in total These fixations came from interest area 3 Fixation 4 6 Fixation 5 4 Fixation 8 and 7 Fixation 10 This is reported in the column IA FSA COUNT 6 There are three fixations starting from interest area 6 Fixation 5 to IA 6 Fixation 6 to IA 3 and Fixation 9 to IA 7 This is reported in the row with IA_ID being 6 pathless Please note that the user should also check the setting for Fixation Skip Count in the Output Analysis preference settings The fixation skip count defines the number should be an integer no less than 1 of fixations to skip when looking for the next interest area to use in the fixation sequence analysis variables of the Interest Area report The default setting is 1 and uses the next available fixation for the sequence analysis from the current interest area to all interest area A value of 2 uses the fixation following the next one for the analysis and so on 6 8 3 2 Regression Analysis A lot of the variables in the interest area report are intended for the regression analysis especially in the reading research The following example illustrates the use the interest area report in the regression analysis IA_ID a ae IA_LABEL Truth is a pathless Land A M He said IA DWELL TIME 3 F6 F7 F4 5 F8
18. A saved viewing session can also be opened by clicking the Open Existing Viewer Session tool on the standard toolbar or press Ctrl O 3 3 Saving a Viewing Session From the menus choose File Save Tip The viewing session can also be saved by clicking the Save Viewing Session tool on the standard toolbar or press Ctrl S EyeLink Data Viewer 2002 2008 SR Research Ltd 6 3 4 Saving an Existing Viewing Session to a Different File To save a viewing session to a file 1 From the menus choose File Save AS 2 Inthe Save As dialog box browse to the directory in which you want to save the document 3 In the File name text box type in the name for the document 4 Click Save Tip The viewing session can also be saved by clicking the Save Viewing Session As tool IGF on the standard toolbar 3 5 Importing an EyeLink Data File EyeLink EDF files can be imported into an already opened Viewing session or if no Viewing session 1s open a new one will be created for you when the data files are imported To import an EDF file 1 From the menus choose File Import Data gt EyeLink File s 2 Inthe Load dialog box browse to the location of the EDF file that you want to import and select it 3 Click Load Tip EyeLink data can also be imported by clicking the Import EyeLink Data File button 4 on the standard toolbar or press Ctrl l Note The time it takes to load the data files will depend on their size and heavily
19. PP es i N 1 fi COUNT a Y a ea l IA RUN COUNT 30 7 a l IA FIRST FIX PROGRESSIVE IA FIRST FIXATION DURATION IA FIRST RUN a DWELL TIME ae vis id IA SECOND FIXATION DURATION IA_SECOND FIXATION RUN IA SECOND RUN DWELL Tn IA REGRESSIONIN_ 0 E a O COUNT OUT _OUT_COUNT EyeLink Data Viewer 2002 2008 SR Research Ltd 72 ee ee PATH DURATION F7 F8 IA SELECTIVE Fl F2 F7 F4 F5 F8 REGRESSION PATH DURATION Take interest area 6 pathless for example IA REGRESSION PATH DURATION includes the first pass fixations on the interest area F4 F5 time spent in previous parts of the sentence following regressive eye movements F6 F7 and time due to refixations coming from the left before the eyes move past the interest area F8 The calculation of A SELECTIVE REGRESSION PATH DURATION only includes the first run fixation on the interest area F4 F5 and the refixations on the interest area F8 before the eyes enter next interest area with a higher IA _ID land IA FIRST FIX PROGRESSIVE checks whether later interest areas have been visited before the first fixation enters the current interest area Therefore this variable would be 0 for the interest area is because it was fixated on Fixation 7 while Fixations 4 and 5 were on later part of the sentence pathless IA REGRESSION OUT checks whether at least one regression was made from the current interest area to previou
20. angle blink around direction distance duration start time end time pupil size trial span the interest area in which the fixation is located the nearest interest area and whether the fixation has been selected for analysis In addition the report contains labels of the data file data file and individual trials as well as other user defined variables see section 6 6 2 Variables in the Fixation Report for the complete list of variables and their meanings 6 8 Interest Area Report Interest area report provides a columnar output of eye movement data for each interest area in a trial Each row of the report represents an interest area arranged in an ascending order of the interest area ID 6 8 1 Obtaining an Interest Area Report To obtain an interest area report adopt the same procedure as in obtaining the trial report except from the menus choose Analysis Report gt Interest Area Report EyeLink Data Viewer 2002 2008 SR Research Ltd 65 6 8 2 Variables in the Interest Area Report Currently the interest area report provides information for the following variables RECORDING SESSION LABEL Label of the data file DATA FILE File name of the recording EYE USED Which eye s data LEFT or RIGHT is used to create this report IA AREA Pixel area for the current interest area IA AVERAGE FIX PUPIL SIZE Average pupil size across all fixations in the interest area Dwell time 1 e summation of the duration acros
21. sub command 7 3 3 1 Image Loading Fill Full Screen Identifier FILL Description EyeLink Data Viewer 2002 2008 SR Research Ltd 87 This message specifies the image to be used as the background for the spatial overlay view of a trial within the viewer The image is sized to fit the dimensions specified in the DISPLAY COORDS command message The image should be represented as a relative path The viewer will look for the image in the following order 1 In the default image directory specified in the general preference settings 2 In the directory the EyeLink data file is loaded from 3 In the directory the viewer application is running from Format W IMGLOAD FILL lt relative image path gt Example MSG 3388468 V IMGLOAD FILL Sac blur jpg 7 3 3 2 Image Loading Top Left Identifier TOP LEFT Description This message specifies an image to be used as a segment of the spatial overlay view of a trial within the viewer The image size 1s not changed unless width and height parameters are also specified and will be positioned by using the x and y positions specified as the top left corner of the image The image should be represented as a relative path The viewer will look for the image in the following order 1 In the default image directory specified in the general preference settings 2 In the directory the EyeLink data file is loaded from 3 In the directory the viewer application is running from Format IV TM
22. 120 Figure 8 12 Obtaining a Trial Output Report ee eecceccceeeeceeeeeeeeeeeeeeeaaeeeeeeeeeseeees 121 Figure 8 13 Response Time in msec and Number of Fixations per Trial as a function target presence and display size in both the single feature SF and two feature TF search tasks in the high discriminability N 8 and the low discriminability conditons N S aa A a A 122 Figure 8 14 Obtaining a Fixation Output Report ssseeesesseseeseeeeeeerereereerererrrrrrrrerreens 123 Figure 8 15 Average proportion of fixations assigned to distractors sharing target color shape orientation in the single feature search task top panels and to distractors sharing target color shape color orientation or shape orientation in the two feature search task bottom panels as a function of saccade amplitude Note that results for saccades smaller than 1 are not reported because of insufficient data points in some SUNS E tenors sas euse E E EA A E E E E E TE E 124 List of Tables Table 1 Average percent of fixations by discriminability and search task for the first fixations following a short below median and long above median initial saccadic EE r E E E E E E A T T TT 125 Table 2 Average percent of fixations by discriminability and search task for the first fixations second fixations and all fixations eee cece ceecccsecceeccessceeeccesscuseees 125 EyeLink Data Viewer 2002 2008 SR Research Ltd vil 1 Introduction T
23. 5 Samples Samples can be toggled on off by clicking the Toggle Eye Sample Visibility button amp in the desktop toolbar In the spatial overlay view Figure 5 8 left panel the samples are overlaid on the trial bitmap forming the sample path of the viewing process In the temporal graph view Figure 5 8 right panel the xy coordinates of the samples as well the concurrent pupil size are plotted as a function of trial time a Trial iew text Trial 1 eja S ejeja eja BuSk did oe eswspapers or he would have krrown that trouble was brewing iotalone for himselfbut for dverytide ater be rauccle an ratre fi OL dog strong of musele and with warm t rgta P 4 l l l l Ca ger otf protectthem fromthe frost Buck ived a 4 bicck oHse t he sumkissed anta arave lley Judge ers place HPvas cailed _it steod backfromthe road alf hidden tamong the trees through Which glimapses coule_be caught of Figure 5 9 Sample Spatial Overlay View left and Temporal Graph View right of Raw Sample Data the wide sool ye as Mt Note By default samples are not loaded into the viewer when a data file is imported To load samples into the data viewer change the Load Samples property in the Preferences Data Loading tab Tip In the Spatial Overlay trial view if samples are visible at the same time as events when an event is selected all samples used to generate that event are also selected 5 8
24. 5 3 on discussion of three time periods used in Data Viewer As a result the values of CURRENT FIX END and CURRENT FIX START which are calculated relative to TRIAL START TIME will be different depending on whether a valid reaction time definition 1s found for the trial Note Messages written in the EDF file will be associated with an event closest in time So for a fixation report the message could appear during a preceding saccade PREVIOUS SAC MSG ora following saccade NEXT SAC MSG In very rare cases the message can be written to both saccade and fixation events 1f the message was written out after the last sample of a fixation or saccade but before the first sample of the following saccade or fixation Note A run of fixations refers to a group of consecutive fixations that are directed towards the same interest area Thus for example the interest areas of 10 fixations are A A B A A A C A E D Therun count will be 7 The following table summarizes the values for some relevant variables Variables i AA a IB ja A A C a E ID Bun dnot listed inthe variable ts L1 7 12 3 3 3 a 3 te tt CURRENT FIX INDEX 3 l4 15 l6 7 ila REA INDEX irae ae A REA FIX COUNT ira a A A E REA RUN ID iso ab AR EST_AREA i INTEREST AREA CURRENT FIX RUN INDEX FIX RUN INDEX a e We A Ne a ae a EE 6 6 3 Configuring the Fixation Report In addition to excluding some trials by entering a string in the Exc
25. 68 307 2 416 17 527 1 256 14 166 1 378 45 840 0 934 40 088 1 146 14 073 1 058 56 209 4 789 26 342 3 245 17 449 2 007 63 855 3 515 20 733 20 64 15 412 1 694 Note C color S shape O orientation CS color shape CO color orientation SO shape orientation LD low discriminability condition HD high discriminability condition SF single feature search task TF two feature search task 8 4 Reference EyeLink Data Viewer 2002 2008 SR Research Ltd 125 Williams D E amp Reingold E M 2001 Preattentive guidance of eye movements during triple conjunction search tasks The effects of feature discriminability and saccadic amplitude Psychonomic Bulletin amp Review 8 476 488 EyeLink Data Viewer 2002 2008 SR Research Ltd 126 9 Preference Settings All the elements of the EyeLink Data Viewer can be configured by the user from the Preference tab of the Inspector Window These include everything from the default colors used to the elements of how an EDF file is loaded All the changes can be saved allowing the changed preference settings to be loaded in subsequent viewing sessions Any preferences setting can be edited by clicking on the value cell and changing the value For string and number values be sure to press Enter after making the change to register your input with the application Tip The changed preference settings can be saved by clicking the right mouse buttons and clicking on Save Pro
26. 9 D_RCN D_RCN 3 D_RCN D_RCN D_RCN DRON fais 120m02 Hioh_discrimina single feature Present D_RCN D_RCN D_RCN D REN D_RCN T Sa Sa Sa Ss Ss Ss Ss Ss Ss a 2 ololololololoalololol ololo UP el O L a O L a D L a D La T T T T T r T r T r T rT r T rT rT at ui cr or D_RCN D REN Trial 22 D_RCN D_RCN D RCH Trial 25 ingle Feature Absent Figure 8 6 Using the Trial Variable Value Editor Modifying a Default Value at Fa E prp prg pr g pr p p p m at ur ur ui m or T i ur T Pi e ha ha m Mi Be ho Pa Pa Po Po ee Pa E P hs mi PJ In case an analysis is being conducted on an old EyeLink data file in which the trial conditions were recorded following the TRIALID or other message whereas the trial variable labels were not recorded to enable the correct loading of trial condition values the user has to change the preference settings of data loading see Figure 8 7 Click the preference tab of the Inspector window and select the Data Loading node The default value for the Trial Variable Values Message field is TRIAL VAR DATA Replace it with TRIALID or other message following which the condition values for a trial were recorded and press the enter key to register the change Now select the Data Loading preference node again click the right mouse button and select Save Properties as Defaults To enable this change to take e
27. Bad round a yeliayymetal afd becaus isteamshifand transportation companies werebooming the fin Inc thousands of rr men were rushi into the Nol oithian These men waltedcclbgs and the dogs they Wanted were nea dogs withStrong muscles by which to i ene furry coats to protect them it Uh frost Butk lived at a bi Gfouse i in th sun kissed Santa Clara Valley Judge Miller s placedit was called It Stood backfrom thetoad Half a hidden afitong therees throtgh which glimpses couldbe caught of 720 Hidden aly ie the Wide ool veranda that ran around its four sides Figure 5 1 Sample Spatial Overlay View of Fixation Events The trial view window Figure 5 1 right panel shows either a spatial overlay view or a temporal graph view of the fixation events In the former view fixations are represented as a hollow circle in the corresponding x y coordinates on the trial bitmap with fixation duration displayed near the top left corner of the circle In the temporal graph view fixations are represented as a filled block All fixation events in a selected trial are listed sequentially in the middle panel of the inspector window Properties of a selected fixation are shown in the bottom panel of the inspector window Each field of the fixation event property is described in the following table Those fields that are editable in the viewer are marked with an asterisk EyeLink Data Viewer 2002 2008 SR Research Ltd 22
28. Buck did not read the newspapers or he would have Known that t z ER trouble wat brewing not alone for himself but for every tigd e vw ater ial P 2 big dog strong of muscle and with warm long hair from Puget Sound to ral Oo Trial 4 San Dicgo Because men groping in the Arctic darkness Nad found s C Interest Area Templates a yellow metal and because steamship and transportation companies were booming the find thousands of men were rushing inte the Northland These men wanted moms and the dogs they wanted were heavy dogs with strong muscles by which to toil and furry coats to Button 166ms Button 260ms Protect them from the frost Button 23584ms Buck lived ata big House in the Sun kissed Santa Clara Valley Judge Miller s Place tt was called It stood back from the road halt hidden among the trees through which glimpses could be caught of the wide cool veranda that ran around its four sides ja g Trial iew text Trial 1 m f E3 ajal x 0 ms 1971 3942 5913 7384 9855 11826 13798 15769 17740 19711 21682 2 al l l l l l l l l RT End Event 808 Hidden o09 Figure 6 9 Reaction Time Graphics in Both the Spatial Overlay View and the Temporal Graph View of the Trial View Window 6 4 Interest Periods EyeLink Data Viewer 2002 2008 SR Research Ltd 50 Besides the above mentioned reaction time d
29. Data Tab Right Preference SDA PEET E sac EE ue EN E T A EAA tea andes ae ee 10 Figure 4 3 Lime Trial View WHdowWS aiseee a ie Hee 15 Figure 4 4 Sample Spatial Overlay Trial View 0 cccccccccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 16 Figure 4 5 Sample Temporal Graph Trial View ccccccccsscececeeeeeeeeeeeeeaeeeeeeeessseeees 17 Figure 4 6 Sample Playback Animation View cc cccsseseseeeseessesseeseseseseeesseseseeeeeegs 20 Figure 5 1 Sample Spatial Overlay View of Fixation Events ccccccccssssessseeeeeeeeees 22 Figure 5 2 Diagram for Angle Calculations norii S 24 Figure 5 3 Drift Correcting Fixations on One Line of Text 00 0 0 eccccceeeeeeeeeeeeeeeeeeees 25 Figure 5 4 Options for Fixation Cleaning ccccccscssnessssssssesseseeeeeceseccesensanennacaasseenees 21 Figure 5 5 Sample Spatial Overlay View of Saccade Events cccccccccscssssssseeeeeeeees 28 Figure 5 6 Sample Temporal Graph View of Blink Events 0 0 0 0 csesesseeeeeeeeees 30 Figure 5 7 Sample Temporal Graph View of Message Events Note that the default size of the message symbol in the temporal graph preference settings has been changed PEE AERE eI ea eae a een eee Te TERN ee ent NEEE aN A Tee 31 Figure 5 8 Sample Temporal Graph View Showing the Button Events Note that the default size of the button symbol in the temporal graph preference settings has been chanogd jasena aca aasdecinceslsun dela dastions aan ddail
30. Events Identifier MESSAGE Description This will treat the first occurrence of a matching message as the end event for reaction time calculation Pre Trial Message Command Format V_ RT MESSAGE lt rt start msg gt lt rt end msg gt CONDITION LABEL 1 condition value 1 CONDITION LABEL 2 condition value 2 Trial specific Message Command Format iy NCR MESSAGE sre start msg lt rt end mog Note Condition labels and their values are not required for the trial specific message command and optional for the pre trial message command 1f not specified the RT definition is applied to all conditions Example MSG 329381 V RI MESSAGE SYNCTIME END RTI 7 4 5 Reaction Time Definition Set Identifier FILE Description EyeLink Data Viewer 2002 2008 SR Research Ltd 99 When a large number of RT definitions have to be specified it is easier to first record all RT definitions in a file and later on the viewer can read the RT definition file with the V_RT FILE command In a reaction time definition file each line represents one RT definition which is written in the same format as the pre trial message command for each respective type of RT end event except that in this case V_RT token is not necessary Pre Trial Message Command Format VORE EILE lt pelative path gt Example MSG 329281 V RT FILE rtvdefa l rts 7 5 Changes in the Sample Experiments The preceding sections list the special messages an
31. Interest Areas To access information on interest areas in a trial first click on the interest area button E of that trial in the tree view panel of the inspector window see Figure 5 9 The node will read as Custom Interest Area Set if custom interest areas are loaded or created but as Empty Interest Area Set if no interest areas are defined The middle panel of the inspector window lists all available interest areas in that trial The following EyeLink Data Viewer 2002 2008 SR Research Ltd 34 table lists the properties of an interest area Those fields that are editable in the viewer are marked with an asterisk olalalsls Moloy e s gt e m elf mares 5 x M Trial View text Trial 1 Tooge Interest Area Visbiity eeffes m col ea to alal A J Untitled grs H text E m Trial 1 a My 3 trouble brewing not alone for himself every tide water a Trial 4 J Interest Area Templates aog strong of muscleland with warm long hair from Puget Souna io San Diego Because men Joroping in he Arotio darkness nad found_ alyliow metal ana becauce stoamshiplanalranspertaton eompanies Northland These men wanted doge jand the dogsthey wantod wore heavyldogs with strong muscies by which toltotanalfury soats to protect frost hidden among the ttes through which glimpses could beleaughtof_ the wide coolverandalthat an around its oursides
32. Moov SE B semen P Trial View picture Trial 1 Data Preferences 9 Untitled ews B P ae Bg Ee a Trial B a Trial 3 Ey Interest 4rea Templates O x P Fixation 8ms Saccade 472ms o Trial iew picture Trial 1 GFixation 528ms 2 MWM ee do Saccade 664ms 2 e a TP Fixation 684ms TP Saccade 1128ms S rii a Fk ak ron Fixation 1160ms 45 gt Saccade 1404ms lt gt Fixation 1416ms 44 lt gt Saccade 1668ms 4 TP Fixation 1692ms 206 Saccade 1880ms 229 hes Fixation 1900ms 2146 ms 36 ms kawk fe A f Start EyeLink Data viewer 3 20 PM Figure 4 3 Tiling Trial View Windows 4 3 Spatial Overlay Trial View The Spatial Overlay view see Figure 4 4 is selected by pressing the 5 button in the Trial View window This view lets you look at events and samples by placing them where they were detected in space If the image that was presented during the trial is available it can be placed in the overlay view EyeLink Data Viewer 2002 2008 SR Research Ltd 15 a Trial iew picture Trial 1 i O x AF Figure 4 4 Sample Spatial Overlay Trial View The following buttons are available from the spatial overlay mode Import Area of Interest File View Trial Play Back Animation Seles the playback animation mode _ an interest area set file and sets the interest areas for this trial Any existing interest ar
33. Solec ONE FIXIS earn Rene eee a ay eee See apn ee peer 24 S22 Mers mo FAI OIG saaana e E EATE E ached EE 24 S213 Dri Come cus Fix ati gests soa ei sssdtesuisiedescntivadelasbedeessh A 24 5 2 3 1 Drift correcting a Group of Selected Fixations ccccccccceceeeseeeeeeees 25 5 2 3 2 Precise Drift Correction of a Single Fixation c cc ceeeeeeeeeeeeeeeeeeeees 25 EyeLink Data Viewer 2002 2008 SR Research Ltd 1 ILo CEE Fa ONS oer e a 26 5 3 RSs 0 O72 16 kc eia A a a a eR A Neer Te 2 5 31 Mersina SACCACCS siti xe En tirana cua tumeeaneeeseammeeemetes 29 34 ABI EVM Suie a a ducdncoutar 29 5 5 Messan OSa a E te en eee Rene ee 30 Sad Hopon Message LIS eserin Te An nA N AT 31 5 6 Butom Evei Seneca started tee a E T aaa a2 3 Sa ois L E O I A E EI E E E T E E PE A TE E ET 34 5 8 litere stAT AS eo e aa ssue dence seniatceteee ete mee aanean meee atecteee ieee 34 5 8 1 Manually Creating Interest Areas ccccccccccccceceeeeeeseeessseseeeeeeeeeeeeeees 36 5 8 2 Creating Interest Area Image Segmentation cccccssseeeeeeeeeeeees 37 5 8 3 Savine TAtErest ATOI Seinn E E Maredseeataeine 38 5 8 4 Importing Interest Area File for a specific trial ceeeeeseseeeeeeeeeeeeees 38 5 8 5 Emptying Interest Area Set for a trial 0 0 ccccccssssssssseseeceeeeeeeeees 38 5 8 6 Loading Interest Area Template ccccccccccccccecececeesessssseeeeeeeeeeeeeeeees 38 5 8 7 Using Interest Area Template Saci cas
34. a a Stee 54 6 5 2 Variables m the Trial RepoTtunicini i na R 55 6 5 3 Usmo LHaLREDOF soprete ten EE E EE T 57 6 5 4 Configuring the Trial Report ennnnnonssseooooeeeeeeeeeennnnnnssssssssssseeerrreeeeeeo 58 6 6 FIXAUOM RPO ee A a a atau eee auaeaees 59 6 6 1 Obtain a FPixaton Repol besnenie e a OEG E RES 59 6 6 2 Vatiables m the Pixaon REDO esineen a a 59 6 6 3 Contiguring the Fixation Report lt cesactsientesindes uel aaeenenisonerneteeies 64 EyeLink Data Viewer 2002 2008 SR Research Ltd 11 6 7 BC CAC ING PO r a E AAO AE EA satay auatoca au OE 65 6 7 1 Obtaining 4 Saccade RCN noises cess thvatisee dai es 65 6 7 2 Variables im the saccade REPOT odiran E EA 65 6 8 MrS tAr REDO aeei ane a a i 65 6 8 1 Obtaming an Interest Area Report cc issencstettei delaras 65 6 8 2 Variables in the Interest Area Report ecccccccccccceeessseeecceeeeeeeeeeeees 66 6 8 3 Usine Interest Arca REPOT eer ee i Ga catenins sane 70 6S1 Fixallon Sequence AMG Sis occ eset as teiar eat eae av ees 71 O82 REESS NANAS Seea E EEA EEE avmeetieseteestens ae 6 9 Dam ple O UlpUt REPO sao a A 73 6 9 1 Loading Samples into a Viewing SeSSION c ssessesseeesseessseseeseeeeeens 73 6 9 2 Obtaining a Sample Output Report cccccccccccceeceeeeeeeeeeeseeeseseeeees 74 6 9 3 Variables in the Sample Output Report ccc cccccessseeeeeecceeeeeeaeeeees 74 O10 M ssadge Output RED OU iiss nts EE S E nee eaesanameanees 71 6 10 1 Obtaining a Message Outpu
35. are editable in the viewer are marked with an asterisk Eye Trial time when the blink ends Duration of the blink Whether the current blink is hidden from viewing Color To achieve better visibility the color of the currently selected blink can be changed by clicking on the color toolbox EyeLink Data Viewer 2002 2008 SR Research Ltd 29 o EyeLink Data iewer Oj x File Edit Analysis Window Help plelslala elefaja s Moos veEs o e Mrama Pa fo Trial View TEST Trial 1 Toggle Blink Event Visibility O x amp Data ai Preferences 9 Untitled evs 0 ms 463 927 1391 1855 2318 2782 3246 3710 4174 4637 5101 551 l l l l I l l l l i a a m Trial 7 lt p Blink 490ms S Blink 1018ms 303 lt p Blink 3182ms Figure 5 6 Sample Temporal Graph View of Blink Events 5 5 Messages Messages including message for built in EyeLink commands can be placed in the EDF file to mark the start and end of a trial or important events such as display changes Message events see Figure 5 6 can be toggled on off by clicking the Toggle Message Event Visibility button in the application desktop toolbar A message is represented as a colored triangle in the temporal graph view and a colored square in the spatial overlay view centering on the current gaze position Each field of the message event property is listed in the following table Thos
36. as an interest area template or to be imported into another trial 1 Click the Save the Interest Area Set to Disk l button on the spatial overlay window toolbar 2 Inthe Save dialog box browse to the directory in which you want to save the interest area 3 In the File name text box type in the name for the file 4 Press Save button 5 8 4 Importing Interest Area File for a specific trial For each individual trial interest area can be imported 4 Click the Import Interest Area File button 4s on the spatial overlay window toolbar 5 In the Load dialog box browse to the location of the interest area file that you want to import and select it 6 Click Load Note This operation will delete any existing interest areas in the trial 5 8 5 Emptying Interest Area Set for a trial To empty the current interest area set for a trial 1 Click the trial whose interest areas are to be emptied in the tree view 2 In the property panel of the trial find the entry Interest Area Set and choose the value of Empty Interest Area 5 8 6 Loading Interest Area Template If the same interest areas are used for several trials instead of repeating the procedure of creating interest areas for each individual trial an interest area template can be loaded to supply the segmentation information for those trials To load an interest area template or multiple interest area set files 1 From the menus choose File Import Data g
37. at a later date 1f required Events can also be deleted from within the Data Viewer This is useful for example 1f the researcher inspects a specific fixation or saccade event and determines that the event detection performed by the EyeLink on line parser did not satisfy their needs If a fixation or saccade event is deleted the surrounding saccade or fixation events are automatically merged to keep the event structure consistent The position of a fixation event can also be adjusted if required This is only suggested if it is obvious to the user that improper system setup or calibration has resulted in a trial s fixation data containing significant drift that can be easily corrected manually Any event that is adjusted in this fashion is flagged so that it is clear what events have been manually altered Optionally if the position of a fixation 1s adjusted the adjoining EyeLink Data Viewer 2002 2008 SR Research Ltd 2 saccade end point and start point are also adjusted so that the saccade positions are kept consistent with fixation positions 1 5 Interest Periods and Reaction Time Definition For each trial the user may selectively view and perform analysis on data within a specific period of time within a trial Interest Period The EyeLink Data Viewer allows the user to create interest periods based on messages and button events The created interest periods are added to the interest period list The user can navigate between dif
38. can be changed in the data loading preference settings Format TRIALLEY lt Trial ID value vets Example MSG 3362269 TRIALID PIX1 images sacrmeto jpg EyeLink Data Viewer 2002 2008 SR Research Ltd 83 Note Ifthe trial start message is not found or if no trial start message is defined for the viewing session the START message is used to indicate the start of a trial for the Viewer 7 1 2 Trial End Message Identifier Default TRIAL RESULT Description This message defines the end of a trial for the viewer This is different than the end of recording message END that is logged when the trial recording ends The viewer will not parse any messages events or samples that exist in the data file after this message The command identifier can be changed in the data loading preference settings Format TRIAL RBESULY lt possible trial r esulu values gt Example MSG 3383842 TRIAL RESULT 0 Note If the trial end message is not found or 1f no trial end message is defined for the viewing session the END message is used to indicate the end of a trial for the Viewer 7 2 Pre Trial Message Commands The following message commands if defined MUST be sent to the EyeLink data file prior to the Trial Start message defined above 1 e outside the scope of a trial as defined for the viewer If they are sent during trial recording these messages will not be interpreted 7 2 1 Trial Variable Labels Identifier Default TR
39. consider saving this as default setting This can be done by selecting the topmost preference tree node clicking the right mouse buttons and selecting Save Properties as Defaults EyeLink Data Viewer 2002 2008 SR Research Ltd 73 3 Once you have done step 2 this will make the properties persist over future data viewing sessions Now start loading in the EDF files 6 9 2 Obtaining a Sample Output Report To obtain a sample report adopt the same procedure as in obtaining the trial report except from the menus choose Analysis Report gt Sample Report 6 9 3 Variables in the Sample Output Report Currently the sample output report provides output for the following variables RECORDING SESSION LABEL Label of the data file along the x axis across two eyes along the y axis across two eyes Gaze coordinate along the x axis across two eyes Gaze coordinate along the y axis across two eyes Index of the interest area in which the current sample average across two eyes falls BEL sample average across two eyes falls AVERAGE VELOCITY X Velocity value in degree second along the x axis across two eyes AVERAGE VELOCITY Y Velocity value in degree second along the y axis across two eyes HTARGET DISTANCE Distance between the head target and eye camera in millimeters for an EyeLink Remote recording Returns a missing value if the head target was missing or 1f the data was recorded with a
40. current fixation is shorter or equal to the distance threshold If both the previous and next fixations meet the above criterion the current fixation will be merged to the longer one of the two STAGE 2 This stage is similar to STAGE 1 except for a different fixation duration and a distance value For this stage to be effective a shorter duration and a longer distance threshold should be used compared to Stage 1 STAGE 3 Data Viewer goes over the entire data and checks for interest areas which include at least three fixations smaller than the threshold duration and no fixations larger than the threshold duration In such cases the shorter fixations are merged into the larger ones STAGE 4 Data Viewer goes over the entire data and deletes every fixation which is shorter than Minimum duration or larger than the maximum duration threshold If Delete Fixations Outside Interest Area box is checked this will remove those fixations falling out side of any interest area Important If no interest area is defined all fixations will be removed 5 3 Saccades EyeLink Data Viewer 2002 2008 SR Research Ltd 27 o EyeLink Data iewer Oj x File Edit Analysis Window Help olelsiala ele ole sis Molom elBl e 5 e e ime pea o Trial View text Trial 1 Toggle Saccade Event visibility 5 x Data gf Preferences AE fa As c A iB 9 Untitled evs text 2 l a
41. definitions If the RT end event 1s the press release of a button records the button ID otherwise records qq RT EVENT END TIME End time in milliseconds since EyeLink tracker was activated of the end event If end event is not an eye event fixation or saccade event this variable is equal to RT EVENT START TIME RT EVENT INDEX Sequential order of the end event 1 when EyeLink Data Viewer 2002 2008 SR Research Ltd 56 OUI scenes type end event is not a message event records 4 RT EVENT POSITION X Y Records the X Y coordinates of the fixation or saccade end event and sets for a button or message end event RT EVENT START TIME Start time in milliseconds since EyeLink tracker was activated of the end event qq RT EVENT TYPE The way in which the trial is ended BUTTON FIXATION SACCADE MESSAGE or NO MATCH RT START TIME Start time in milliseconds since EyeLink tracker was activated of RT definition for a trial RUN COUNT Total runs of fixations in the trial two consecutive fixations in the same interest area belong to the same run SACCADE COUNT Total number of saccades 1n the trial SAMPLE COUNT Total number of samples in the trial START TIME Timestamp when the trial recording starts in milliseconds since EyeLink tracker was activated TRIAL LABEL Label of the trial Besides these default variables additional trial variables will be listed 1f they ha
42. example when fixations from different lines are selected The tolerable deviation threshold and the X Y dimension of alignment is set to 30 as a default and can be modified in the general trial view preference settings a EyeLink Data iewer Oj x bialsiaa DOE EIS er Beljeje a o H rutmareioa Pa o Trial View text Trial 1 01 x Data w Preferences bella 9 Untitled evs 3 text 224 184 124220 E Em Buek didAot d ad thehewspapers or he Kuld havOknovh that Trial 184 Ta lads trouble wats i brewing nd Palone fokhimest but for Dery tide lt ivater ai het eek Cron Teele dog Strong Gf m muscle and Witwarm long hair from Puget Sound to 188 SamDiege Because men Groping ifthe Arctie darkness rr He a yeliow metal afd becaus teamship and transportation companies werebooming the find thousands of m n were rushing into the Northland These men wahited dogs and the dogs they Wanted Were Henn dogs with Strong muscles by which to toll and furry coats to protect them fromthe frost Butk lived ata big house i in the sun kissed Santa ClaraValley Judge Mitler s placecit was called It Stood back from the road half hidde atong the trees through which g glimpses coul cbe caught of the Wide ool veranda that ran around its Bar sides p Cut Copy Paste Hide b Unhide All Delete Delete Split Merge Ctr
43. interest area Type of interest area rectangular elliptic or freehand Top side pixel position of non freehand IA IP END TIME End time in milliseconds since EyeLink tracker ie was activated of the interest period viewing session was activated of the interest period durations for the whole trial EyeLink Data Viewer 2002 2008 SR Research Ltd 69 TRIAL START TIME The start time in milliseconds since EyeLink tracker was activated of the trial In addition other user defined trial variable labels will also be listed Note since version 1 3 of Data Viewer all eye event start and end times in the interest area report are made relative to trial start instead The absolute time of eye events can be obtained by adding TRIAL START TIME 6 8 3 Using Interest Area Report The data output in the interest area report depends on the setting of the interest period filter see section 6 4 2 or Figure 6 13 only those fixation and saccade events falling within the active interest period will be reported Ifa valid reaction time definition 1s found in a trial the TRIAL START TIME will be set as the start as the reaction time definition otherwise this will be set as the start of trial recording see section 6 5 3 on discussion of three time periods used in Data Viewer As a result the values of all of variables marked with a symbol which are calculated relative to TRIAL START TIME will be different depending
44. into the Viewer any existing Reaction Time Definitions for the Data Viewing Session are removed and reloaded from the data file being imported Therefore it is important that each data file contain all the pre trial condition based command messages required for the full analysis not just for the given data file Any previously set custom trial specific reaction time definitions are not affected when a new data file is loaded 7 4 1 Button Events Identifier BUTTON Description This will treat a particular button press release as the reaction time end event Pre Trial Message Command Format EyeLink Data Viewer 2002 2008 SR Research Ltd 96 VORE BUTTON lt U start msg gt lt button id gt lt state gt CONDITION LABEL 1 condition value 1 CONDITION LABEL 2 condition value 2 Trial specific Message Command Format nv NOIGRT BUTTON lt PGLStart msg gt lt button id lt state gt Note Button id refers to the intended button ID from 1 to 8 use 0 for any button event Button state could be 0 button release or 1 button press Condition labels and their values are not required for the trial specific message command and optional for the pre trial message command if not specified the RT definition is applied to all conditions In case both a condition based pre trial message command and a custom trial specific message command are applicable for one trial the trial specific command will override the more genera
45. is used to create this report FIXATION COUNT Total number of fixations in the trial INDEX Sequential order of the trial in the recording INTEREST AREA SET Setting of the interest area Custom Interest Area Set if interest areas are loaded created and Empty Interest Area Set if not was activated of the interest period Start time in milliseconds since EyeLink tracker was activated of the interest period Total number of messages in the trial PUPIL SIZE MAX Maximum pupil size in arbitrary units Typical pupil area is 800 to 2000 units while pupil diameter is in the range of 1800 3000 units Note that PUPIL SIZE MAX PUPIL SIZE MEAN and PUPIL SIZE MIN fields will output a missing value if samples are not loaded into a viewing session see Data Loading Preferences PUPIL SIZE MAX TIME EDF Time of the sample with maximum pupil size Note that this field will output a missing value if samples are not loaded into a viewing session see Data Loading Preferences PUPIL SIZE MAX X X position at PUPIL SIZE MAX TIME PUPIL SIZE MAX Y Y position at PUPIL SIZE MAX TIME q REACTION TIME Configurable response time determined by the Reaction Time Definition associated with the trial This variable returns a if the trial does not have an RT end event 4 RT_ DEFINITION LABEL Label of the RT definition if undefined CUSTOM RT if the RT definition is a custom one see Section 7 4 on reaction time
46. listed The total visual angle covered in the saccade is reported by lt ampl gt which can be divided by lt dur gt 1000 to obtain the average velocity Peak velocity is given by lt pv gt The horizontal and vertical eye position angular resolutions in pixels per visual degree are given as well EyeLink Data Viewer 2002 2008 SR Research Ltd 81 6 11 2 3 Blink Events Blink events are recorded in the format of e EBLINK lt eye gt lt stime gt lt etime gt lt dur gt This reports the eye used in the recording the time of the first and last sample 1n the blink and computes the duration of the blink in milliseconds 6 11 2 4 Message Events Messages are recorded in the format of e MSG lt time gt lt message gt A message line contains the text of a time stamped message The lt message gt text fills the entire line after the timestamp lt time gt and any blank space following it 6 11 2 5 Button Events Button events are recorded in the format of e BUTTON lt time gt lt button gt lt button pressed gt Button lines report a change in state of tracker buttons The lt button gt reports which button has changed state The lt button pressed gt value will be true if the button has been pressed false if it has been released EyeLink Data Viewer 2002 2008 SR Research Ltd 82 7 Protocol for EyeLink Data to Viewer Integration The EyeLink Data Viewer can interpret a set of message commands from an EyeLi
47. of bottom right corner EyeLink Data Viewer 2002 2008 SR Research Ltd 41 5 8 13 Resizing Freehand Interest Areas A freehand interest area can be resized by following these steps 1 Select the interest area 2 Hold the ALT key down 3 Place the mouse over the vertex to be dragged the arrow cursor changes into a hand cursor 4 Press the left mouse button and drag the vertex to the desired location 5 Release the mouse button 5 8 14 Deleting Interest Areas To delete interest areas 1 To delete interest areas without removing any events falling within first toggle off all event visibility 2 Select the interest areas 3 Press the right mouse button 4 Select the Delete option from the popup menu 5 Confirm that the IAs should be deleted Tip Interest areas can also be deleted by clicking the Delete Selected Items button i or the Cut Selected Item button on the desktop toolbar 5 8 15 Splitting Interest Areas Rectangular and elliptic interest areas can be split either horizontally or vertically You can split many interest areas at one time by selecting multiple IAs To split all selected IAs 1 Select the IA s to split 2 Press the right mouse button 3 Select Split from the popup menu 5 8 16 Merging Interest Areas Neighboring rectangular interest areas can also be merged To do that 1 Click Toggle Fixation Event Visibility button on the trial view window toolbar so that the fixation events will no
48. on whether or not you are loading samples from the data file A 60 minute binocular 5 00Hz recording will take 3 4 minutes to initially parse the data file if loading all events and samples Once you have saved the viewing session reloading the session takes a fraction of the time because the data is in a format optimized for the Data Viewer Note To load data files using the SceneLink gaze mapping please make sure to enable the Enable SceneLink Gaze Mapping and Generate SceneLink Frame Messages in the Data Loading preferences settings before you import the data files Make sure that you have already created the lookup tables for the trials in SceneLink EyeLink Data Viewer 2002 2008 SR Research Ltd 7 4 Data Viewer Windows The EyeLink Data Viewer uses a desktop framework that contains all windows of the Viewer application Once a Data Viewing Session DVS is opened and EyeLink data is loaded two windows will appear the Inspector Window on the left and the Trial View Window on the right The Inspector Window enables the user to choose data to be viewed to review Statistical summaries and to configure default application settings The Trial View window allows a graphic examination of the data of the selected trial Both windows can be minimized and maximized within the Application desktop The figure below shows the viewer desktop after loading the sample picture edf file e EyeLink Data iewer File
49. on whether a valid reaction time is found in the trial If the Trimmed Spanned Fixation Duration setting of the Data Filter preference is enabled the duration start time and end time of the fixations that overlap with the start or end of the interest period will be adjusted accordingly Some variables in the interest area report may be influenced by the outlier fixations that do not belong to any interest area For example the presence of an outlier fixation may break the run of fixations on a particular interest area and therefore shortens the measure of IA FIRST RUN DWELL TIME and increases the IA RUN COUNT value Therefore users should ensure that all fixations are assigned to a particular interest area before creating an interest area report 1f run related measures are important Users can either manually move the position of those outlier fixations or more conveniently enable the Use Nearest Interest Area for Outlier Fixations option of the Output Analysis preference settings Interest area report was designed to support analysis of data from different research paradigms and therefore the user only needs to use a small portion of variables in one output If you have lots of interest areas in a trial including A FSA COUNT and IA FSA DURATION in the output report may take a very long time for the Viewer to generate the report A progress dialog see Figure 6 14 will be displayed while creating the report The user may abort the p
50. select the fixations and click the Merge Selected Items button LS on the toolbar or click the right mouse button and select merge Note Only two or more temporally contiguous fixations can be merged If fixations are selected that are not temporally contiguous only the neighboring fixations will be merged 5 2 3 Drift Correcting Fixations Sometimes a drift in the gaze position may occur due to poor system setup headband slippage or excessive head body movement Normally the eye tracker operator would notice this problem and perform a recalibration or drift correction If however the issue was not addressed during recording it may be possible to manually adjust the fixation events so that some degree of data analysis can still be performed EyeLink Data Viewer 2002 2008 SR Research Ltd 24 5 2 3 1 Drift correcting a Group of Selected Fixations To perform drift correction 1 Select the fixations to be drift corrected 2 Hold the ALT key down 3 Move the selected fixations with the cursor keys to the desired locations Tip In case several fixations on one single line such as in reading research are to be drift corrected another method is to select all of the desired fixations and press CTRL D to align them to the same Y position see Figure 5 3 This operation will fail if one or more fixations deviate more than 30 pixels in the Y dimension from the mean of the group of fixations to be drift corrected in a batch for
51. 449 7 3 5 3 Freehand Interest Area Identifier Default FREEHAND Description This message specifies the attributes of a freehand interest area for the trial Each trial can have a set of such freehand interest areas Format iV TAREA FREEHAND lt id gt lt X V gt lt Xj gt sar lt X y gt label string Note The label string parameter is optional x y refers to the x y coordinates of a point The x y coordinates of each point are separated by a comma Example MSG 2740540 V IAREFA FREEHAND 100 200 300 400 500 600 200 300 label text 7 3 5 4 Interest Area Set Identifier Default FILE Description When a large number of interest areas have to be specified such as in reading research it is easier to first write all the interest area information in a text file and later on the Viewer can locate and import the interest area file The v IAREA FILE serves this purpose In an interest area file each line represents one interest area recorded in the format of RECTANGLE id left top might bottom _ label fora rectangular interest area ELLIPSE id left top might bottom _ label for an elliptic interest area and FREEHAND id x y x y x y label for a freehand interest area EyeLink Data Viewer 2002 2008 SR Research Ltd 94 Format IV IAREA FILE lt relative file path gt Example MSG 2740540 V IAREA FILE segments example ias 7 3 6 Target Position Commands For experiments in w
52. AL VAR LABELS command when using TRIAL VAR command Default command token is TRIAL VAR Target Position String String used to specify the position of the targets at the specific message time Exclude Message String Any messages within the scope of a trial as defined by the Trial Load Start Message and Trial Load End Message containing the string will be 66 99 ignored by the Viewer Add a to separate multiple message strings Enable SceneLink Gaze Mapping If checked allows the user to load EDF file with mapped gaze data to scene video coordinates Generate SceneLink Frame Message If checked allows the user to generate frame number messages when loading file The frame number message will only be written if a lookup table has been created for synchronized playback of eye movement data over the scene video see section 5 1 of the EyeLink II Scene Camera User Manual Note The user has to save the preferences and reload the data file before the changes in the above preference settings take effect EyeLink Data Viewer 2002 2008 SR Research Ltd 130 9 3 Output Analysis The output analysis preference settings consist of the following elements foe General ae Data raang e De Data Fiters Data views Field Value Output Reports Mariable Delimiter 1 Missing Value l Decimal Places Include Hi Hidden Eve D Treat Hidden Event I Bracke Stings wE T Exclu
53. ART 0 waves 1 wav suggests that the event the message was referring to APLAYSTART actual happened at time 2435820 e Message text can be any string up to 100 characters in size that starts with a non numeric character e Lines that do not follow these rules are ignored MSG 2435806 14 V APLAYSTART 0 1 waves 1 wav MSG 2436376 14 V APLAYSTOP 12578 1 waves 1 wav 62798072 0 POSN 174 384 62798072 0 POSN 185 384 To load the message list file 1 Select the EDF file label in the treeview panel of the Inspector Window 2 Click on the right mouse button and select Import Message List 3 In the following Open dialog box go to the directory where the message list file is stored and choose the file E Data mi Preferences Delete Create Fixation Map m ri Select Trial Background Image EH Interest Import Message List After the message list file is imported into the session a dialog box will be presented to show the number of valid messages imported 5 6 Button Events Button events see Figure 5 7 can be toggled on off by clicking the Toggle Button Event Visibility button A button event is represented as a colored triangle in the EyeLink Data Viewer 2002 2008 SR Research Ltd 32 temporal graph view and a colored square in the spatial overlay view centering on the current gaze position The following table lists the properties of a button event Those fields that are editable in the vi
54. Data Inspector tree view shows the trial s data in a Trial View Window The user can have several Trial View Windows open at one time by right clicking on a trial in the Inspector window and selecting New Window in the popup menu 4 2 1 Selecting Data Elements to Display At anytime event visibility can be toggled on off within the Trial View Window For example the button in the Application Desktop toggles the visibility of Fixation Events EyeLink Data Viewer 2002 2008 SR Research Ltd 13 gt Toggle Fixation Event Visibility Toggle Saccade Event Visibility Toggle Blink Event Visibility Toggle Message Event Visibility Toggle Button Event Visibility Toggle Sample Visibility Toggle Interest Area Visibility 4 2 2 Cloning a Trial View From the menu choose Window Clone Window This allows for example both the temporal graph and spatial overlay views to be shown at the same time on the desktop You can tile the windows together Note that event selection in one view will automatically cause the same events to be selected in the other view 4 2 3 Tiling Cascading Windows To arrange all open trial view windows from the menu select Window Tile or Window Cascade Figure 4 3 shows an example of tiling three open trial view spatial overlay temporal graph and animation modes windows EyeLink Data Viewer 2002 2008 SR Research Ltd 14 e EyeLink Data iewer E j amp l xi jie aa ae S
55. Each RGB value should be an integer between 0 and 255 Format IV CLEAR lt red gt lt blue gt lt qreen gt EyeLink Data Viewer 2002 2008 SR Research Ltd 89 Example MSG A140340 FV CLEAR 2 5 5 2 50 200 This clears the display to white color 7 3 4 2 Line drawing Identifier DRAWLINE Description This command draws a line with the color specified by the red blue green integer values specified in the command Each RGB value should be an integer between 0 and 255 Format IV DRAWEENE lt red gt lt blucs lt Green gt lt x Start gt sy Stert gt lt x end sy end Note lt x_start gt x coordinate of the starting point lt y_start gt y coordinate of the starting point lt x_end gt x coordinate of the end position lt y_end gt y coordinate of the ending position Example MSG 9441901 V DRAWLINE 255 0 0 100 100 300 400 This draws a red line connecting 100 100 and 300 400 7 3 4 3 Drawing a Rectangle Identifier DRAWBOX Description This command draws a framed rectangle with the color specified by the red blue green integer values specified in the command Each RGB value should be an integer between 0 and 255 Format EyeLink Data Viewer 2002 2008 SR Research Ltd 90 IV DRAWBOX lt red gt lt blue gt lt green gt lt top gt lt left gt lt right gt lt bottom gt Note Left top right and bottom refer to the x y coordinates of the top left and bottom righ
56. Edit Analysis Window Help oljel o B a xean ik Molom Beee Farmar 7 Data Preferences g C Untitled evs picture Trial 1 ED Trial 2 ED Trial 3 E Interest Area Templates 18 x lt gt Fixation Sms T Saccade 472ms TP Fixation 528ms gt Saccade 664ms lt gt Fixation 684ms T Saccade 1128ms TP Fixation 1160ms gt Saccade 1404ms lt gt Fixation 1416ms T Saccade 1668ms TP Fixation 1692ms gt Saccade 1880ms lt gt Fixation 1900ms gt Saccade 2112ms TP Fixation 2148ms gt Saccade 2656ms Label rial 1 Index 1 Recording Fle 62797388 ms 62817622 ms 20234 ms E start EyeLink Data viewer 3 14 PM Figure 4 1 Viewer Display after Loading the Sample Picture edf File 4 1 Inspector Window The Inspector Window consists of 2 tabs the Data Tab and the Preferences Tab see Figure 4 2 4 1 1 Data Tab EyeLink Data Viewer 2002 2008 SR Research Ltd 8 The Data Tab consists of 3 panels Figure 4 2 left Panel The top panel provides a tree view of the viewing session The first level of the tree view contains trial grouping nodes F EyeLink Data Viewer lists trials within a viewing session by either data file or by experimental conditions Each trial grouping node has a set of tree leaves representing the trials that are contained within that node The middle panel represents a list of components that are within the selecte
57. EyeLink Data Viewer User s Manual Document Version 1 8 402 Please report all functionality comments and bugs to support sr research com Copyright 2002 2008 SR Research Ltd EyeLink is a registered trademark of SR Research Ltd Mississauga Canada Table of Contents l Fc 0 10 06 6 8 item er ee ene E nO a oe en S l Il Data Vi vaza Oee E EE EA E A aN l k2 Event se CCO keroki ete eer Re Se aE en eee ee eT eee 2 1 3 TALEFESU ATCA DCL OM smiir e E E 2 ks Event PINON esonera e a 2 1 5 Interest Periods and Reaction Time Definition cc cc cccccccceseeecceeeeeeeeeeeeeeaeees 3 Le Data Output atid Analysis seieren a a a 3 Lee Experiment NISC at ON agi aee e E A T E 4 Dr SAS GAMA ooa E E maa teaie 5 21 Systemi Regue MENS eresian Webern era a e ohudaie betiedan vs nsmutebesadeesocoeea 5 22 DCU i o EEEE A E E EE E E E dunes EE E E E E 5 3 Workin with PINGS erresemias aen n EE A E E E 6 3 1 Creating a Data Viewing Session DVS cccccccccccccceeeeeeeseseeesseeseeeeeeceeeeeess 6 3 2 Opening an Existing Viewing SeSSION ccccccccccccceeeeeccaeeseeeseseseseeeeeeeeeeeeees 6 3 3 Savile a VAS WANG SESSION en iaren eE EEE E E apie EE testers 6 3 4 Saving an Existing Viewing Session to a Different File cccceeeeceeeeeees f 39 lmiportine aw Eye Link Data Pile science leleie a ire ees f T Daa N ew E WW MNOS cated ie E TA OOT 8 4 1 IS POCO WO Wicd cassas chest ncis a A adauaaaeaeaenacnnatuaame nines 8 4 1 1 Dat
58. GE1 START 5686598 BUTTON 5686573 5 true MSG 5686595 DRIFTCORRECT R RIGHT at 320 40 OFFSET 0 09 deg 4 1 1 4 pix MSG 5686597 RECCFG P 500 2 1 MSG 5686597 GAZE COORDS 0 00 0 00 1023 00 767 00 EFIX R 5686602 5686852 252 514 2 388 949 0 50795 BUTTON 5686716 5 false MSG 5686723 DISPLAY ON MSG 5686726 SYNCTIME 3 ESACC 5686854 5686900 48 514 1 385 7 229 0 50 55 44 45 EFIX 5686902 5686980 80 340 2 80 6 false 5 the ESACC 5686982 5687012 32 339 6 84 4 162 0 50 25 43 85 EFIX 5687014 5687176 164 195 0 44 4 false 3 not ESACC 5687178 5687192 16 189 7 41 5 62 0 50 35 43 8 R R R R R R EFIX 5687194 5687364 172 153 8 45 2 false 2 did EyeLink Data Viewer 2002 2008 SR Research Ltd 80 ESACC 5687366 5687384 20 157 9 47 8 232 8 51 9 1 49 116 0 50 3 43 8 EFIX 5687386 5687588 204 233 9 54 8 45 0 50 25 43 8 false 3 not ESACC 5718822 5718836 16 621 3 723 4 677 1 712 5 1 09 96 0 52 35 46 7 EFIX 5718838 5718968 132 684 3 710 4 46 0 52 45 46 7 false 142 sides ESACC 5718970 5719032 64 685 0 706 9 347 0 106 4 14 87 371 0 51 3 45 05 EFIX 5719034 5719336 304 356 5 131 343 0 50 25 43 5 false 16 not BUTTON 5719243 5 true MSG 5719244 ENDBUTTON END 5719345 MSG 5719360 TRIAL OK In this output file the display coordinates and frame rate were reported first followed by information from individual trials This includes the selected fixations saccades blinks messages and button events and excludes any hidde
59. GLOAD TOP LEFT lt relauive i age path gt lt x posilion gt lt y position gt Width height Note width and height are optional parameters Example MSG 2740540 V IMGLOAD TOP LEFT fixations gif 200 200 7 3 3 3 Image Loading Centered EyeLink Data Viewer 2002 2008 SR Research Ltd 88 Identifier CENTER Description This message specifies an image to be used as a segment of the spatial overlay view of a trial within the viewer The image size 1s not changed unless width and height parameters are specified and will be positioned centering on the x y coordinate specified The image should be represented as a relative path The viewer will look for the image in the following order 1 In the default image directory specified in the general preference settings 2 In the directory the EyeLink data file is loaded from 3 In the directory the viewer application is running from Format IV IMGLOAD CENTER lt relatiave amage path X POSICION lt y position gt width height Example MSG 2740540 V IMGLOAD CENTER fixations gif 200 200 7 3 4 Simple Drawing Besides the image loading the viewer also supports a set of commands that draws simple graphics such as lines framed box filled box as well as display clearing 7 3 4 1 Clear Overlay View Identifier CLEAR Description This command clears the overlay view to the color specified by the red blue green integer values specified in the command
60. IAL VAR LABELS Description This message allows the definition of the labels to be used for trial variables within the viewer The command identifier can be changed in the data loading preference settings Format TRIAL VAR LABELS lt trial variable list gt EyeLink Data Viewer 2002 2008 SR Research Ltd 84 Example MSG 3363553 TRIAL VAR LABELS TRIAL VAR 1 TRIAL VAR 2 TRIAL VAR 3 7 2 2 Display Coordinates Identifier DISPLAY COORDS or GAZE COORDS Description This message specifies the display coordinates to be used within the viewer This message MUST be present for the viewer to function correctly Format DISPLAY COORDS lt left gt lt top gt lt right gt lt bottom gt Left top right and bottom refer to the x y coordinates of the top left and bottom right corners of display Example MSG JOLO AL DISPLAY COORDS 30 0 279 02S 7 2 3 Trial Grouping Identifier V TRIAL GROUPING Description Trial grouping message is used to group those trials in the same experimental condition together so that they can be manipulated e g selecting hiding deleting applying interest area templates collectively This message must be sent after TRIAL VAR LABELS message but before first trial start message in EDF file Format V TRIAL GROUPING lt trial variable list gt The trial grouping variable s must be a member of the variables listed in the TRIAL VAR LABELS otherwise this variable is simply ignored Example
61. LOCITY to which the message 1s associated CURRENT MSG SAC START TI Start time relative to the start of the interest ME period of the saccade to which the message is associated which the message 1s associated which the message 1s associated period of the message CURRENT MSG X POSITION X position of the current message text It may be a missing value if samples are not loaded in the viewing session CURRENT MSG Y POSITION Y position of the current message text It may be a missing value if samples are not loaded in the viewing session DATA FILE File name of the recording EYE USED Which eye s data LEFT or RIGHT is used to create this report IP DURATION Duration of the interest period in milliseconds IP END TIME End time in milliseconds since EyeLink tracker was activated of the interest period IP LABEL Label of the current interest period selected in the viewing session IP START TIME Start time in milliseconds since EyeLink tracker was activated of the interest period TRIAL LABEL Label of the trial TRIAL START TIME The start time in milliseconds since EyeLink tracker was activated of the trial Note Messages written in the EDF file will be associated with an event closest in time In very rare cases the message can be written to both saccade and fixation events if the message was written out after the last sample of a fixation or saccade but before the first sample of the following saccade or fix
62. MSG BLINK END End time relative to the start of the interest period of the blink to which the message 1s EyeLink Data Viewer 2002 2008 SR Research Ltd 77 of associated CURRENT MSG BLINK INDEX _ Index of the blink to which the message is associated CURRENT MSG BLINK START Start time relative to the start of the interest period of the blink during which the message was written CURRENT MSG FIX DURATION Duration of the fixation to which the message is associated CURRENT MSG FIX END End time relative to the start of the interest period of the fixation to which the message 1s associated associated CURRENT MSG FIX START Start time relative to the start of the interest period of the fixation to which the message is associated is associated is associated a reaction time definition a reaction time definition CURRENT MSG LABEL Label of the current message event CURRENT MSG SAC AMPLITU Amplitude in degrees of visual angle of the saccade to which the message is associated OCITY saccade to which the message is associated N associated CURRENT MSG SAC END TIME End time relative to the start of the interest period of the saccade to which the message is associated which the message is associated which the message 1s associated associated EyeLink Data Viewer 2002 2008 SR Research Ltd 78 CURRENT MSG SAC PEAK VE Peak velocity in degrees second of the saccade
63. Managing Reaction time Gefinitions cccccccccccceeceeeeesssesseeeeeeeeeeeeees 116 8 3 4 Manipulate E venis sc cat cartrisainead tawsnenciaenitetnncmienaceie ele diee NER 118 Boe CIOS VOT S hat diced teh fee ect itadln a Meda E 118 8 3 4 2 Merging and Drift correcting Fixations ccccccccccccsscsssseeeeeeeeeeees 119 EyeLink Data Viewer 2002 2008 SR Research Ltd v 8 3 5 PAV is 15 CUI AE AEE E A E teed asec aunt E todas 120 Sod IE PIAIOUU PUT TS OM ersa a cies etna tendency a 120 SoL FIXalON OUIPUL TEPO crer A A 122 SA RSP CROCS ciste a e araniehodudtidcobe numebes 125 O Peene SeN S a 127 9 1 GCG Fal Pror hee CS anere E E E O R 128 92 Data Lodde Prerercn Ces roroi oton a E E ET 129 9 3 Obi 0 0 oy ANAI YS Keener aan ener T dine et ee ge erent acre Me ner eee neem 131 OF Data Piller Prcreren Css sta ics cauvsciocnevesdetianiesdisitacdicngudesurve denies EE 133 9 5 General Trial View Preverei Ce Siaxisivscicutoneenns coavnzotvaenasareavascivagaassuaaeagouiagneras 135 9 6 Spatial Overlay View Preferences ci cisacinatetusadiecsdestadoiniddacdcdsesadsiurediecadectadonies 137 9 7 Image Segmentation Preference neseserai i a a E 139 9 8 Temporal Graph Pre Lorene es niione a Sac sciadessctotsted E 140 99 Anmann PEC LCCC CS scaacecl oss ceenanGaty nme E nal tia eanentenameccen 142 List of Figures Figure 4 1 Viewer Display after Loading the Sample Picture edf File 0 0 eee 8 Figure 4 2 Components of the Inspector Window Left
64. S CONDITION The following messages and commands have been added to the w32_control_trial c file of the Control template Data Viewer Functionality Message Commands Trial Variable Values eyemsg printf V TRIAL VAR DATA GAZECTRL eyemsg_ printf V IMGLOAD FILL images grid png eyemsg printf V AREA FILE segments grid 1as 7 5 7 Dynamic Template EyeLink Data Viewer 2002 2008 SR Research Ltd 102 One important feature introduced in the Dynamic template 1s the addition of custom reaction time definition V V_CRT for the saccade trials Reaction time is defined as the interval between the onset of the target SYNCTIME message and the occurrence of the first saccade with a minimum amplitude of 2 0 that falls within 50 pixels from the saccade target goal x goal y The following table lists all of the messages and commands that have been added in the w32 data _trials c file of the Dynamic template Data Viewer Functionality Message Commands eyemsg printf TRIAL VAR LABELS TRIAL TYPE DIRECTION eyemsg printf V TRIAL VAR DATA d s s num trial labels O num 1 trial_labels 1 num 1 Reaction Time Definitions 0 Trials 3 8 eyemsg printf V V CRT SACCADE SYNCTIME 2 0 d d 50 goal x goal y 7 5 8 Comm_simple Template Similar to the Simple template TRIAL VAR LABELS and TRIAL VAR DATA commands were added to the w32 simple t
65. _data_trials c file of the EyeData template Data Viewer Functionality Message Commands Trial Variable Labels eyemsg printf TRIAL VAR LABELS CONDITION Trial Variable Values eyemsg printf V TRIAL VAR DATA Playback eyemsg printf V IMGLOAD FILL images grid png eyemsg printf V AREA FILE segments grid ias EyeLink Data Viewer 2002 2008 SR Research Ltd 101 7 5 5 GCWindow Template The following table lists all of the changes made to the w32_ gcwindow trials c file of the GCWindow template Data Viewer Functionality Message Commands Trial Variable Labels eyemsg printf TRIAL VAR LABELS TYPE CENTRAL PERIPHERAL Trial Variable Values eyemsg printf V TRIAL VAR DATA TEXT TEXT MASK eyemsg printf V TRIAL VAR DATA TEXT MASK TEXT eyemsg printf V TRIAL VAR DATA IMAGE IMAGE MASK eyemsg printf V TRIAL VAR DATA IMAGE MASK IMAGE eyemsg printf V TRIAL VAR DATA IMAGE IMAGE BLURRED Images o o OSO Trials 1 amp 2 eyemsg printf V IMGLOAD FILL images text png Trials 3 4 amp 5 eyemsg_printf V IMGLOAD FILL images sacrmeto jpg Interest Areas Trials 1 amp 2 eyemsg printf V IAREA FILE segments text ias 7 5 6 Control Template The following messages and commands have been added to the w32_control_trials c file of the Control template Data Viewer Functionality Message Commands Trial Variable Labels eyemsg printf TRIAL VAR LABEL
66. a Tas sae nn tesco Pae ee vancatamncns getdate T eacieemikcate rae teresa 8 AA hel Data Tree Hie tat CHYy vi csccicodstancdesav sonst a a a a E 10 MND Wa COU Pll Oo satesius teeu sca a easmueuecetutets 10 elias UTA UMN AL ys eacoch cats a nedareecesuauceoreasteceeteateharedes 11 4A Mterest Area Templates acts tesaccGuciasstawdt astaniansar E 12 4 1 1 5 Custom Interest Area Set Empty Interest Area Set eee 13 4 1 2 PrelerenGes VAD at sfashacwsscaumesstdsdeavowetwnseosuacaviounnesebadesuoreGnuaveinteandiecennesdias 13 A2 PA ACW WV COW es a a a 13 4 2 1 Selecting Data Elements to Display ccccceeeecccceetseeeeesssseseeees 13 42 2 Toni AT a V1 Wyse san re a a T E 14 4 2 3 Tine Cas Cacti Window Seasca Oi tctc telnet tesibaande desc vedvauthe 14 4 3 Spatial Overlay Trial Vi Whats acedchantat lent snaded dacateomeaaiieleantattonisuiand daenenetes 15 4 4 Temporal Orap 1 tial VIEW ascorn T EE 17 4 4 1 Viewing Sample and Target Data seieren ea E A i 17 4 4 2 ZOOMING OCCT AUONS iieri aucnereanteeldrmecketoes 19 4 5 TTI COTE NV 16 Veenre ees teadten ou aha oat enemy Sch eencer ee eae 19 5 Working with Events Samples and Interest Areas cccccccsceeeccceeeeeeeeeeeeeeaeees 21 5 1 Common Operations ariere rone enaa Ree siew nae raa E AEO EOE A EEANN EONS 21 Sl Selec E VER Soora a dae peneaencaaunieentacnneaylteackens 21 51 2 Deleting EVENS secre a E EE EE 21 Ie ERAO eae r os ng nd da eases lee execs 22 5 221
67. ables for Eye Event set in the Output Analysis Preference Settings CURRENT FIX MSG TEXT Text string for messages associated with the current fixation CURRENT FIX MSG TIME Trial time of the message CURRENT FIX NEAREST Nearest interest area the current fixation 1s EyeLink Data Viewer 2002 2008 SR Research Ltd 60 _INTEREST_AREA CURRENT FIX NEAREST Distance between the current fixation point and the _INTEREST AREA DISTANCE _ center of the nearest interest area the current fixation 1s associated with INTEREST AREA LABEL fixation 1s associated with CURRENT FIX REFIX INTERE Whether this trial has a previous fixation in a different run that had the same interest area as the current fixation If so the CURRENT FIX INDEX value of the very first fixation in that interest area is given CURRENT FIX REFIX PREV I Whether this trial has a previous fixation in an JA NTEREST AREA with higher IA ID than current fix IA ID see run definition CURRENT FIX RUN DWELL T Total amount of dwell time in msec in the current IME run of fixations CURRENT FIX RUN INDEX Ordinal sequence of the current fixation in the current run of fixations The first fixation in this run has a RUN_ INDEX of 1 and the second one has RUN INDEX value of 2 and so on Trial time when the current fixation starts on the other eye in a binocular recording CURRENT FIX TRIAL SPAN Whether the fixation starts before the trial starts a
68. actice trials for each possible combination of target presence target present vs target absent set size 6 12 or 24 items in a display feature number of features shared between the search target and distractors one feature vs two features by calling the create display function The save _ display info function is used to save the interest area information into EyeLink Data Viewer 2002 2008 SR Research Ltd 104 a ias file Note that the eyelink_exptkit20 lib file must be included in the project to ensure the program running appropriately 8 2 2 Generating Randomization Files The Gen_Rnd project is used to generate randomization script files for individual subjects The main function takes two arguments passing the subject id and discriminability information to the create _rnd_file function The latter function translates a sequence of random numbers generated by sequence into trial condition information target presence set size and stimulus number and records it into a text rnd file 8 2 3 Programming the Visual Search Experiment The current experiment is modified after the Picture template Therefore reading the description of the first three templates Simple Text and Picture of the Programming EyeLink Experiments in Windows Version 2 0 manual will be helpful in understanding the source code of the current experiment 8 2 3 1 Source Files for VisualSearch The following table lists all
69. aetna eet S 102 TES Dynami Lemplil eesriie T A E 102 7 5 8 SCOM Simple Lempit senei n lvoe teas otetonct essere 103 7 5 9 Other Template Sieisen E euch veeseetecsmaatea ean uated 103 BS OTA Visual Scare ema cepacia roads en Saeco GEE 104 8 1 Project Back round TniorimaniOn sereni E a ieee 104 S2 PIOS a oer a o E E E E TRE 104 8 2 1 Creatine Interest Area Set EIOS iaiu A 104 S22 Generating Randomization FileSend E 105 8 2 3 Programming the Visual Search Experiment ccceessesssseeeeeeeeeens 105 8 2 00 source Biles for Visual Scan aise civavicsmiecainetavei deere 105 Saa WSP Mia IOs ti hans ct xa tinammeb eect Aaennciexntnee ee ese ee 106 Sa WIZ SCPE AlS C a nea E EE 106 8 2 4 Adding Data Viewer Functionalities ccccccccccccsccssssssssssesseeeeceeeeeees 106 B24 tal Aria Wea DCIS an T T 107 S242 Wirral aiid al soit dicts ae autecataenses a E eaten 107 Bee Mla hs MUA eee esa tata aa ae ae es eee 108 SALAA TETS ATE ee eae A SO ra eoludiandbesentbavs 109 8 3 Da PVA SS ana a a A sia aaeneeaeedea tener 109 8 3 1 Viewing session Manipulation and Data Loading ccccceeceeeeees 109 8 3 2 Triar Mami pula On i jasssssceavieacioncsasvteaviteaue avianvidetviaenesviaeiccateendbanieesecaiones 111 Saal Lodin Tak BMA Preno n N 112 3 22 Loading Trial Interest Area Selaccssesicavsccceuereseids ain EE 112 8 3 2 3 Manipulating Trial Condition Variables 2 0 0 0 cceseseeessseeeeeeeeeeeees 113 8 3 3
70. al such as the title to be displayed at the bottom of the eyetracker display trial conditions and bitmap etc The do script trial function is used to execute each individual trial The next section highlights all of the important messages and commands to be included in the EDF file to support the Viewer analysis 8 2 4 Adding Data Viewer Functionalities The current section lists all of the commands and messages that are important for the EyeLink Data Viewer analysis All of these messages and commands are added in the EyeLink Data Viewer 2002 2008 SR Research Ltd 106 w32_script_trials c file of the VisualSearch template Reading the previous chapter of the current manual section 7 Protocol for EyeLink Data to Viewer Integration will be very helpful 8 2 4 1 Trial Variable Labels The TRIAL VAR LABELS message included in the run_script_trials function allows the definition of the labels to be used for trial variables within the Viewer program This message must be sent to the EyeLink data file prior to the first trial start message such as TRIALID TRIAL VAR DATA etc TRIAL VAR LABELS message is recorded for EyeLink Data Viewer analysis It specifies the list of trial variables for the trial This should be written once only and put before the recording of individual trials eyemsg printf TRIAL VAR LABELS TRIAL FILENAME PRACTICE DISCRIMINABILITY FEATURES PRESENCE SETSIZE 8 2 4 2 Trial ID and T
71. al Variable Message Token EyeLink Data Viewer 2002 2008 SR Research Ltd 86 Identifier Default TRIAL VAR Description This command lets the user specify a trial variable and value for the given trial Send one message for each pair of trial condition variable and its corresponding value This means that there is really no need to use TRIAL VAR LABELS command when using this command The default command identifier can be changed in the data loading preference settings Please note that the eye tracker can handle about 20 messages every 10 milliseconds So be careful not to send messages too quickly when you have many trial condition messages to send Add one millisecond delay between message lines if this 1s the case Format Iv TRIAL VAR lt trial var label gt lt trial var value lt trial_var_label gt is the label for the variable being set If the current Data Viewer session does not have this variable yet it is created lt trial var value gt defines the value to set for the variable for the given trial Example MSG 9350338 V TRIAL VAR trial 1 MSG 9300339 1V TRIAL VAR Condici0n gap MSG 9350340 V TRIAL VAR direction Left MSG 9350341 V TRIAL VAR gap duration 200 MSG 9350342 V TRIAL VAR t_x 212 MSG 9350343 V TRIAL VAR t y 384 7 3 3 Image Commands The viewer supports a set of commands that display a default image on the overlay mode of the trial viewer screen All image commands use the IMGLOAD token followed by a
72. ariables 6 6 Fixation Report Fixation report creates a columnar output of fixation events Each row of the report represents a fixation event Depending on the variables selected for output each row can contain information on the previous fixation and or saccade as well as the next fixation and or saccade 6 6 1 Obtaining a Fixation Report To obtain a fixation report follow the same procedure as in obtaining the trial report except from the menus choose Analysis Report Fixation Report 6 6 2 Variables in the Fixation Report Currently the fixation report includes the following variables RECORDING SESSION LABEL Label of the data file CURRENT FIX ADJUSTED Whether the current fixation has been adjusted manually CURRENT FIX BLINK Whether there is a blink preceding or following the AROUND current fixation Possible values are AFTER a blink follows the current fixation BEFORE a blink precedes the current fixation BOTH the current fixation is flanked by a preceding and a following blink or NONE no blink appears around the current fixation CURRENT FIX BUTTON 0 PR Time from trial start if a specific button 0 8 has ESS been pressed during or after fixation If no button jas press is made from the start of the current fixation CURRENT FIX BUTTON 8 PR to the start of next fixation missing value 1s ESS assigned CURRENT FIX DURATION Duration of the current fixation Ey
73. as activated Timestamp when the trial recording ended in milliseconds since EyeLink tracker was activated Duration in milliseconds of the trial recording Reaction Time Configurable response time determined by the Reaction Time Definition associated with the trial Use the value of Duration if RT is undefined RT Event Index Index of event that triggered the end of the reaction time 1 when NO MATCH The index is relative to a specific event type for example an index of 5 for a Saccadic RT means the 5 saccade in the trial RT Event Type The way in which the trial reaction time is ended possible values are TIMEOUT BUTTON FIXATION SACCADE MESSAGE or NO MATCH RT Definition Label Label of the reaction time definition see section 6 3 1 Ge 99 Managing Reaction Time Definitions 1f undefined CUSTOM if the RT definition is a custom one see Section EyeLink Data Viewer 2002 2008 SR Research Ltd 11 LO 7 4 Reaction Time Definitions Average Fixation Average duration in milliseconds of all fixations in the trial duration Average Saccadic Average size in degrees of visual angle of the saccades in Amplitude the trial Report Hidden Whether or not to hide the trial from output reports Interest Area Set Setting of the interest areas Custom Interest Area Set or Empty Interest Area Set If interest areas have been defined they can be removed by selecting Empty Interest Area Set
74. ase note that when using this option the interest period end message must be different from the start message otherwise the user should use a duration based interest period instead see below Duration Based The interest period can also be based on a duration following the detection of the start message e g 10 seconds following the SYNCTIME message The user needs to specify a message string case sensitive DO NOT include quotes for text strings in the Start Time Message Text edit box The user can also specify an optional offset time value so that the interest period does not start right on the message time In the Duration edit box enter the desired duration a positive number in milliseconds of the interest period 4 Close the Interest Period Editor dialog This will initialize the interest period for all trials 6 4 2 Using Interest Period The newly created interest periods are added to the interest period list along with the default interest periods Full Trial Period and Reaction Time Period The user can navigate between different interest periods by selecting the desired interest period from the list For each interest period only those events falling within that period are shown in the spatial overlay temporal graph views and in the event list of the inspector window In addition for all of the following output analyses trial fixation saccade interest and recording sequence outputs only
75. ata To view trial data in this mode select the button in the top left corner of the Trial View Window a Trial iew BINOZTARG Trial 1 2 O x rotse x y fraver x yt 10682 11504 2325 13147 13969 14791 1501 Figure 4 5 Sample Temporal Graph Trial View 4 4 1 Viewing Sample and Target Data Time plot view will show trace plots only if the EDF file contains samples and if sample are activated for viewing 1 e the Toggle Eye Sample Visibility button amp on the Data EyeLink Data Viewer 2002 2008 SR Research Ltd 17 Viewer tool bar is selected The position velocity and acceleration sample traces can be selected for viewing from buttons within the Trial Viewer Window View Trial Spatially with Image Overlay Select the spatial overlay mode a Acceleration Trace Shows the gaze or target acceleration data Save Trial View as Image Creates an image of the temporal graph view Changes from the previous versions to show the eye or target traces in this version the user needs to select the type of data position velocity or acceleration and data source x y pupil of left eye and or right eye x y of target and or target2 to be shown To show the position velocity and acceleration traces of target s in this view messages on the current position of the target s must be recorded in the EDF file These messages should contain a target position keyword V TARGET POS by defau
76. ation In addition other user defined trial variable labels will also be listed Please note that the data output in the message report depends on the setting of the interest period filter see section 6 4 2 or Figure 6 13 only those events falling within the active interest period will be reported Ifa valid reaction time definition is found in a trial the EyeLink Data Viewer 2002 2008 SR Research Ltd 79 TRIAL START TIME will be set as the start as the reaction time definition otherwise this will be set as the start of trial recording see section 6 5 3 on discussion of three time periods used in Data Viewer 6 11 Recording Event Sequence Data Recording Event Sequence Data 1s a trimmed version of the EyeLink ASC file For each trial it outputs the selected events only and excludes the hidden events 6 11 1 Obtaining a Recording Event Sequence Data To obtain a recording event sequence data report 1 From the menus choose Analysis Report gt Recording Event Sequence Data 2 In the Export dialog box browse to the directory in which you want to save the data 3 In the File name text box type in the name for the data 4 Press Export button 6 11 2 Formats of the Recording Event Sequence Data The following output is a trimmed version of a sample recording event sequence report MSG 5520005 DISPLAY COORDS 0 0 1023 767 MSG 5520005 FRAMERATE 85 05 Hz MSG 5520009 TRIAL VAR LABELS PAGE MSG 5684435 TRIALID PA
77. ation in JA regardless of TION run IA SECOND FIXATION RUN Index of run that the second fixation 1s 1n TA SECOND FIXATION TIME Time of the second fixation in IA regardless of run IA SECOND RUN DWELL TIM Dwell time 1 e summation of the duration across all fixations of the second run of fixations within the current interest area TA SECOND RUN END TIME End time of the second run of fixations in the current interest area IA SECOND RUN FIXATION Percentage of all fixations in a trial falling in the EyeLink Data Viewer 2002 2008 SR Research Ltd 68 COUNT second run in the current interest area ME current interest area IA SELECTIVE REGRESSION Duration of fixations and refixations of the current interest area before the eyes enter an interest area with a higher ID IA SKIP An interest area is considered skipped 1 e IA SKIP 1 if no fixation occurred in first pass reading IA SPILLOVER The duration of the first fixation made on interest area N 1 after leaving interest area N in first pass ON run IA THIRD FIXATION RUN Index of run that the third fixation is in TA THIRD FIXATION TIME Time of the third fixation in IA regardless of run IA THIRD RUN DWELL TIME Dwell time 1 e summation of the duration across all fixations of the third run of fixations within the PATH DURATION current interest area interest area third run of the current interest area current
78. bel edit box and select the type of interest period end event Button Message or Duration based from the Type combo box EyeLink Data Viewer 2002 2008 SR Research Ltd 51 o EyeLink Data iewer File Edit Analysis Window Help dolelsjala x alajajajsik Moom Mellel eH frrr o Inspector IIz j Trial View text Trial 2 Data gf Preterences Se 4a au Untitled evs cl _ The house was ap about th gh i e spre ing lawns under interlacing _ aboutthrough wide spreading lawns and under the inter Bough oftl poplars At the rear tings were on oven amore LP Fixation 1962ms Fixation 2142ms TP Fixation 2338ms P Fixation 2542ms gt Fixation 2642ms LP Fixation 3130ms Fixation 3466ms Fixation S3690ms gt Fixation 3930ms gt Fixation 4270ms LP Fixation 4546ms P Fixation 4634ms TP Fixation 5178rms TP Fixation 5346rms SP Fixation 5622ms 40 Fixa 5942ms 23 long grape o Interest Period Editor General Details rl ll Label New Interest Period 01 Type Button Event Button Event Message Event Duration Based tion There could not but be other dogs Avg X Position 431 8 Avg Y Position 217 0 Figure 6 10 Interest Period Editor General Tab vl 3 Select the Details Tab see Figure 6 11 23 Interest Period Editor
79. characters the file name is appended with a txt by default Press Export button EyeLink Data Viewer 2002 2008 SR Research Ltd 54 as Output Report x Available Output Variables selected Output Variables JAVERAGE FRAATION DURATION AVERAGE SACCADE AMPLITUDE AVERAGE X RESOLUTION AVERAGE RESOLUTION BUNK COUNT BUTTON PRESS COUNT ee DATA FILE lt lt DURATION ENO TIME FRATON COUNT INDEX AVERAGE X RESOLUTION Definition Average horizontal angular resolution in screen pixels per degree for the trial RECORDING SESSION LABEL Exclude Trial Strin Place Quotes Around String Text Variables Reset Cancel Next Figure 6 12 Selecting Output Variables in a Trial Report 6 5 2 Variables in the Trial Report The following variables are listed in the trial report Field RECORDING SESSION LABEL Label of the data file DURATION fixations in the trial AMPLITUDE selected saccades in the trial screen pixels per degree for the trial BLINK COUNT Total number of blinks in the trial BUTTON PRESS COUNT Total number of button presses in the trial DATA FILE DURATION Duration of the trial recording between the START message and the END message END TIME Timestamp when the trial recording ends in milliseconds since EyeLink tracker was activated EyeLink Data Viewer 2002 2008 SR Research Ltd 55 EYE USED Which eye s data LEFT or RIGHT
80. ction time definitions the above messages must be recorded within the scope of trial as defined for the Viewer see section 7 1 A third approach as illustrated in the current tutorial is to create a set of condition based reaction time definitions manually see section 6 3 To manually create new RT definitions or to review edit existing RT definitions click Analysis Reaction Time manager from the application menu see Figure 8 9 In the following reaction time EyeLink Data Viewer 2002 2008 SR Research Ltd 116 manager dialog click on the New RT Definition button In the Reaction Time Definition Editor dialog General Tab enter the label RT Absent In the trial condition qualifiers list select the variable PRESENCE and type in Absent case sensitive without quotation marks in the value edit box and press the Enter key Since participants pressed a specific button to end a trial keep the default Button Event as the reaction time end event e EyeLink Data Yiewer O x File Edit Analysis Window Help olololela x g Inspector E Cl x Data Preferences E HD_RCN AT Trial 2 AT Trial 3 o Trial 4 AT Trial 5 AT Trial 6 AT Trial 7 g Trial 8 lt gt Fixation 316ms LP Fixation 464ms lt gt Fixation 956ms e Reaction Time Definition Editor lt gt Fixation 1156ms lt gt Fixation 1304ms TP Fixation 1532ms LP Fixation 1688ms lt gt F
81. d Time Plat will not have an effect if Fill Gaps Between i Animation IA is checked Fill Gaps Between IA If checked gaps between consecutive Interest Areas will be filled by Segmentation Spacing expanding the size of each Interest Area Top IA Buffer Size 0 O O OZO Background Threshold 0 765 Combined RGB R G B to be used as the threshold limit for Fil Gaps Between tA A seam Background Threshold Background Threshold Less Than If checked pixels with a RGB value less than the threshold color are considered background pixels This setting is good for displays with a lighter background If this field 1s unchecked pixels with an RGB value greater than the threshold are considered background pixels good for displays with a darker background Note Auto segmentation may not work for a display with vertical stripes along its border s that have the foreground color If such stripes are not part of the original image try to reload the background image or to change the background color for the spatial overlay view to match with the background color of the original image EyeLink Data Viewer 2002 2008 SR Research Ltd 139 9 8 Temporal Graph Preferences The parameters related to the temporal graph view preference settings are covered below m Preferences General oe Data Loading oe Output Analysis e Data Fitters EH Data Views 1 I Overlay e ami
82. d commands that can be sent to the EDF file to enable the EyeLink Data Viewer to extract information in a more efficient way The current section provides an overview of the changes made in the sample experiment templates Please refer to the Programming EyeLink Experiments in Windows Version 2 0 manual for the description of individual templates 7 5 1 Simple Template Two EyeLink Data Viewer commands have been introduced in the Simple template TRIAL VAR LABELS for the definition of the labels to be used for trial condition variables within the viewer and TRIAL VAR DATA for the assignment of condition values for each trial All these changes listed in the following table were made in the w32_ simple _trials c file of the template Data Viewer Functionality Message Commands Trial Variable Labels eyemsg printf TRIAL VAR LABELS TRIAL WORD Trial Variable Values eyemsg printf V TRIAL VAR DATA s trial word num 1 7 5 2 Text Template Along with the TRIAL VAR LABELS and TRIAL VAR DATA commands the Text template also uses IMGLOAD FILL to load a single image and IAREA FILE to import a file containing interest areas for the trial All of these changes listed in the following table were made in the w32 text trials c file of the template Data Viewer Functionality Message Commands EyeLink Data Viewer 2002 2008 SR Research Ltd 100 Trial Variable Labels ey
83. d node of the analyses session tree If a trial is selected in the viewing session tree a list of visible events is displayed If an Interest Area Set is selected a list of interest areas that make up the set are selected The bottom panel is a table representing the properties of the selected tree node or selected list component For example if a fixation 1s selected all properties of the fixation are listed in the properties table Some properties like color are editable by pressing on the property value with the mouse Data Tab Preference Tab F TE Data wh Preferences Preferences picture sane General AT ET Trial 1 Trial Mode AM Data Loading Trial E Trial 2 H Output f Analysis Grouping ED Trial 3 fj Data Filters ye LA Set ao E Treeview fb be Ho Custom Interest 4rea Set gt gt e Image Segmentation ED Trial 2 sod Tine Plot Trial 3 si Animation i TEN ILA Template EG Trial 4 Interest Area Templates eo Empty Interest 4rea Set ee E E l EE Fixation Sample Trace Color Event List gt Fixation E 40 Fixation 630ms Display Fixation Index ED Fixation 882ms Display Fixation Dur fw E Fixation 10 amp 6ms Display Saccade Index fw Display Fixations as ization 630ms 7 Start Time ea0ms ample Trace Grand 5 Properties gt pamela ie need Paea panne i Avg Position 115 4 0 3 Minimum TA Size Avg Position EyeLink Da
84. dainarhtadeeatd ET 33 Figure 5 9 Sample Spatial Overlay View left and Temporal Graph View right of Way UNG ND e PA E E A E T E A T T 34 Figure 5 10 Sample Text Display Overlaid with Interest Areas 00000nennnnnnnnnnnnsssses 35 Figure 5 11 Creatine a Freehand Interest Atearcicaisad aninierin ashe aa 37 Figure 6 1 Trial Variable Manager cccccsssssseseeessseeseseeseeeeeeeeeeeeeeeeeeeeeeeeeeseeeeeees 43 Figure 6 2 Trial Variable Value Editor Dialog ccccccccccceceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 44 Figure 6 3 Applying Trial Grouping by a Trial Condition Variable and Setting Interest Area Template for a Group of Trials cccccccccccsssssssssssssseeeeeeeceeeeeeeessaaeeeeesseseeees 45 Figure oA Sample Fix aliOm Ma Perisa N ges 46 Figure 6 5 Reaction Time Definition Manager cccccseeeesseseeseeeeseeeeeeeeeeeeeeeeeeeeees 47 Figure 6 6 Reaction Time Definition Editor General Tab 00000soonneennneneennsnssssssssee 48 EyeLink Data Viewer 2002 2008 SR Research Ltd vi Figure 6 7 Reaction Time Definition Editor Reaction Time Tab cecceeeeeeeees 48 Figure 6 8 Deleting Reaction Time Definitions cccccesessseeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 50 Figure 6 9 Reaction Time Graphics in Both the Spatial Overlay View and the Temporal Graph View of the Trial View WindOw scsisesssvwcadseaxsistcsarddacensusatssavecccscednsetasevededeess 50 Figure 6 10 Interest Per
85. de variables beginning with PREVIOUS SAC tracker was activated of the trial VIDEO FRAME INDEX START Index of the video frame that was visible at the start of the eye event Note that all VIDEO variables are applicable to SceneLink recordings or some Experiment Builder recordings only For SceneLink recordings please check out the Data Loading Preference Settings of the eye event start of the eye event end of the eye event In addition to these default variables other user defined variables are also listed 1f they have been defined in the EDF file see section 7 2 1 on creating trial variable labels or created during the viewing session see section 6 1 1 on trial variable manager Please note that the data output in the fixation report depends on the setting of interest period filter see section 6 4 2 or Figure 6 13 only those fixation and saccade events falling within the active interest period will be reported If the Trimmed Spanned Fixation Duration setting of the Data Filter preference is enabled the duration start time and end time of the fixations that overlap with the start or end of the interest period EyeLink Data Viewer 2002 2008 SR Research Ltd 63 will be adjusted accordingly If a valid reaction time definition is found in a trial the TRIAL START TIME will be set as the start as the reaction time definition otherwise this will be set as the start of trial recording see section 6
86. de Trials with Use Nearest Interes 7 Auto Select Interest 7 Fixation Saccade Maximum Message Eye Event Mag Yar Fixation Map M Hest Map Mode B Sigma cin degrees Fixation Stream An Fixation Skip Count Output Reports Variable Delimiter t for Tab Specifies the delimiter string for separating columns in the output file Missing Value Replaces variables with missing value with a string specified here Decimal Places Specifies the number of digits to appear after the decimal point Include Hidden Events in Relative Variables Allows the inclusion of hidden events in the relative event variables 1 e those variables beginning with PREVIOUS FIX NEXT FIX PREVIOUS SAC or NEXT SAC Treat Hidden Events as Missing Values If hidden events in the relative variables are included in the analysis the user can further decide whether or not to treat these events as missing data Bracket Strings with Quotes Adds a pair of quotation marks for string variables Exclude Trials with Message String Excludes trials containing the specified message string This string should be one message or part of a message within the scope of a trial that uniquely defines that subset of trials to be excluded Auto Select IAS for Trial If true trial interest area set association 1s done automatically by using Image Name mapping attribute of interest area set
87. ding of samples fixations saccades blinks messages and buttons from the EDF files By default all of the events are loaded whereas samples are not Note Versions before 1 7 1 loads samples as well by default Trial Load Start Message and Trial Load End Message Define the start and end messages of data loading For each trial all events samples before the start message or after the end message will not be loaded By default the Viewer treats the TRIALID as the start message for data loading and TRIAL RESULT as the end message Note the Trial Load Start Message must be one message before START recording otherwise the Viewer will internally re set the loading position at the start of trial recording to keep trial data integrity All Trial Variable Labels Message and All Trial Variable Values Message The former allows the definition of labels to be used for trial variables within the viewer and the latter specifies the list of trial variable values for the trial By default the trial variable labels message is set as TRIAL VAR LABELS and the trial variable values message is set as TRIAL VAR DATA Single Trial Variable Message This command lets the user specify a trial variable and value for the given trial Send one message for each pair of trial condition variable EyeLink Data Viewer 2002 2008 SR Research Ltd 129 and its corresponding value This means that there is really no need to use TRI
88. e eS 39 5 8 8 Automatic Trial Image Interest Area Set Association 39 5 8 9 Deleting Interest Area Tl crimplates cit ain tceoaige dca a 40 5 8 10 Selecting Merest ACIS arri o ones T O S dct 40 511 Moving an Interest ATCA ancse E A TEE 41 5 8 12 Resizing Rectangular and Elliptic Interest Areas ccccccceeeeeeeeeeeees 4 5 8 13 Resizing Freehand Interest Areas 2 0 0 0 cccccccccceccssseeeeessssssseseeeeeeeeeeeees 42 SSAA Deleune Interest Areas enana eh wee 42 SOY DOMES IMLEESt AT CAS oaa eevee uae O 42 5 8 16 Merging Interest Areas ccccssssssssssssesseeeeececcceeeeeeessaeeceesssssseeeeeeeeeeees 42 Expor 020g O21 2 mn ert lee ee ie re se eee eee ee nr eee 43 6 1 Manaeing Birial Variables s 25scixe ots oledasksouscod tte eiirn arineleuiencedcol ada ane 43 6 1 1 Diva Var tA VG IN At AC eiia caesar so ddicei eis EE 43 6 1 2 Trial V atianle Value Editor osvsacsesitna aay eiea se ee ease aes 44 6 1 3 Tal Gr Ou ping has t neues on aaa aoceuti teense undue N 44 6 2 PEX AU OM Mapesa n asad xansonmonseasdeconddecseseasdehadsommonieandeses 46 6 3 Managing Reaction Time DofiMmitionSsirsiecris e E 46 6 3 1 Reaction Mime Manager aeure a T TET 47 6 3 2 Viewing Reaction Time Information cccccccccccccccssssesssssseseeeeeeeeeeeeees 50 Ge MELSE e a a a ee a ees 50 6 4 1 Creatine Interest PCOS sernesta nE AEAEE EEEE 51 6 4 2 Ws ine neres t Pood oaii A A 53 6 5 TaN R epo nea a a 53 6 5 1 Obtaining 2a Trial REDO cenione rne
89. e fields that are editable in the viewer are marked with an asterisk Label of the message Time Trial time when the message was presented Note that if the message 1s presented before the trial starts a negative time value will be displayed Command If the message is a command message this lists the actual command used The commands include simple drawing built in audio messages interest area commands etc Message text Concurrent gaze coordinates when the message 1s recorded EyeLink Data Viewer 2002 2008 SR Research Ltd 30 ee 100 if no gaze information was available for the time of the message event see reaction time definitions Whether the current message is hidden from viewing Color To achieve better visibility the color of the currently selected message can be changed by clicking on the color toolbox a EyeLink Data iewer Oj x File Edit Analysis Window Help Dejes elajas Moom eleien mmr P Trial View text Trial 1 Toggle Message Event visibility o x Data Preferences 9 Untitled evs 41255ms Sms Sms 2m5 2ms Message 23719ms B Message 23836ms RT End Event Hidden Figure 5 7 Sample Temporal Graph View of Message Events Note that the default size of the message symbol in the temporal graph preference settings has been changed 5 5 1 Import Message List Experiments sh
90. e not appropriate she he can remove them by clicking on the Delete button on the Reaction Time Definition Manager dialog box a Reaction Time Definition Manager x Delete Selected RT Definition EyeLink Data Viewer 2002 2008 SR Research Ltd 49 Figure 6 8 Deleting Reaction Time Definitions 6 3 2 Viewing Reaction Time Information If the reaction time events are initialized such information is available for viewing in trial view window see Figure 6 9 In the spatial overlay view a red RT symbol is displayed near the end event In the temporal graph view a green line is drawn at the time when the start time message is presented and a red line is drawn at the time when the end event occurs to see these graphics make sure that the Display RT Graphics field in the General Trial View Preferences is checked see section 9 5 In the event list of the Inspector window select the end event that meets the reaction time definition for the selected trial The RT End Event field of that event is automatically checked This field will be unchecked and reaction time calculation will be updated if the user decides to choose another event as the RT end event by checking the same field of the newly selected event e EyeLink Data Yiewer i 15 x File Edit Analysis Window Help O 7 Moo Slel se BS tra fo Inspector PS Trial iew text Trial 1 E E f x Data w Preferences ajal text
91. eLink Data Viewer 2002 2008 SR Research Ltd 59 Trial time when the current fixation ends on the other eye in a binocular recording CURRENT FIX INTEREST Interest area in which the current fixation falls AREAS CURRENT FIX INTEREST_ARE Total amount of fixation dwell time in msec on A DWELL TIME the interest area to which the current fixation belongs A FIX COUNT which the current fixation belongs A GROUP current fixation is assigned AREA INDEX fixation falls A LABEL fixation is assigned CURRENT FIX INTEREST ARE The ordinal sequence of the current run of A RUN ID fixation s made towards the current interest area If the current interest area does not have a previous run of fixation s on it this variable will have a value of 1 CURRENT FIX INTEREST ARE Horizontal offset of the current fixation relative to A X OFFSET the center of the interest area If the fixation falls into multiple interest areas returns the offset value relative to the first relevant interest area only Returns a missing value for freehand interest areas Vertical offset of the current fixation relative to the A Y OFFSET center of the interest area CURRENT FIX IS RT END Whether the current fixation is the end event of RT definition CURRENT FIX LABEL Label of the current fixation CURRENT FIX MSG COUNT Number of visible messages associated with the current fixation event This number will not exceed the Maximum Message Vari
92. eas are deleted from the trial After loading the Interest Area Set for the trial is set to Custom Ag Auto Segment Image to Interest Areas Creates interest areas automatically for the trial bitmap a Save the Interest Area Set File Saves the trials interest area set to a file Display Image in Full If enabled overlay is not scaled to size of Trial Viewer Window and is instead set to actual size One pixel of overlay corresponds to one pixel of trial display Fi Change the Overlay Image Select the image to use as the background of the overlay Any existing background graphics are deleted Save Trial View as Image Creates an image of the spatial overlay view EyeLink Data Viewer 2002 2008 SR Research Ltd 16 Changes from the previous versions Note that when the background image for a trial is manually changed with the Change the Overlay Image button please also check for the Fit Overlay Image Change to Display setting in the Data Views gt Overlay preference If that setting is true the image is scaled to fit the display dimensions for the trial If false the image size is not altered and the image is centered on the trial overlay view 4 4 Temporal Graph Trial View The Temporal Graph View see Figure 4 5 allows the user to view trial data as a trace plot where the X axis represents time and the Y axis represents the X Y gaze location pupil size dived by a factor of 10 acceleration and velocity d
93. ed by SR Research is required to run this application and must remain connected to the PC while the application is running If a USB Dongle is not detected by the program the application will run in a DEMO mode supporting limited data loading EyeLink Data Viewer 2002 2008 SR Research Ltd 5 3 Working with Files The EyeLink Data Viewer can import EyeLink EDF files The viewer loads each data file into a Data Viewing Session DVS A DVS can consist of many EyeLink data files Only one DVS can be open within the Data Viewer at a time Once a DVS has been created and EyeLink data files have been imported into it the DVS file can be saved and then reloaded at a later date for future analysis It 1s much quicker to load a DVS than to load the original EDF files of which the DVS consists All changes made during an viewing session only affect the DVS data the original EDF files are never altered 3 1 Creating a Data Viewing Session DVS From the menu choose File gt New Tip A new viewing session can also be created by clicking the Create New Viewing Session tool 4 on the standard toolbar or press Ctrl N Tip To find out the meaning of a tool on the standard toolbar simply place the mouse over the tool 3 2 Opening an Existing Viewing Session To open an existing viewing session 1 From the menus choose File Open 2 In the Open dialog box browse to the location of the file and select it 3 Click Open Tip
94. efinitions the user may also selectively view and perform analysis on data within a specific period of time within a trial Interest Period For example the user may want to examine the eye data between two important markup messages for a trial with multi page manipulation analysis may be performed separately for the period of each page presentation The EyeLink Data viewer allows the user to create interest periods based on messages button events or duration To do that when programming an experiment the user should mark up possible interest periods with messages or other important events such as button presses If different images were shown within different interest period the user should also make sure that messages used to load images text or draw simple graphics be recorded with the scope of the intended interest period 6 4 1 Creating Interest Periods To create an interest period 1 Click the Interest Period List combo box at the far right hand of the application menu bar and select the Edit 2 Similar to the reaction time manager dialog see Figure 6 10 the user can create a new interest period by clicking the new button on the left edit an existing interest period by clicking on the button and remove an interest period by clicking on the button Click on the new 4 button In the Interest Period Editor dialog General Tab see Figure 6 10 enter a label for the current interest period in the la
95. eleration Trace Color and Pupil Sample Trace Color Set the colors to be used to show the horizontal and vertical position velocity and acceleration traces of the targets The default settings can be changed by clicking the corresponding cell and choosing a color from the palette or entering the value in RGB or HSB scales 2002 2008 SR Research Ltd 140 Acceleration Trace Scaling Factor and Velocity Trace Scaling Factor Set the scaling factor for the acceleration and velocity data so that these two traces can be displayed appropriately in this view Message Triangle Width Message Triangle Height Button Triangle Width and Button Triangle Height Set the width and height of the symbols for message and button events Background Color and Ruler color Set the colors for background and ruler of the temporal graph view Split Y axis If true 0 appear in the middle of the screen positive values on the top and negative values at the bottom otherwise a descending scale is used with large values on the Y axis appearing at the bottom of the screen Note this setting will only be effective when the data are loaded in a new viewing session X Trace Highlighted Y Trace Highlighted and Pupil Trace Highlighted Whether or not by default the X trace y trace and pupil trace are highlighted Initial Visible Sample Count Total number of initially visible samples in the temporal graph view window the default is 5000 Use X Positio
96. emsg printf TRIAL VAR LABELS PAGE Trial Variable Values eyemsg printf V TRIAL VAR DATA d num Images eyemsg_printf V IMGLOAD FILL Images s image fn eyemsg printf V AREA FILE Segments s seg_ fn 7 5 3 Picture Template One new feature of the Picture template is the demonstration of another approach to load images and to specify interest areas for the trial The third trial of the template loads individual images IMGLOAD TOP LEFT to create a composite image in the Viewer and reads individual rectangular interest areas directly LIAREA RECTANGLE All these changes listed in the following table were made in the w32_picture_trials c file of the template Data Viewer Functionality Message Commands Trial Variable Labels eyemsg printf TRIAL VAR LABELS TYPE Trial Variable Values eyemsg printf V TRIAL VAR DATA s imgname num Normal image eyemsg printf V IMGLOAD FILL images sacrmeto jpg eyemsg_printf V IMGLOAD FILL images sac_blur jpg Composite image eyemsg printf V IMGLOAD TOP LEFT s d od d Yd small images i points i x points 1 y SCRWIDTH 2 SCRHEIGHT 2 Composite image eyemsg printf V IAREA RECTANGLE d od od od d s i 1 points i x points i y points i x SCRWIDTH 2 points i y SCRHEIGHT 2 small images 1 7 5 4 EyeData Template The following table lists all of the changes made to the w32
97. enter 1s specified by lt erase red gt lt erase green gt lt erase blue gt The lt outer diameter gt and lt inner_diameter gt specified the diameters of the drawing circles Example MSG 9441901 V FIXPOINT 0 0 0 255 255 255 511 383 18 4 This draws a fixation point at 511 383 with a diameter of 18 pixels for the outer ring and 4 pixels for the inner ring The fixation point is drawn in black and its center 1s erased with white 7 3 4 6 Draw List File Identifier DRAW LIST Description When a large number of simple drawings have to be made it is easier to first record all of the simple drawings in a draw list file During the viewing session the viewer reads in the drawing commands from the pre recorded file and re creates the display drawing In a draw list file dlf each line represents one simple drawing or an image loading command written in the same format as mentioned above except that V directive is not necessary Format IV DRAW LIST lt relative path gt Example Example MSG 262495 V DRAW LIST BER s1106 dl1f The content of the file being CLEAR 255 255 255 TMGLOAD TOP BEET BER COlor bmp 772 G44 33 33 IMGLOAD TOP LEFT BER shape bmp 772 314 33 33 IMGLOAD TOP LEFT BER orient bmp 222 424 33 33 IMGLOAD TOP LEFT BER color bmp 552 94 33 33 This first clears the display and then loads four small bitmap images EyeLink Data Viewer 2002 2008 SR Research Ltd 92 7 3 5 Interest Area Commands The viewe
98. es will have a missing value if both eye samples are not available if pupils are missing or recording 1s done with left eye or right eye only In addition other user defined trial variable labels will also be listed Please note that the data output in the sample report depends on the setting of the interest period filter see section 6 4 2 or Figure 6 13 only those fixation and saccade events falling within the active interest period will be reported Ifa valid reaction time definition is found in a trial the TRIAL START TIME will be set as the start as the reaction time definition otherwise this will be set as the start of trial recording see section 6 5 3 on discussion of three time periods used in Data Viewer 6 10 Message Output Report Message output report provides a columnar output of messages written in each trial as well as the eye movement events to which the message is associated As with the other reports message report only outputs messages that fall within the active interest period for the trial 6 10 1 Obtaining a Message Output Report To obtain an output report for messages from the application menus choose Analysis Report gt Message Report 6 10 2 Variables in the Message Output Report Currently the following variables are included in the message output report RECORDING SESSION LABEL Label of the data file CURRENT MSG BLINK DURATI Duration of the blink to which the message is associated CURRENT
99. esearch Ltd 45 6 2 Fixation Map The EyeLink Data Viewer also allows the user to create a landscape view for a trial or for a group of trials with the same background image to visually identify the informative parts of the display To create a Fixation map for a single trial select the trial node in the top panel of the inspector window click the right mouse button and select Create Fixation Map option To create a Fixation map for a group of trials select the group node 8 Click the right mouse button and select Create Fixation Map option if no common image has been applied to the trials yet select Select Trial Background Image option before creating a Fixation map Section 9 3 lists all of the preference settings related to creating Fixation map Figure 6 4 Sample Fixation Map 6 3 Managing Reaction Time Definitions Another important application of the trial condition variables is for managing reaction time definitions for all the trials in the same experimental condition A typical trial recording could be ended in several ways such as a button response a saccade event a fixation event or a special message To obtain an accurate reaction time RT measure the EyeLink Data Viewer relies on a set of reaction time definitions to parse the start and EyeLink Data Viewer 2002 2008 SR Research Ltd 46 end events for RT calculation The reaction time manager allows the user to configure the way i
100. esents the location of the samples or events being plotted This view is suitable for a wide range of experimental paradigms including those using dynamic trial displays The scale of the graph can be changed via zoom in and zoom out operations This view supports binocular display of sample position and pupil size traces The color of individual events as well as the global color of a given event type or sample trace can be changed as desired There is a vast number of preferences that can be configured by the user saved and then applied to future loaded data The Animation View plays back the subject s gaze data in a trial with a concurrent time code displaying the time from the start of trial recording If the image that was shown during the trial recording is available it can be loaded as the background for the playback view A trackbar control displays the progress of the playback and lets the user select a specific position to start playback The speed of playback can also be adjusted Multiple viewing windows can be opened at one time displaying data from different trials or displaying data of one single trial in the Spatial Overlay View Temporal Graph View and Animation View concurrently EyeLink Data Viewer 2002 2008 SR Research Ltd l 1 2 Event Selection EyeLink events can be selected for either of the data views temporal graph view or spatial overlay view Detailed properties of the selected event can be examined wit
101. est area is selected whether or not to select fixations inside the IA as well Initial Data View 1 TP 2 OL 3 AV Selects the mode 1 temporal graph mode 2 spatial overlay mode 3 animation playback mode of the trial view window when the data is first loaded Display RT Graphics If reaction time definitions are initialized whether or not to show the RT symbol in the spatial overlay view and to draw the Reaction Time Start End lines in the temporal graph view of the trial data Include Graphics Commands Sent Prior to IP If no graphics commands are found within the current interest period uses those sent prior to the current interest period EyeLink Data Viewer 2002 2008 SR Research Ltd 136 9 6 Spatial Overlay View Preferences The spatial overlay view preference settings cover the following parameters Sample Trace Color Sets the color to be T Data ff Preferences used to show the sample trace Preferences General Display Fixation Index Display Fixation Data Loading Duration and Display Saccade Opu anana Index Whether or not to show the z ae ded fixation index fixation os eer duration saccade index in the spatial Time Plot overlay view Animation Field Value Display Fixations as Scan Path If checked two temporally contiguous LSS ees fixations are connected by an arrow pointing towards the more recent AERD oin Concurrent Selecte Joint Concurrent Selected Fixations F
102. ether the current saccade 1s the reaction time end event see section 6 3 1 for reaction time definition Whether the current saccade is hidden from viewing and EyeLink Data Viewer 2002 2008 SR Research Ltd 28 pf outputamalysis o Manually Adjusted Whether the saccade has been adjusted manually Color To achieve better visibility the color of the currently selected saccade can be changed by clicking on the color toolbox 5 3 1 Merging Saccades Sometimes a large saccade is followed by a small corrective saccade or vice versa Thus two or more temporally contiguous saccades could be merged This can be done by selecting the saccades and clicking the Merge Selected Items button LS on the toolbar or clicking the right mouse button and selecting merge Once the saccades are merged information on the ordinal sequence for the current and subsequent saccades is updated and the fixation between the two merged saccades 1s deleted Note Only two or more temporally contiguous saccades can be merged If saccades are selected that are not temporally contiguous only the neighboring saccades will be merged 5 4 Blink Events Blink events see Figure 5 5 can be toggled on off by clicking the Toggle Blink Event Visibility button Blink is represented as a colored solid line in both the spatial overlay view and the temporal graph view Each field of the blink event properties is listed in the following table Those fields that
103. ewer are marked with an asterisk e EyeLink Data iewer i x bieles Moloy lelelele o BE Fumar KEEN 18670 19104 19538 19973 20407 2084 21275 21709 22144 22578 23012 23446 l l l l l 0 px a olelo ela xlele a a is P Trial Yiew text Trial 1 amp Data w Preferences 9 Untitled evs E p text 3 9 CI Trial 2 CI Trial 3 a O Trial 4 Interest Grea Templates 33 66 Button 31ms 99 132 165 198 utton 23719ms Time 3584 ms 232 State ressed 265 53 1 Figure 5 8 Sample Temporal Graph View Showing the Button Events Note that the default size of the button symbol in the temporal graph preference settings has been changed Label of the button event Time Trial time when the button was pressed released Note that if the button event occurs before the trial starts a negative time value will be displayed Button ID Button pressed or released X Y Concurrent gaze coordinates when the button is pressed released 100 if no gaze information was available for the time of the button event event see reaction time definitions output report EyeLink Data Viewer 2002 2008 SR Research Ltd 33 Color To achieve better visibility the color of the currently selected button event can be changed by clicking on the color toolbox
104. f a freehand interest area by pressing the ESC key 6 Enter the name of the Interest Area and press Enter 7 Repeat steps 2 6 to create more interest areas of the same type Press the Selection mode icon A from the Application Desktop toolbar to end creating interest areas a Trial Yiew picture Trial 1 _ O x fled Area of Interest Name FreeHand caren Figure 5 11 Creating a Freehand Interest Area Several Interest Areas of the same type can be created in a sequence by following the above steps 5 8 2 Creating Interest Area Image Segmentation If a trial bitmap has already been loaded the Data Viewer can create interest areas for the trial by auto segmentation This is done by clicking the Auto Segment Image to Interest Area button AS in the toolbar of the spatial overlay view window Note Using the auto segmentation feature will remove all of the pre existing interest areas for the trial Auto segmentation is more feasible for those displays in which the EyeLink Data Viewer 2002 2008 SR Research Ltd 37 individual items can be easily isolated such as in reading and visual search studies where a background of a single color is present but not good for some visual scenes in which the boundaries between individual elements are not clearly defined see Section 9 7 on preference settings for image segmentation 5 8 3 Saving Interest Areas To save interest areas of a trial to be used
105. ferent interest periods by selecting the desired interest period from the list For each interest period only those events falling within that period are shown in the spatial overlay temporal graph views and in the event list of the inspector window In addition only those events and data within the selected interest period custom defined interest period or the default Full Trial Period are exported to the output file One important variant of the interest period is the reaction time period Reaction Time Definitions RTD can be created and applied to all trials loaded into an EyeLink Data Viewer session Each RTD can have a set of trial condition variables that must be matched for the RTD to be applied to a given trial The message event to use as the start time for the reaction time can be defined Each RTD can have a fixation saccade button or message event as the ending event for the reaction time calculation Depending on the event type selected for the reaction time end event a set of event properties can be specified to determine which event should be used within each trial A number of RTDs can be created for a given Data Viewer session allowing multiple reaction time conditions to be specified Each trial will only be matched to at most one RTD 1 6 Data Output and Analysis Both Spatial Overlay and Temporal Graph trial views can be saved as JPEG images for illustrative purposes A series of output reports can be run fo
106. ffect the user has to reload the data file again EyeLink Data Viewer 2002 2008 SR Research Ltd 114 Fl Jb Data a Preferences Preferences og General Save Properties as Defaults a Dat Restore Factory Defaults Data views loadFixatins WS Load Saccades e OOo Loads eooo Load Messages W LoadButtons OM Fully Load Trials into E Trial Load Start Messa TRIALID Trial Load End Message TRIGL RESULT Trial Variable Labels M TRIGL VOR LABELS Trial Variable Values M Exclude Message String ae Figure 8 7 Modifying and Saving the Preference Setting of Data Loading Once the above changes have been applied and the data is reloaded into the viewing session the user will notice that in the Trial Variable Value Editor dialog each column lists the values extract from the data file for a trial condition variable whereas the first row of the dialog box reads as File Trial Variable 0 Variable 1 To assign more meaningful labels for the trial variables start the Trial Variable Manager dialog select the variables and edit their labels while keeping the default values unchanged see Figure 8 8 EyeLink Data Viewer 2002 2008 SR Research Ltd 115 Trial ariable Manager X Analysis Variables Trial_ FileName Unknown Practice Unknown Discriminability Unknown Variable 3 Unknown _i ae Selected Variable Label IF eature s Default value Ju nknown Close
107. g for the next interest area to use in the fixation sequence analysis variables of the Interest Area report Default is 1 Can not be less than 1 EyeLink Data Viewer 2002 2008 SR Research Ltd 132 9 4 Data Filter Preferences The data filter preference settings consist of the following elements a Inspector Memory L sal a Data if Preferences Preferences General l_ Data Loading Be Output f Analysis ie Data Filters HA Data Wiews Field Value Merge Nearby Fixati 7 Fixation Merging A Fixation Duration Th Se x Display Blink Sacca Hide Fixations Beyo Show Interest Area Show Interest Area a 4 Hide Eye Events On Hide spanned Even Tritn panned Fixati Include Display Com Include Audio Cor qa aaa Merge Nearby Fixations If checked merge the neighboring brief fixations A fixation to be merged must have a duration of less than that specified by Fixation Duration Threshold and be within 1 of the target fixation These default thresholds are set in the Amplitude Threshold and Fixation Duration Threshold fields Fixation Merging Amplitude Threshold Sets the amplitude threshold for fixation merging The default value is 1 0 Fixation Duration Threshold Sets the fixation duration threshold for fixation merging A fixation will be merged if Merge Nearby Fixations
108. ge Name Mapping If the Auto Select IAS for Trial property in the Output Analysis preference settings is true the value in this field will be used to associate the IAS to trials automatically see section 5 8 8 Automatic Trial Image Interest Area Set Association for details 4 1 1 5 Custom Interest Area Set Empty Interest Area Set For each trial the tree view also shows whether or not a custom interest area set has been defined for the trial If there is no interest area set the node L amp will be Empty Interest Area Set The property panel lists the same elements as the interest area templates except that the IsCustom field is true for the custom interest area set 4 1 2 Preferences Tab The preferences tab Figure 4 2 right panel provides access to all the elements of the data viewer that can be configured by the user These include everything from the default colors used for displaying events to the elements of an EDF file to load These elements are broken down into the following five categories General Preferences Data Loading Preferences Output Analysis Preferences Data Filters Preferences General Trial View Preferences Spatial Overlay View Settings Temporal Graph View Settings and Animation Playback Settings 4 2 Trial View Window The Trial View window displays the data of a selected trial in a Spatial Overlay Mode a Temporal Graph Mode or an Animation Playback Mode Selecting a trial in the
109. he EyeLink Data Viewer 1s a tool that allows the display filtering and report output of EyeLink I and EyeLink II EDF data files The Data Viewer includes the following areas of functionality 1 1 Data Visualization The EyeLink Data Viewer supports three trial based viewing modes the Spatial Overlay View the Temporal Graph View and the Animation View In the first two viewing modes the user can specify which event types to display including fixations saccades blinks messages and buttons Sample traces can also be displayed The animation viewing mode plays back the gaze data of a selected trial The Spatial Overlay View allows a trial to be viewed superimposed on the background image that the participant was looking at while the data was being recorded This view is ideal for relatively static trial presentations like reading or visual search paradigms Fixations can be displayed as either circles or as a scan path Saccades can be displayed as lines with an arrow specifying the saccade direction Blinks can be displayed as a line joining the last valid sample position prior to the blink and the first valid sample following the blink Message and button events can be displayed as a small rectangle where the position of the event is determined by the position of the nearest sample recorded at the message or button time The Temporal Graph View provides a two dimensional plot of trial data The X axis represents time while the Y axis repr
110. he sentence prior to leaving that interest area in a forward direction 1 if a saccade exits the current interest area to a lower A_ID to the left in English before a later interest area was fixated 0 if not IA REGRESSION OUT FULL Whether regression s was made from the current interest area to earlier interest areas e g previous parts of the sentence 1 if a saccade exits the current interest area to a lower IA_ID to the left in English 0 if not Note that IA REGRESSION OUT only considers first pass regressions whereas IA REGRESSION OUT FULL considers all regressions regardless whether later interest areas have been visited or not IA REGRESSION OUT FULL C Number of times interest area was exited to a OUNT lower IA_ID to the left in English IA REGRESSION OUT COUNT Number of times interest area was exited to a lower IA_ID to the left in English before a higher IA ID was fixated in the trial IA REGRESSION PATH DURA The summed fixation duration from when the current interest area 1s first fixated until the eyes enter an interest area with a higher IA ID IA RIGHT Right side pixel position of non freehand IA IA REGRESSION PATH DURA The summed fixation duration from when the current interest area 1s first fixated until the eyes enter an interest area with a higher IA ID IA RUN COUNT Number of times the Interest Area was entered and left runs IA SECOND FIXATION DURA Duration of the second fix
111. hich a moving resource is used the user may need to keep track of the position of the resource The Data Viewer allows the user to calculate the position velocity and acceleration data for each individual samples in the sample output report With such messages position velocity and acceleration traces can be displayed in the time plot view Identifier Default TARGET Pos Description This message specifies the position and visibility of the targets at the specific message time The command identifier can be changed in the data loading preference settings Format iy TARGET POS largel Reyr lt target Xy Carget Vj stargeu d visibility gt lt target 1 step gt lt Target2 Key gt lt target2 x target2 y gt lt target 2 visibility gt lt target 2 step gt Where lt Targetl Key gt and lt Target2 Key gt the tokens to extract the position s Of targets lt targetl x targetl y gt and lt targetZ x tartget2 y gt the position s of the targets The coordinates must be enclosed in a pair of brackets lt target 1b Visibility gt and lt target A VvVisibiility gt at dy the targets are visible if 0 the targets are hidden lt target 1 step gt and lt target 2 step gt if 1 the position of the target will be in steps if O the position of the target is interpolated across samples Example EyeLink Data Viewer 2002 2008 SR Research Ltd 95 MSG IO FTOOO i 5 IN TARGET POS TARG 301 27 6 07 TARG
112. hin a Inspector Window that also provides a list view of all visible events in the selected trial Properties of a selected event that are editable by the user like the events color can be modified directly within the inspector window 1 3 Interest Area Definition The Spatial Overlay View allows creation of any number of interest areas for the trial Rectangular elliptic and freehand interest area shapes can be created The position and shape of the Interest Area can be modified after Interest Area creation Users can view fixation based statistics for a selected interest area including the fixation count and total dwell time for the interest area as well as the proportion of fixations and dwell time relative to the trial totals Interest area templates can be created which can then be applied to multiple trials speeding the process of defining interest areas for multiple trials 1 4 Event Filtering The EyeLink Data Viewer supports data filtering including deleting merging and drift correcting event types Not all filtering functions are available to all event types The original EyeLink EDF file is never modified by the Data Viewer so the originally recorded data is always available Any event can be hidden within the Data Viewer either manually or through the definition of some spatial or temporal filtering preferences Hiding events allows the user to focus on a subset of a trial s data Hidden events can be made visible again
113. iable and type in the default value in the Default Value edit box Be sure to press Enter to register the change you made To create a new variable click the button on the left A new variable label EyeLink Data Viewer 2002 2008 SR Research Ltd 43 with a default value default value will appear Select the variable and change its label and default value in the two edit boxes DO NOT include quotes for text strings To remove one variable select it in the list and click the delete button Sometimes the order in which the variables are listed is important This is especially true when you want to match the variables created with the Trial Variable Manager and the values read from the command messages in EDF file e g TRIAL VAR DATA TRIALID see the preference settings on data loading To do that simply select the variable and use the or button to move it to the desired position 6 1 2 Trial Variable Value Editor The variables and their values can be viewed and edited in the Trial Variable Value Editor dialog box e Trial Yariable Yalue Editor PAGE CONDITION i 1 undfined SY eFault value Ts Treks ea vat Figure 6 2 Trial Variable Value Editor Dialog default value To activate the dialog box from the menus choose Analysis Trial Variable Value Editor The top row of the dialog box lists the filename variables imported from the EDF file as well as variables created by the Trial Va
114. idual items can be easily isolated such as in reading and visual search studies but probably not good for some visual scenes in which the boundaries between individual elements are not easily defined A third approach 1s to create interest areas manually by following the procedure outlined in section 5 8 1 Creating Interest Areas The created interested areas by auto segmentation or manually can be saved by clicking the Save the Interest Area Set File We button from the menu bar of the trial spatial overlay view window 8 3 2 3 Manipulating Trial Condition Variables The EyeLink Data Viewer allows the user to manage a list of trial condition variables and assign values for these variables in a given trial see section 6 1 In the current example the TRIAL VAR LABEL command imports a list of trial condition variables and the TRIAL VAR DATA command extracts the values for these variables these two default messages can be changed in the data loading preference settings see section 9 2 To review and manage the list of variables and assign default values for these variables click Analysis Trial Variable Manager from the application menu bar To examine or change the values of the variables for a given trial click Analysis gt Trial Variable Value Editor Trial Yariable Manager x Analysis Variables TRIAL_FILENAME DISCRIMIMABILITY i Selected Variable Label Pra etice Trial Default Value Test Close
115. ile name with an appropriate extension the common file extensions that the Viewer supports are txt or xls EyeLink Data Viewer 2002 2008 SR Research Ltd 120 a Gutput Report X Available Output Variables Selected Output Variables BLINK_COUNT BUTTON_FRES5_COUMNT DURATION END _TIME INTEREST ARES SET MESSAGE _ COUNT SAMPLE COUNT START_TIME RECORDING SESSION _LABEL DISCRIMINABILITY FEATURES a PRESENCE SETSIZE y AVERAGE FIXATION DURATION AVERAGE SACCADE AMPLITUDE FIMATION COUNT SACCADE COUNT REACTION TIME xl Exclude Trial String ai Figure 8 12 Obtaining a Trial Output Report Once a trial output file is obtained the data can be imported into a statistical package and analyses can be performed on the variables in question RT and number of fixations in the current example Note that for some statistical software the user may have to modify the default variable labels so that the data can be successfully loaded Also note that Tab is the delimiter used by the Viewer to separate neighboring variables For some statistical packages it may be desirable to check Use Quotes around String Text Variables to make sure that any space within a string will not be treated as a delimiter The following graphs show the results for reaction time and the number of fixations per trial in each search condition following the removal of practice trials and those trials with no matching reaction time definit
116. indtasanseSetes 88 7 3 4 SMP TOT a WAIN Oia Raceline e tele E alates 89 Pomel Clear Overlay VIEW oceana en wescssei asin E E E A 89 TOA ECAN i a teeth stan ois dnieo wan aadene ete aeteap eit ecas ieee 90 TIA WDrawitioa Rectan le e335 T eect 90 Toes Drawing a Filled RECN Cc sokes css cadannkiecnicueniin eae ANE e 9 Toe Diawne aT Kinon POM pris es ayeeetadin cede es N 9 Tne Os Draw Let TG aaah a a nats auel a cacneti ntl lit Goel A 92 EyeLink Data Viewer 2002 2008 SR Research Ltd 1v 7 3 5 Interest Area Command c ccccccccccecceccececceccecccecescesceceecescesescescceacs 93 Poco Rectangular reS CAC T eeir A N A 93 Taa BiipieiIntere stAT deoioinen a T TO 93 Lox Freehand INEC TAT ani a iene elect ec cesosmrdeidastecvly ened 94 Poe mter ATI Sel a a T sateen a 94 7 3 6 Target Poston COMmNaNdS ueser nna AT TA 95 T4 Reaction Time Demmi ONS erreren ie a EE EE 96 7 4 1 IBUTON EE VCI ar a E ee ad O O 96 7 4 2 PIXON EVED esre i E E E T AE EEN 97 7 4 3 R216 672 16 oo E VONS ate ee nn Pe ene 98 7 4 4 Message EVENTS ensien a O 99 7 4 5 Reaction Time Definition Set ccccccccccccccccceceeeeesaaeeseeeeeeeeeeeeeeeees 99 7 5 Changes Ia the Sample EXPerimeniS assire n E a 100 7 5 1 Spie Template ra a T E A ee 100 Loe iia lt ale B 91 0 Fe eS ae le 100 T5 PICUULe Templie eroaa a a a A ET 101 7 5 4 Bye Data Tempi eee ne eee E N 101 1 GC WInGOW Template tiarna 102 7 5 6 CONTO EMM LATS erea caer lat nits lead
117. ing hiding and deleting operations are common to all event types fixations saccades buttons blink events and messages whereas merging and drift correction 1s available to fixation and saccade events only The common operations are discussed in this section whereas the unique operations pertaining to certain types of events are documented in the relevant event section 5 1 1 Selecting Events To select an event fixation saccade blink button or message place the mouse cursor over the event either in the spatial overlay temporal graph view or in the event list of the inspector window and click the left mouse button To select more than one event hold the CTRL key down and select the target event until all desired events are selected If all events in a trial are to be selected simply click the Select All Visible Item button on the toolbar or click the right mouse button and select Select All To select a group of events within a square region place the mouse cursor at the top left corner of the region Click and hold down the left mouse button drag the mouse cursor to the bottom right corner of the square region and then release the left mouse button Tip Holding the CTRL key while selecting an event leaves previously selected events selected If the CTRL key is not pressed previously selected events are unselected 5 1 2 Deleting Events Select the events and click the Delete Selected Items button on the toolba
118. iod Editor General Tab 00 s0sssesseeeeeeeseesecccccnenacceeesenss 52 Figure 6 11 Interest Period Editor Details Tab 0 0 0 eccccccececeeeeeeeeeeeeeeeeeeeeeeeeeeeees 52 Figure 6 12 Selecting Output Variables in a Trial Report ccccccceeeeeeeeeeeeeeeeeees 55 Figure 6 13 Using Interest Period for Event Filtering ce ececccccceeeeeeeeeeeeeeeeeeeeees 58 Figure 6 14 Progress Dialog Box Displayed when Creating the Interest Area Report 71 Figure 8 1 The first Viewer Screen after Loading HD RCN EDF file 000 111 Figure 8 2 Saving a Viewer Viewing Session sssss00eeesessssssssssssssseettrrereeresssssss 111 Figure 8 3 Opening a Saved Viewer Viewing session ccccccccccceeeeeeeeeeeeseeeeeseeeees 111 Figure 8 4 Creating a Screen Capture of the Spatial Overlay View or the Temporal GPE Vie WO a TAa eee E E T E EE 112 Figure 8 5 Using the Trial Variable Manager Creating a New Variable 113 Figure 8 6 Using the Trial Variable Value Editor Modifying a Default Value 114 Figure 8 7 Modifying and Saving the Preference Setting of Data Loading 115 Figure 8 8 Using the Trial Variable Manager Changing Variable Labels 116 Figure 8 9 Creating Editing Reaction Time Definition General Tab ee 117 Figure 8 10 Creating Editing Reaction Time Definition Reaction Time Tab 118 Pioure o201 Moromo Pix ations iernare a a E
119. ion Output Report To obtain a fixation output report select Analysis Report Fixation Report from the application menu Select all of the desired variables and enter them to the list of selected output variables see Figure 8 14 Click the Next button and in the Filename edit box enter the desired file name with an appropriate extension xls or txt The following Figure 8 15 Tables 1 and 2 present the analysis output for the distribution of fixations as a function of distractor type EyeLink Data Viewer 2002 2008 SR Research Ltd 123 90 90 Low Discriminability High Discriminability 80 N O O O Fixations Fixations 1 2 2 3 3 4 4 5 5 6 gt 6 1 2 2 3 3 4 4 5 5 6 gt 6 Saccade Size Saccade Size Color Shape Orientation 90 Low Discriminability m High Discriminability d m Hh 90 80 O N O O O Ql O ea iN O Fixations Fixations 30 30 40 kyr A 10 0 0 1 2 23 34 45 56 gt 6 1 2 23 34 45 56 gt 6 Saccade Size Saccade Size in degrees Color Shape Color Orientation Shape Orientation Figure 8 15 Average proportion of fixations assigned to distractors sharing target color shape orientation in the single feature search task top panels and to distractors sharing target color shape color orientation or shape orientation in the two feature search task bottom panels as a function of saccade amplitude N
120. ions EyeLink Data Viewer 2002 2008 SR Research Ltd 121 3500 3500 Low Discriminability High Discriminability 3000 3000 2 2500 g 2500 i 2000 2000 aD e9 u u Cc Cc Q O 2 1500 2 1500 ad ad 1000 OQO OQO O 500 500 Display Size Display Size 12 Low Discriminability High Discriminability Number of Fixations Number of Fixations 6 12 24 Display Size Display Size SF Absent A TF Absent amp SF Present amp z TF Present Figure 8 13 Response Time in msec and Number of Fixations per Trial as a function target presence and display size in both the single feature SF and two feature TF search tasks in the high discriminability N 8 and the low discriminability conditions N 8 8 3 5 2 Fixation output report Similarly a fixation output report can be obtained The fixation output report generates one row for each visible fixation within the Viewer including several variables EyeLink Data Viewer 2002 2008 SR Research Ltd 122 describing the current fixation as well as a set of relative variables describing the previous and next fixations and saccades see section 6 6 2 for a complete list of variables in the fixation report For the current example since we are interested in whether the distribution of fixations differed across different types of display items we need to select variables such as fixation index the closest interest a
121. is Mol Bele e2 p elR Farar 7 a Inspector n ESR Trial 1 oO x Data Preferences H HORCH a g ED Trial 2 DD Trial 3 a Trial 4 H Trial 5 ED Trial 6 ED Trial 7 EI Trial 8 TP Fixation 8ms lt gt Fixation 316ms TP Fixation 464ms TP Fixation 956ms lt gt Fixation 1156ms lt gt Fixation 1304ms lt gt Fixation 1532ms lt gt Fixation 1688ms lt gt Fixation 1848ms lt gt Fixation 1944ms lt gt Fixation 2180ms TP Fixation 2364ms lt gt Fixation 2540ms lt gt Fixation 3140ms daw f a Start EyeLink Data viewer 5 06 PM Figure 8 1 The first Viewer Screen after Loading HD _RCN EDF file EyeLink Data Viewer 2002 2008 SR Research Ltd 110 For the current tutorial load the HD RCN EDF file from the VisualSearch directory the search target for that subject was an upright red C The first screen following the data loading should look like the one below see Figure 8 2 At any time the viewing session can be saved by clicking File Save from the application menu bar or File Save As for a different viewing session name In the Save dialog box enter the desired viewing session name see Figure 8 3 x Look in VisualSearch E a ae segments aena search Save Files of type viewing Session Files Cancel Figure 8 2 Saving a Viewer Viewing session A saved
122. ixation 1848ms TP Fixation 1944ms lt gt Fixation 2180ms TP Fixation 2364ms lt gt Fixation 2540ms lt b gt Fixation 3140ms General Reaction Time Label RT_Absent Type Button Event x Trial Condition Qualifiers TRIAL_FILENAME PRACTICE Selected Value DISCRIMINABILITY FEATURES Trial Conditions D_RCN EDF ecording File 25051648 ms 25054982 ms aoa EyeLink Data Viewer tart Time nd Time start Figure 8 9 Creating Editing Reaction Time Definition General Tab 5 24 PM Click the Reaction Time Tab see Figure 8 10 Because the start event of reaction time calculation is the onset of the search display keep the start time message text as SYNCTIME From the button number combo box select button 3 this number depends on the actual button designated as the response button and set the button state as Pressed EyeLink Data Viewer 2002 2008 SR Research Ltd 117 a Reaction Time Definition Editor x Start Time Message Text fevn C TIME End Time Button Number 3 Released f Pressed Figure 8 10 Creating Editing Reaction Time Definition Reaction Time Tab Once this has been done close the Reaction Time Definition Editor dialog From the Reaction Time Definition Manager dialog repeat the process of RT definition for target present trials Label RT Present Type Button Event T
123. l Drift Correct Ctrl D Select All Ctrl A Fix Select Hidden q Trial Grouping Ctrl Avg x Position Avg Y Position 7 0 Figure 5 3 Drift Correcting Fixations on One Line of Text 5 2 3 2 Precise Drift Correction of a Single Fixation To carry out more precise drift correction of one fixation 1 Select the fixation to be drift corrected 2 In the property panel of the Inspector window select the entry for Avg X Position and type in the desired X position 3 Select the entry for Avg Y Position and enter the desired Y position EyeLink Data Viewer 2002 2008 SR Research Ltd 25 Note Drift correcting one fixation or a group of fixations changes the properties of some relevant events such as the start end point of a preceding or following saccade and its amplitude Tip Before moving the fixations it is desirable to turn off the interest area set by pressing Toggle Interest Area Visibility button in the application desktop toolbar Otherwise the interest area s within which the fixations appear will also be moved along 5 2 3 3 Cleaning Fixations For some studies researcher may want to clean up fixations based on certain rules Data Viewer provides two options for fixation cleaning 1 Fixation Filter preferences The user can filter out small fixations with Merge Nearby Fixations Fixation Merging Amplitude Threshold and Fixation Duration Threshold
124. l one Example MSG 329381 V RT BUTTON SYNCTIME 5 1 TYPE normal In this example the end event for RT calculation is pressing button 5 serves This RT definition is applicable to the condition in which the value of the variable TYPE is normal 7 4 2 Fixation Events Identifier FXATION Description This will end the trial by the appearance of a specific fixation The user can specify the parameters of the fixation end event the minimum fixation duration in milliseconds required the xy coordinates for the region center as well as the diameter of the fixation region Pre Trial Message Command Format VORI FIXATION xr Start msg lt Tixation duration gt lt x gt lt y gt lt diameter gt CONDITION LABEL 1 condition value 1 CONDITION LABEL 2 condition value 2 Trial specific Message Command Format EyeLink Data Viewer 2002 2008 SR Research Ltd 97 Iv ECR FIXATION bu start mog gt lt Erxation OuralLlons lt x my lt diameter gt Note If the location information of the target fixation 1s not important set the values of x y and diameter as 1 Condition labels and their values are not required for the trial specific message command and optional for the pre trial message command if not specified the RT definition is applied to all conditions Example MSG 329381 VRE FIXATION SYNCTIME 500 I 51 1 In this example the RT end event is the occurrence of the first fixation with a minimu
125. l start time Note The calculation of the angle between the previous next fixation and the current fixation is directional with the arrow pointing towards the previous next fixation see Figure 5 2 for an illustration of angle calculation EyeLink Data Viewer 2002 2008 SR Research Ltd 23 Previous text Fixation 10s lat g5 Current Fixation 40 Figure 5 2 Diagram for Angle Calculation Note The direction of the previous next fixation relative to the current fixation is determined as LEFT if the angle is greater than 135 or less than 135 UP if the angle is between 45 and 135 RIGHT if the angle is between 45 and 45 and DOWN if the angle is between 135 and 45 5 2 1 Selecting Fixations In addition to the common method of event selection by mouse fixations may also be selected by using the cursor keys up down left and right cursor keys To select a group of temporally contiguous fixations select the first fixation by mouse and press the up cursor key to select the next fixation until all target fixations are selected Use the down cursor key to unselect the recently selected fixations The left or right cursor key can be used to choose a group of fixations earlier or later in the temporal sequence 9 2 2 Merging Fixations In some cases two or more temporally contiguous fixations can be merged and represented as a larger fixation To merge fixations
126. lay view used only if the trial bitmap is not loaded Maximum Graphics Commands to Process Sets the maximum number of graphics commands to process in each trial This command is useful for those trials in which there are many viewer graphics commands while the user may just need to see a few of them If it is set to 1 the viewer will process all graphics commands For all other entries of integer numbers the viewer will process the number of graphics commands specified when creating background image for overlay view Fit Overlay Image Change to Display If True when the background image for a trial is manually changed the image is scaled to fit the display dimensions for the trial If false the image size is not altered and the image is centered on the trial overlay view EyeLink Data Viewer 2002 2008 SR Research Ltd 138 9 7 Image Segmentation Preferences The parameters related to the auto image segmentation preference settings are covered below Segmentation Spacing Threshold Number of E gt Data aA Preferences consecutive pixels below threshold before segment end is identified 3 Preferences di General Data Loading Left IA Buffer Size Right IA Buffer Size Top IA bai ee u Buffer Size Bottom IA Buffer Size Number PPa a rate of pixels added to the left top right and G E Overlay bottom of the interest area Note that the Top ge eae Segmentation IA Buffer Size Bottom IA Buffer Size fields coe
127. le will be used EyeLink Data Viewer 2002 2008 SR Research Ltd 47 2 Click on the 4 button In the Reaction Time Definition Editor dialog General Tab see Figure 6 6 a Enter a label for the current RT definition in the Label edit box b Select the type of RT end event from the Type combo box c Inthe Trial Condition Qualifiers group box select the trial condition variables and enter the intended values for the current RT definition DO NOT include quotes for text strings e Reaction Time Definition Editor x General Reaction Time Label new FT 01 Type Saccade Event Trial Condition Qualifiers Selected Value Trial Conditions Figure 6 6 Reaction Time Definition Editor General Tab 3 Select the Reaction Time tab see Figure 6 7 e Reaction Time Definition Editor x General Reaction Time Start Time Message Text SYN C TIME End Time Minumum Saccadic Amplitude s o Saccade End Point Center Jano 1 384 Region Diameter fso o Figure 6 7 Reaction Time Definition Editor Reaction Time Tab The layout of the Reaction Time tab depends on the type of end event you selected in the General tab One common feature though is the configuration of the start time message In the Start Time Message Text edit box type in the intended message string the default is SY NCTIME Button Event EyeLink Data Viewer 2002 2008 SR Research Ltd 48 This will treat a particular button pres
128. lets the user select a position to start playback View Trial Spatially with Image Overlay Select the spatial overlay mode an View Trial Data in 2D Temporal Graph Mode Select the temporal graph mode Te Playback Trial Starts playing back the trial data Stop Trial Playback Stops the playback and resets the time code and gaze Cursors Pause Trial Playback Pauses the playback EyeLink Data Viewer 2002 2008 SR Research Ltd 19 Forward Step Each click on this button advances the playback by one video frame Save Trial to Movie File Save the playback of the trial into a movie file on Trial View tent Trial 1 Sjorx a Fir speea fico s k E 00000000 ms Buck did not read the newspapers or he would have known that trouble was brewing not alone for himself but for every tide water dog strong of muscle and with warm long hair from Puget Sound to oan Diego Because men groping in the Arctic darkness had found a yellow metal and because steamship and transportation companies were booming the find thousands of men were rushing into the Northland These men wanted dogs and the dogs they wanted were heavy dogs with strong muscles by which to toil and furry coats to protect them from the frost Buck lived at a big house in the sun kissed Santa Clara Valley Judge Miller s place it was called It stood back from the road half hidden among the trees through which glimpses could be caught of the
129. lt and can be configured in the target position string of Data Loading preference settings followed by parameters of the individual targets The scale in which the vertical data is displayed can be changed by clicking the right mouse button when the mouse cursor is placed on the Y axis and choose one of the following options ascending large values on the Y axis appear on the top of the screen descending large values on the Y axis appear at the bottom of the screen or split 0 appear in the middle of the screen positive values on the top and negative values at the bottom The X Y and pupil traces can be highlighted Press the x key to highlight the X trace press the y key to highlight the Y trace and press the p key to highlight the Pupil trace If pressing one of these keys does not highlight the intended sample traces please make sure that the trial view window is currently in focus double clicking anywhere the sample traces are plotted to set the keyboard focus to the trial view window Various aspects of the time plot view can be configured in the preference settings Preferences gt Data Views gt Time Plot For example the user may change the colors of the sample traces the scaling factor for plotting the acceleration velocity and pupil size data total number of initially visible samples in the temporal graph view window etc EyeLink Data Viewer 2002 2008 SR Research Ltd 18 4 4 2 Zooming Operations
130. lude Trial String edit box the fixation report similarly the saccade report and the interest area report also allows the inclusion of hidden events in the relative event variables PREVIOUS and EyeLink Data Viewer 2002 2008 SR Research Ltd 64 NEXT This can be done by clicking the Include Hidden Events in Relative Variables check box If the hidden events are included in the analysis the user can further decide whether or not to treat these events as missing data 6 7 Saccade Report Saccade report creates a columnar output of saccade events in the data file Each row of the report represents a saccade event Depending on the variables selected for output each row can contain information on the previous fixation and or saccade as well as the next fixation and or saccade 6 7 1 Obtaining a Saccade Report To obtain a saccade report adopt the same procedure as in obtaining the trial report except from the menus choose Analysis Report Saccade Report 6 7 2 Variables in the Saccade Report Currently the saccade report includes the following saccade related information index start time end time start xy coordinates end xy coordinates duration amplitude angle direction average velocity peak velocity interest areas of the current previous and next saccades and whether these saccades have been selected for analysis It also contains the following information on the previous fixation and the next fixation
131. m duration of 500 milliseconds whereas the location information of the fixation is not important 7 4 3 Saccade Events Identifier SACCADE Description This will end the trial by the appearance of a specific saccade The user can specify the parameters of the saccade end event the minimum saccadic amplitude in degrees of visual angle required the xy coordinates for the region center as well as the diameter of the fixation region Pre Trial Message Command Format V RINVSACCADE lt rt start msq gt lt saccadic amplitudes lt x gt Ay lt diamecer gt CONDITION LABEL 1 condition value 1 CONDITION LABEL 2 condition value 2 Trial specific Message Command Format IV V CRI SACCADE srt start msg gt lt saccadic amplitude gt lt x gt lt y gt lt diameter gt Note If the location information of the saccade is not important set the values of x y and diameter as 1 Condition labels and their values are not required for the trial specific message command and optional for the pre trial message command if not specified the RT definition is applied to all conditions EyeLink Data Viewer 2002 2008 SR Research Ltd 98 Example MSG 329381 V RT SACCADE SYNCTIME 5 0 300 400 100 TYPE Normal In this example the RT end event is the occurrence of the first saccade with a minimum amplitude of 5 0 degrees of visual angle The saccade must fall within 50 pixels from the region center 300 400 7 4 4 Message
132. n events For a Data Viewing session that loads in several recording sessions only the first recording session will be exported in the recording event sequence output file 6 11 2 1 Fixation Events Fixation events are recorded in the format of e EFIX lt eye gt lt stime gt lt etime gt lt dur gt lt axp gt lt ayp gt lt aps gt lt xr gt lt yr gt lt ma gt lt jq gt This reports the eye used in the recording the time of the first and last sample 1n the fixation and computes the duration of the fixation in milliseconds The average X and Y eye position the type of position data is determined when the event was generated and the average pupil size area or diameter are reported The horizontal and vertical eye position angular resolutions in pixels per visual degree are reported next In addition the output contains information on whether the fixation has been manually adjusted lt ma gt and the ID and name of the interest area in which the current fixation falls lt 1a gt 6 11 2 2 Saccade Events Saccade events are recorded in the format of e ESACC lt eye gt lt stime gt lt etime gt lt dur gt lt sxp gt lt syp gt lt exp gt lt eyp gt lt ampl gt lt pv gt lt XTr gt lt yr gt This reports the time of the first and last sample in the saccade and computes its duration in milliseconds The X and Y eye position at the start and end of the saccade lt sxp gt lt syp gt lt exp gt lt eyp gt are
133. n for Fixation Location If checked use the X position to indicate the position of a fixation event in the temporal graph view otherwise use the Y position EyeLink Data Viewer 2002 2008 SR Research Ltd 141 9 9 Animation Preferences The parameters related to the animation playback preference settings are covered below a Inspector Memory Usa Enable Cyclopean Cursor For a binocular amp Data Qf Preferences recording enabling this option will display a meee cyclopean gaze cursor instead of two separate General gaze cursors in the animation view Data Loading Output f Analysis Right Gaze Cursor Color Left Gaze Cursor Color Data Fit bd n He pane Cyclopean Gaze Cursor Set the colors to be Overlay used to show the right left and cyclopean gaze Time Plot cursor The default settings can be changed by 6 ee clicking the corresponding cell and choosing a color from the palette or entering the value in RGB or HSB scales Enable Cyclopean C Right Gaze Cursor C Gaze Cursor Diameter Sets the diameter of the gaze eft Gaze Cursor cursor in pixels olopean Gare Cu Gaze Cursor Diemet P0 Trial Time Color Sets the color of the trial time code Trial Tire Color Trial Time x Position Trial Time Y Postion 5 Trial Time X Position Trial Time Y Position Trial Time Font Size h f idth d ane n Sets the x percent of screen width and y percent
134. n the settings used in the interest period filter see Figure 6 13 Ifthe interest period filter is set to Full Trial Period the start IP START TIME end IP_END_ TIME and duration IP DURATION of the interest period will be same as those for the recording period e START TIME END TIME and DURATION If the interest period filter is set to Reaction Time Period the start end and duration of the interest period will be same as those for the reaction time period If the user has created her his own interest period see section 6 4 1 and that interest period is used to filter events the output report will only do summary statistics variables marked with in the above table for those events falling within that period 6 5 4 Configuring the Trial Report EyeLink Data Viewer 2002 2008 SR Research Ltd 58 The Data Viewer also allows the user to configure the trial report similarly the fixation report saccade report and the interest area report The user can exclude some trials by entering a string in the Exclude Trial String edit box This string should be one message or part of a message within the scope of the trial recording see section 7 1 on defining the start and end of a trial that uniquely defines that subset of trials to be excluded In addition to enable correct loading of string text variables in some statistics software the Viewer also has an option of adding a pair of quotation marks for such v
135. n which the trial starts and ends for each condition of the experimental design Once a set of RT definitions has been created and initialized the RT start and end event information is available in both the trial view window and the inspector window 6 3 1 Reaction Time Manager The Reaction Time Manager is used to create edit or delete reaction time definitions for different experimental conditions The user can set parameters of a trial end event and specify condition values that must be matched for the RT definition to be applied to a given trial To configure reaction time definition 1 From the menus choose Analysis Reaction Time Manager Reaction Time Definition Manager Figure 6 5 Reaction Time Definition Manager In the reaction time manager dialog see Figure 6 5 the user can create a new reaction time RT definition by clicking the new H button on the left edit an existing RT definition by clicking on the button and remove an RT definition by clicking on the T button Users who have already had custom reaction time messages defined in the EDF file need to decide whether the customer RT messages or the RT definitions created here should take precedence when both of them are applicable for a particular trial If Override Custom Reaction time definitions box is checked the new RT definitions created through the Reaction Time Manager will take precedence otherwise the custom RT messages written in the EDF fi
136. nd ends after the trial starts or starts before the trial ends and ends after the trial ends eye in a binocular recording CURRENT FIX Y OTHER Y coordinate of the current fixation on the other eye in a binocular recording Note Similar analyses are done for the previous fixation variables beginning with PREVIOUS FIX and for the next fixation variables beginning with NEXT FIX EYE USED Which eye s data LEFT or RIGHT is used to create this report IP END TIME End time in milliseconds since EyeLink tracker EyeLink Data Viewer 2002 2008 SR Research Ltd 61 LE OOOO was activated of the interest period IP LABEL Label of the current interest period selected in the viewing session was activated of the interest period Trial time when the last button is pressed NEXT FIX ANGLE Angle between the horizontal plane and the line PREVIOUS FIX ANGLE connecting the current fixation and the previous next fixation see 5 2 NEXT FIX DIRECTION Direction Left Right Top Bottom relative to PREVIOUS FIX DIRECTION the current fixation in which the next previous fixation 1s located PREVIOUS FIX DISTANCE next previous fixation in visual degrees visual angle NEXT SAC ANGLE Angle between the horizontal plane and the direction of the next saccade see 5 2 NEXT SAC AVG VELOCITY Average velocity of the next saccade NEXT SAC DIRECTION Direction Left Right Top Bottom relative to the current fixa
137. nd saccadic amplitude as well as the reaction time calculated for the trial based on the reaction time definitions created for the Data Viewer session The Sample Output Report provides a columnar output of eye movement data for each eye sample in a trial Variables include the index of the sample in a trial time of the sample position x y velocity acceleration and pupil data of the current sample If appropriate target position messages are read from the EDF file the position velocity and acceleration data of the targets up to two targets can also be provided The user can also save the spatial overlay and temporal graph views into image files save the playback of the trial into a movie file or create a landscape view 1 e fixation map for a trial or for a group of trials with the same background image 1 7 Experiment Integration The EyeLink Data Viewer allows commands to be inserted directly into the EyeLink EDF file when an experiment is running This allows the experiment to be significantly integrated into the Data Viewer These commands are interpreted by the Data Viewer when the data file is loaded and automates several areas of the viewer functionality By using a set of predefined viewer commands the programmer of an experiment can inform the Data Viewer regarding a The image s to load for each trial s Spatial Overlay View b The Interest Areas to load for each trial c The Reaction Time Definitions to appl
138. ne either manually see section 5 1 2 or through the definition of some data filters For example the user may be interested in the fixations and saccades within the reaction time definition of a trial only 1 e between the onset of the search display and the press of the response button As a result those events prior to and following the RT definitions may be hidden from viewing and analysis output This can be achieved by applying a set of data filter in the preference EyeLink Data Viewer 2002 2008 SR Research Ltd 118 settings In the Inspector Window click the Preferences Tab and select the Data Filters node For the current example check the Hide Events outside RT definition and Hide Spanned Events check boxes If only fixations saccades and blinks are to be hidden check the Hide Eye Events Only otherwise all events falling outside the filter will be hidden Note By default if an event is hidden it will be removed from the temporal graph view spatial overlay view as well as the output report However if the field of Include Hidden Events in the General Preference Settings see section 9 1 1s checked hidden events can also be shown in the trial view windows Those events will be drawn in dashed lines 8 3 4 2 Merging and Drift correcting Fixations Temporally contiguous fixations can be merged see section 5 2 2 For example for the second trial of the current example the user may decide
139. nk data file that allow the viewer to automate some of the viewer configuration for a given data file or trial Examples of these commands include defining the image to overlay and specifying trial variables These messages can be written by the display experiment to the EDF file using the API function that allows the writing of a custom message to the EDF file Messages that make up the EyeLink data file protocol for the viewer are not added to the Message list that 1s created for viewing within the viewer tool Message commands are therefore invisible to the viewing windows and are only interpreted by the Viewer during application loading Important Do not use space characters in any component of a viewer message command the space character 1s used to tokenize and interpret all viewer messages Instead of using a space character within a message token use the _ character 7 1 Defining the Start and End of a Trial The viewer uses two special message commands to define what should be considered the start and end of a trial for the purpose of parsing the EyeLink data files 7 1 1 Trial Start Message Identifier Default TRIALID Description This message defines the start of a trial for the viewer This is different than the start of recording message START that is logged when the trial recording begins The viewer will not parse any messages events or samples that exist in the data file prior to this message The command identifier
140. non Remote eye tracker HTARGET X X position of the head target in camera coordinate for an EyeLink Remote recording Returns a missing value if the head target was missing or if the data was recorded with non EyeLink Data Viewer 2002 2008 SR Research Ltd 74 HTARGET Y HTARGET FLAGS IP DURATION IP END TIME IP LABEL IP START TIME LEFT ACCELLERATION X LE FT ACCELLERATION Y LEFT GAZE X LEFT GAZE Y LEFT INTEREST AREA ID LEFT INTEREST AREA LABEL LEFT IN BLINK LEFT IN SACCADE LEFT PUPIL SIZE LEFT VELOCITY X LEFT VELOCITY Y RESOLUTION X RESOLUTION Y RIGHT ACCELLERATION X EyeLink Data Viewer Remote eye tracker Y position of the head target in camera coordinate for an EyeLink Remote recording Returns a missing value 1f the head target was missing or if the data was recorded with non Remote eye tracker Flags used to indicate the head target tracking status if target tracking is ok otherwise error code for an EyeLink Remote recording Returns a missing value if the data was recorded with non Remote eye tracker Duration of the interest period in milliseconds End time in milliseconds since EyeLink tracker was activated of the interest period Label of the current interest period selected in the viewing session Start time in milliseconds since EyeLink tracker was activated of the interest period TRIAL LABEL Label of the trial Acceleration value in degree second sec
141. oS Buck did notr acHt newspapers or he would have krevyn that CI Trial 2 ii 103g ol i p n trouble was brewing notalone for but for every tidewater ap i 18 4 E NA Int crest Area templates dog viji m PThuscle amp VV ire OF hair fre ee oes cute to 26 0 SammBiego _Becatiso mer groping in the Arctic darkness had found 35 5 Saccade 20494ms Fe oo le en acter Geen jni saccade 20718ms a yello sia aaa aa sida ASPO al sic inal liis Saccade 21010ms werd koe ting the tid thousands of men were rushihg intethe T Saccade 21242ms Saccade 21446ms So ae ana the ere T Saccade 21678ms T Saccade 21886ms TP Saccade 22230ms T Saccade 22514ms TP Saccade 22770ms Peak Velocity 57 8 degrees sec Average Velocity 132 98705 degrees RT End Event Hidden False Manually Adjusted False Color Figure 5 5 Sample Spatial Overlay View of Saccade Events Saccade events see Figure 5 4 can be toggled on off in both the spatial overlay and temporal graph views by clicking the Toggle Saccade Event Visibility button A saccade is represented as an arrow in the spatial overlay view pointing towards the endpoint and as a colored solid line in the temporal graph view The following table lists the properties of a saccade event Those fields that are editable in the viewer are marked with an asterisk Average Velocity degrees per second RT End Event Wh
142. oes not need to be the full image path in the trial If no matching Image Name Mapping text was found for the trial in any IAS template then the default empty interest area set template will be used for the trial To illustrate the use of automatic trial 1mage interest area set association create a Data Viewer session and load in the sample picture EDF file File Import Data gt EyeLink File s and segment files test1 ias test2 1as test3 1as and test4 1as File gt Import Data Interest Area Template The second trial of the EDF contains the following image loading command message MSG 62817663 V IMGLOAD FILL images Sac blur jpg If the user wants to associate the test2 1as to Trial 2 first make sure that the Auto Select IAS for Trial property in the Output Analysis preference settings 1s checked Click on the test2 1as in the treeview and enter Sac_blur jpg case sensitive without quotes in the Image Name Mapping field Now the interest areas contained in test2 1as will be drawn on the Trial View Window for Trial 2 EyeLink Data Viewer 2002 2008 SR Research Ltd 39 o x g Inspector E EP Data gi Preferences jor i H g T MAF E Untitled evs Ha picture F CI Trial 1 CI Trial 2 CI Trial 3 Interest Area Templates Ej m po BST a P test jas The house testi jas Was approached by gravelled driveways
143. of screen height coordinates of the trial time code Trial Time Font Size Sets the font size of the trial time code Display Frame Number If checked displays the frame number of the video being played EyeLink Data Viewer 2002 2008 SR Research Ltd 142
144. of the files that are used to build VisualSearch Those that are the same as for the Picture template are marked with an asterisk Those files that have been modified are discussed in the following sections w32 demo h Declarations to link together the template experiment files Most of the declarations in this file can be used in your experiments w32_script_main c WinMain function setup and shutdown link and after w32_demo main c graphics open EDF file open a script file containing the trial randomization information w32 demo window c Implements the full screen window used for calibration validation and presentation This file is unchanged for all templates and can be used without changes in your experiments w32 script trials c Performs system setup at the start of each block and then after w32 picture trials c runs the trials with information read from the script file Handles standard return codes from trials to allow trial skip repeat and experiment abort w32_ bitmap trial c Implements a trial with simple graphics that can be drawn in one screen refresh and therefore doesn t need display blanking You should be able to use this by replacing the drawing code message code and handling any subject responses w32 text support c Implements a simple interface for font creation and EyeLink Data Viewer 2002 2008 SR Research Ltd 105 printing This is a support module that you can link into your experimen
145. on Participants in both conditions performed two search tasks In a single feature SF task the target stimulus shared one feature with each of the distractors whereas in a two feature TF task it shared two features with each distractor Williams and Reingold 2001 investigated whether the conjunction search tasks are guided by certain feature s shared between the target and distractors By examining the spatial distributions of the fixations they found that participants were more likely to fixate on those distractors sharing color SF task or color and shape TF task with the target This was a robust finding being observed across participants across saccades of different amplitudes and sequential position and following short and long latencies to move These investigators also found that the extent to which participants made use of shape information increased with discriminability 8 2 Programming The current experiment includes three individual projects Gen _IAS for creating interest area set files Gen_Rnd for generating randomization script files and VisualSearch for running the actual experiment and integrating the Data Viewer functionalities 8 2 1 Creating Interest Area Set Files The Gen_IAS project creates interest area set files for the current visual search displays The main function in the Gen_IAS c file marks the beginning of program execution It is used to create 48 replicas of test trials 3 for pr
146. on to enter the current interest area End time of the saccade that last landed within the ME current interest area Start time of the saccade that last landed within the IME current interest area IA LEFT Left side pixel position of non freehand IA IA LEGAL A trial is considered legal 1 e IA LEGAL 1 only if the first fixation in interest area N was preceded by a fixation in interest area N 1 This variable is relevant for experiments that run in a contingent display paradigm as it ensures that readers could see the target area before actually lending in it IA MAX FIX PUPIL SIZE Maximum pupil size among all fixations in the interest area Note this measure does not represent the maximum pupil size within a fixation IA MIN FIX PUPIL SIZE Minimum pupil size among all fixations in the interest area Note this measure does not represent the minimum pupil size within a fixation IA REGRESSION IN Whether the current interest area received at least one regression from later interest areas e g later parts of the sentence 1 if interest area was entered from a higher A_ID from the right in English 0 if not IA REGRESSION IN COUNT Number of times interest area was entered from a higher IA_ID from the right in English EyeLink Data Viewer 2002 2008 SR Research Ltd 67 IA REGRESSION OUT Whether regression s was made from the current interest area to earlier interest areas e g previous parts of t
147. ond of the left eye along the x axis Acceleration value in degree second second of the left eye along the y axis Left eye gaze coordinate along the x axis Left eye gaze coordinate along the y axis Index of the interest area in which the left eye sample falls Label of the interest area in which the left eye sample falls Whether the left eye is in a blink Whether the left eye is in a saccade Left eye pupil size of the current sample Velocity value in degree second of the left eye along the x axis Velocity value in degree second of the left eye along the y axis Horizontal angular resolution in screen pixels per degree for the sample Vertical angular resolution in screen pixels per degree for the sample Acceleration value in degree second second of the right eye along the x axis 2002 2008 SR Research Ltd 75 Acceleration value in degree second second of the right eye along the y axis Right eye gaze coordinate along the x axis Right eye gaze coordinate along the y axis sample falls Label of the interest area in which the right eye sample falls RIGHT IN BLINK Whether the right eye is in a blink RIGHT IN SACCADE Whether the right eye is in a saccade RIGHT PUPIL SIZE Right eye pupil size of the current sample eye along the x axis Velocity value in degree second of the right eye along the y axis If the EyeLink button box is pressed this records the ID of the EyeLink button numbe
148. or IA color Button Color Message Color Reaction Time Start Color Reaction Time End Color and Selection Square Color Set the colors to be used to show fixations saccades blinks interest areas button events messages the start end of reaction time calculation and the event selection square These settings can be changed by clicking the corresponding cell and choosing a color from the palette dialog or entering the value in RGB or HSB scales Unselected Stroke Width and Selected Stroke Width Pixel width for the selected and unselected events Adjust Saccades with Fixations Whether or not to adjust saccade parameters when the fixations are shifted or merged Batch Drift Correction Error Threshold The maximum tolerable deviation in the Y dimension or the X dimension 1f the next field 1s unchecked for a fixation from the mean of the group of fixations to be drift corrected in a batch If any fixations within the group exceeds this threshold batch drift correction cannot be performed Batch Drift Correction Y X false If checked chooses the Y dimension for batch drift correction If unchecked X dimension is checked Include Fixation in Single IA In case of overlapping interest areas whether or not to limit the assignment of a fixation to one interest area the interest area with a smaller EyeLink Data Viewer 2002 2008 SR Research Ltd 135 ID only Auto Select Fixation in Selected IA When an inter
149. or the selected fixations connects temporally contiguous fixations ample Trace Granularty ample Tick Width Sample Trace Granularity If the sample visibility is toggled on shows every nth sample by default n 5 isplay 14 isplay Fixation Duration ample Tick Period aa for every nth sample by default n aximum Fixation Circle inimurn LA Size ze SORT of Fix Dur t V Sample Tick Period Draws a circular tick z 20 Widely spread ticks indicate high saccade velocity Inuraurn Fixation Circle ackground Color aximum Graphics Corr t Overlay Image Chan fe Sample Tick Width Diameter in pixels of the sample ticks Minimum IA Size Minimum width of an interest area Display IA If selected shows percentage of trial dwell time spent on the selected interest area EyeLink Data Viewer 2002 2008 SR Research Ltd 137 Use SQRT of Fixation Duration for Circle Size Uses the square root of fixation duration to calculate the width of the fixation circle if checked Fixation Circle Scalar Maximum Fixation Circle Width and Minimum Fixation Circle Width If the above Use SQRT of Fixation Duration for Circle Size option is not used use Fixation Circle Scalar to define a scalar for fixation circle width calculation The maximum and minimum circle widths are set with the Maximum Fixation Circle Width Minimum Fixation Circle Width elements Background Color Background color for the spatial over
150. ore precise IA selection click on the Custom Interest Area Set node of the trial in the tree view and select the interest areas from the list panel Alternatively you can toggle off the eye movement events first make the interest area selection and then toggle the eye movement events back on 9 8 11 Moving an Interest Area An interest area can be moved by following these steps 1 Put the mouse cursor over the Interest Area 2 Hold the ALT key down 3 Press the left mouse button 4 Drag the IA to the desired location 5 Release the mouse button 9 8 12 Resizing Rectangular and Elliptic Interest Areas A rectangular or elliptic interest area can be resized by following these steps 1 Hold the ALT key down 2 Place the mouse over the border to be dragged the arrow cursor changes into a sizing cursor 3 Press the left mouse button and drag the border to the desired location 4 Release the mouse button To carry out a more precise adjustment for a rectangular or elliptic interest area 1 Select the interest area to move or adjust 2 In the property panel of the interest area select the entry for Left and type in the desired x coordinate of upper left corner 3 Select the entry for Top and type in the desired y coordinate of upper left corner 4 Select the entry for Right and type in the desired x coordinate of bottom right corner 5 Select the entry for Bottom and type in the desired y coordinate
151. ote that results for saccades smaller than 1 are not reported because of insufficient data points in some cells EyeLink Data Viewer 2002 2008 SR Research Ltd 124 Table 1 Average percent of fixations by discriminability and search task for the first fixations following a short below median and long above median initial saccadic latency Condition Task LD SF N 8 TF HD SF N 8 TF CS CO SO Short Latency SEM 64 504 3 728 19 378 1 705 16 119 ZS 34 059 2 362 41 993 1 797 23 948 2 849 50 863 6 898 27 082 3 290 22 055 4 678 39 978 2 569 33 914 1 825 26 109 3 187 Long Latency SEM 70 765 3 619 15 419 2 587 13 816 2 665 45 268 3 849 40 349 2 145 14 383 2 186 53 972 6 167 26 924 4 935 17 104 1 976 54 176 5 044 29 265 3 852 16 558 2 434 Table 2 Average percent of fixations by discriminability and search task for the first fixations second fixations and all fixations Condition Task LD SF C N 8 S O TF CS CO SO HD SF C N 8 S O TF CS CO SO Y o 67 467 17 761 14 772 39 742 40 948 19 309 53 446 27 060 19 493 47 103 31 606 21 290 First Fixations SEM 3 204 2 008 2 216 2 299 1 135 2 146 6 096 3 668 3 104 3 555 2 141 2 476 A 70 893 16 377 12 729 54 386 35 393 10 222 56 509 29 872 13 619 79 496 13 146 7 357 Second Fixations SEM 2 692 1 641 1 765 3 192 3 240 1 614 4 394 3 564 1 804 3 296 2 378 1 324 All Fixations SEM
152. ould place certain messages into the EDF file to enable Data Viewer to process the files more efficiently Examples of these commands include defining the image to overlay specifying trial variables defining a start time of RT definition etc These messages will be timestamped with an accuracy of 1 millisecond from the time sent and can be used to mark important events such as display changes If the user forgot to write these messages when the experiment was created these messages can still be imported from a text file The loaded message list file must be an ASCII file and each line must be a valid EyeLink MSG line in the format of MSG EDF time Offset Message text EyeLink Data Viewer 2002 2008 SR Research Ltd 31 where e EDF time must be an integer If this field is positive it is assumed to be the absolute EDF timestamp to be used for the message e g a value of 62798072 for EDF time field will place the message in a trial which started after 62798072 and ended before 62798072 If EDF time is negative the EDF time trial index of the message in the EDF file A value of 1 would mean the first trial in the file and 4 would mean the 4th trial in the file In this case the message EDF time is set to the start of the trial time in this case e Offset is optional and must be an integer if specified Offset is subtracted from EDF time to generate the real message time For example a message line of MSG 2435806 14 V APLAYST
153. perties as Defaults EyeLink Data Viewer 2002 2008 SR Research Ltd 127 9 1 General Preferences The general preference setting covers the following elements res Inspector Use Right Eye if Binocular For a binocular E gt Data a Preferences Preferences Data Loading Output Analysis Data Filters Data Views Use Right Eye if Biri Include Hidden Events Display samples Display Fixations Display saccades AAI az Display IAs Defaut Viewing Sessi D Program Filestor Re Default Data File Direct DoPrograrn FilesiSR Re Defaut IA File Directory D Program FilesisR Re Defaut Image Directory D Program FilesisR Re Defaut Display Width 1024 I Defaut Display Height BS recording which eye s data is to be displayed right eye if checked left eye if unchecked Include Hidden Events Whether or not to include hidden events in Trial Views and Output Reports Display Samples Display Fixations Display Saccades Display Blinks Display Messages Display Buttons and Display IAs Whether or not to display samples fixations saccades blinks messages buttons and interest areas when the data file is first loaded by default only fixations and interest areas are displayed Default Viewing Session File Directory Default Data File Directory Default IA File Directory Default Image Directory and Default Report Directory Se
154. r The index of the sample in the trial Message text printed out during the current sample Acceleration value in degree second second of the target along the x axis Acceleration value in degree second second of the target along the y axis Velocity value in degree second of the target along the x axis Velocity value in degree second of the target along the y axis TARGET VISIBLE Whether the target is visible during the current sample To support the retrieval of target position from a sample report the target position data must be written according to some format see section Protocol for EyeLink Data to Viewer Integration gt Target Position Commands TARGET X Target gaze position on x axis TARGET Y Target gaze position on y axis TIMESTAMP The time stamp of the sample in milliseconds since EyeLink tracker was activated TRIAL LABEL Label of the trial TRIAL START TIME The start time in milliseconds since EyeLink tracker was activated of the trial EyeLink Data Viewer 2002 2008 SR Research Ltd 76 VIDEO FRAME INDEX Index of the video frame that was visible at the sample time Note that all VIDEO variables are applicable to SceneLink recordings or some Experiment Builder recordings only For SceneLink recordings please check out the Data Loading Preference Settings VIDEO NAME Name of the video frame that was visible at the sample time Note All AVERAGE measur
155. r or click the right mouse button and select delete If an event is deleted it will be permanently removed from the temporal graph view spatial overlay view as well as the output reports and cannot be undeleted In addition deleting a fixation or saccade event will EyeLink Data Viewer 2002 2008 SR Research Ltd 21 have an impact on other temporally contiguous events For example deleting a fixation will merge the saccades on either side of the fixation into one saccade Similarly deleting one saccade will merge the fixations on either side of the saccade into one big fixation 5 2 Fixations To examine the fixation information in the data file first make sure that the fixation events are visible This is done by ensuring that the Toggle Fixation Event Visibility button in the application desktop toolbar is selected evEyeLink Data viewer 5 x File Edit Analysis Window Help lejals x e es si8 Molly Melese wmaw J o Trial View text Trial 1 5 Toggle Fixation Event Visibility 5 x Data Preferences be PA A eg A Ra E 9 Untitled evs A EB Buck ddot r ad thecnewspaper er or he Would have knowin that Sd Trial ues a ial las trouble wa brewing a n ERA for Aims tt but for eee tide lt water interest Area Templates dog trong Gf muscle ene wittnwarm jong hair from Puge ound to SamDiegd Because men Groping nha PEE datkhess
156. r a Data Viewer session The Fixation Output Report generates one row for each visible fixation within the Data Viewer A set of output variables can be selected with each variable output as a column in the report Fixation report variables include start and end time duration average position interest area identifier etc A set of relative variables is also available including the previous and next fixations position angle distance and direction The Saccade Output Report generates one row for each visible saccade within the Data Viewer A set of output variables can be selected with each variable output as a column in the report Saccade output report variables include start and end time start and end position amplitude angle direction average and peak velocity etc A set of relative variables is also available including the previous and next saccades start and end position etc EyeLink Data Viewer 2002 2008 SR Research Ltd 3 The Interest Area Output Report generates one row for each interest area in every trial loaded in the Data Viewer Variables include the interest area identifier label fixation index list number fixations summed dwell time and proportions of fixations and dwell time in the interest area relative to the trial The Trial Output Report generates one row of data for each trial within the Data Viewer Variables include the count of each event type visible within the trial the average fixation duration a
157. r supports a set of interest area commands that inform the viewer what interest areas to create by default for a given trial Trials that have interest area commands specified in the data file have a custom interest area set created when the data is loaded containing the specified interest areas All interest area commands start with the AREA token and are followed by a one word sub command 7 3 5 1 Rectangular Interest Area Identifier Default RECTANGLE Description This message specifies the attributes of a rectangular interest area for the trial Each trial can have a set of such rectangular interest areas Format IV TAREA RECTANGLE lt id gt lt left gt lt top gt lt right gt lt bottom gt label string Note The label string parameter is optional Example MSG 2740540 VIAREA RECTANGLE 154 547 4410 585 449 7 3 5 2 Elliptic Interest Area Identifier Default ELLIPSE Description This message specifies the attributes of an elliptic interest area for the trial Each trial can have a set of such elliptic interest areas Format IV TAREA ELLIPSE lt id gt lt left gt lt top gt lt right gt lt bottom gt label String EyeLink Data Viewer 2002 2008 SR Research Ltd 93 Note The label string parameter is optional Left top right and bottom refer to the x y coordinates of the top left and bottom right corners of the bounding rectangle Example MSG 2740540 TV IAREA ELLIPSE 154 547 410 585
158. rea to which the current fixation 1s assigned and the label of that interest area In addition we also planned to examine whether such a distribution is influenced by the amplitude of the previous saccade PREVIOUS SAC AMPLITUDE and whether for the first fixations the distribution was influenced by the initial saccadic latency of the trial in the current example the initial saccadic latency of the trial can be calculated as the PREVIOUS SAC START TIME for the first valid fixation in the trial e Gutput Report X Available Output Variables Selected Gutpuk variables PREVIOUS SAC INDEX PREVIOUS SAC 15 RTEND PREVIOUS S amp C NES amp REST_END_INTEREST_ A PREVIOUS S4C NE amp REST_ END _INTEREST_ A PREVIOUS S4C NE amp REST_START_INTEREST PREVIOUS S40 NE amp REST_START_INTEREST PREVIOUS S4C PEAK VELOCITY PREVIOUS S4C SELECTED PREVIOUS S4C START INTEREST AREAS PREVIOUS SAC START_ i F F PREVIOUS 54C START Exclude Trial String TRIGL_ FIXATION TOTAL T Include Hidden Events in Relative variables ODC santa COC eSRL AOC P Treat Hidden Events as Missing Values in Relative Variables TRIAL_FILENAME TRIAL_LABEL ihe CORRENT_FIs INDE CORRENT_FIs_DURATIOMN ha COURRENT_FIs_MEAREST_INTEREST_AREA COURRENT_FIs_MEAREST_INTEREST_AREA_ L PREVIOUS _ SAC AMPLITUDE PREVIOUS _ 5470 ST4 amp R7_TIME M Use Quotes 3 Around String Text Variables Reset Cancel Next Figure 8 14 Obtaining a Fixat
159. riable Manager The following rows list the corresponding values for the variables in each individual trial To change the value for a particular cell double click on the current value type in the new value DO NOT include quotes for text strings and press Enter to register the change Note presumably the user would load EDF files of the same experiment with the same condition labels into one viewing session Loading EDF files containing different condition labels from each other may result in some unexpected findings 6 1 3 Trial Grouping Trial condition variables are important for identifying one specific trial or grouping trials tested under the same experimental condition Thus instead of going through each of the individual trials a trial grouping mechanism can be applied to manipulate those trials collectively For example practice trials can be removed from the viewing session in a batch interest area templates can be applied to those trials using the same search display EyeLink Data Viewer 2002 2008 SR Research Ltd 44 and potentially a landscape view can be created for the same display image with data collected from several subjects to identify the informative parts of the display By default the Data Viewer group all of the trial by data file To regroup trials within a viewing session select the viewing session icon click the right mouse button and choose the Trial Grouping option In the following
160. rial In the current example the TRIALID message included in the do_script trial function defines the start of a trial for the Viewer The Viewer will not parse any messages events or samples that exist in the data file prior to this message The TRIAL VAR DATA message specifies the list of trial variable values for the trial see section 7 3 1 Note that the list of trial variable values must be in the same order as was specified in the TRIAL VAR LABELS command for the viewer to properly match the variable label with the variable value Given trial file name execute trials Returns trial result code lt filename_inf gt name of the trial ias filename int do script _trial char filename_inf int i 0 int presence target presence 0 for absent and 1 for present int setsize number of items in a display INE features number of features shared between the target and distractors 0 for single feature 1 for two feature int practice Whether the trial is a practice trial char text 200 token char image fn 200 image path 200 string to store the file and path names of the image Always send a TRIALID message before starting to record eyemsg printf TRIALID s filename inf Find the useful trial filename information from the string removing the directory name strcpy text filename inf token striok text YTS token strtok NULL EyeLink Data Viewer 2002 2008 SR Research Ltd
161. rial Condition Variable PRESENCE Present Start Time Message Text SYNCTIME Button Number 4 Button State selected A selected RT definition can be edited by clicking on button and removed by clicking thelill button Once all of the RT definitions have been finalized close the Reaction Time Definition Manager dialog In the following Initialize All RT Events dialog click the Yes button to apply the RT definitions For each trial if a matching reaction time definition is found a red RT symbol is displayed near the end event in the spatial overlay view of the trial view window In the temporal graph view a green line is drawn at the time when the start message is recorded and a red line 1s drawn at the time when the end event occurred In the event list of the Inspector window the RT End Event field is automatically checked for the end event that matches the reaction time definition 8 3 4 Manipulating Events The EyeLink Data Viewer supports several forms of event manipulation including hiding deleting merging and drift correction The current tutorial focused on hiding events merging and drift correcting fixations see Section 5 Working with Events samples and Interest Areas for detailed documentation of all event manipulations 8 3 4 1 Hiding Events Within each trial some events may be hidden from analysis so that the user can focus on a subset of data in each trial Event hiding can be do
162. rials c file of the template see the Table Data Viewer Functionality Message Commands Trial Variable Labels eyemsg printf TRIAL VAR LABELS TRIAL WORD Trial Variable Values eyemsg printf V TRIAL VAR DATA s trial word num 1 7 5 9 Other Templates Since the Broadcast and Comm listener templates do not produce EyeLink data recording no change has been made in those templates to support Data Viewer analysis EyeLink Data Viewer 2002 2008 SR Research Ltd 103 8 Tutorial Visual Search The current tutorial aimed to create an experiment following Williams and Reingold 2001 and perform similar analyses with the EyeLink Data Viewer 8 1 Project Background Information In a recent study by Williams and Reingold 2001 eye movements were monitored during the performance of a visual search task Display items were created by combining features from three stimulus dimensions color red vs blue shape C vs T or E vs F and orientation normal vs rotated Across trials the target counterbalanced across subjects was either present or absent Each displays consisted of 6 12 or 24 items Stimulus discriminability was manipulated for the shape dimension with half of the participants seeing displays of E s and F s low discriminability condition whereas the other half of the participants seeing displays of C s and T s high discriminability conditi
163. riting if discriminability sprintf image path Images HD c c c target color B R targ t shape ThetC target orientation R N else sprintf image path Images LD c c c target color B R target shape Fot E target orientation Ri N IMGLOAD command is recorded for EyeLink Data Viewer analysis It displays a default image on the overlay mode of the trial viewer screen Writes the image filename path info eyemsg printf V IMGLOAD FILL s s image path image fn The current experiment uses the bitmap _save_and_backdrop function to transfer the trial bitmap to the tracker PC as backdrop for gaze cursors This function also saves the bitmap as a JPEG file in the specified path images Please note that the file EyeLink Data Viewer 2002 2008 SR Research Ltd 108 saving option can be manipulated so that the existing files can be either overwritten set the sv_options as 0 or not overwritten SV_NOREPLACE Save bitmap and transfer to the tracker pc Since it takes a long to save the bitmap to the file the value of sv options should be set as SV NOREPLACE bitmap save _ and backdrop bitmap 0 0 0 0 image fn image path SV_NOREPLACE 0 0 BX MAXCONTRAST is eyelink2 0 BX GRAYSCALE 8 2 4 4 Interest Area Similarly interest areas can be created for each trial specifying the x y coordinates for each individual display item as well as its label In
164. rocess by pressing the Cancel button EyeLink Data Viewer 2002 2008 SR Research Ltd 70 X r Creating Report 1 Session D Trial 1 14 20 TT LI Cancel Figure 6 14 Progress Dialog Box Displayed when Creating the Interest Area Report 6 8 3 1 Fixation Sequence Analysis Variables A FSA COUNT and IA FSA DURATION are used primarily for fixation sequence analysis 1 e examination of the frequency of saccades directed from the current interest area to all interest areas If there are N interest areas in a trial this will generate N columns in the output report with column labels being IA FSA COUNT 1 to IA FSA COUNT N for counts and A FSA DURATION 1 to IA FSA DURATION N for duration outputs Each column in the output file reports number of fixations coming to one particular interest area from each of all possible interest areas Each row reports number of fixations starting from the current interest area and ending at each of the interest areas when Fixation Skip Count in the Output Analysis preference settings is set to 1 Interest Area 1 2 3 A 5 6 Fi Text He said Truth is a pathless land Fixation Sequence 1 2 3 gt 45 IA FSA_ IA_FSA_ IA_FSA_ IA_FSA_ IA_FSA_ IA_FSA_ IA _FSA_ COUNT_ COUNT_ COUNT_ COUNT_ COUNT_ IMME COUNT_ ID Le meo f ra fps Lan sian fo fs a M o A r C oF Fo Fo T 7 lan jo jo Jo o Jo H Jo EyeLink Data Viewer 2002 2008 SR Research Ltd
165. s all fixations on the current interest area interest area N the current interest area interest area IA FIRST FIX PROGRESSIVE Checks whether later interest areas have been visited before the first fixation enters the current interest area 1 if NO higher IA ID in earlier fixations before the first fixation in the current interest area 0 otherwise IA FIRST RUN DWELL TIME Dwell time 1 e summation of the duration across all fixations of the first run within the current interest area interest area first run of the current interest area UNT run of the current interest area interest area ME current interest area TIME the current interest area current interest area EyeLink Data Viewer 2002 2008 SR Research Ltd 66 IA FIXATION COUNT Total fixations falling in the interest area IA _ FSA COUNT The number of fixations fixation N which started in the current row of interest area with fixation N fixation skip count ending in the current column of interest area IA FSA DURATION The summed duration for all fixations fixation N which started in the current row of interest area with fixation N fixation skip count ending in the current column of interest area IA GROUP Group label for the current interest area IA ID Ordinal ID of the current interest area IA LABEL Label for the current interest area Duration of the last fixation event that was within N the current interest area Start time of the last fixati
166. s parts of the sentence prior to leaving that interest area in a forward direction Therefore the transition from F5 F6 makes this flag true for the interest area 6 labeled as pathless IA REGRESSION IN checks whether a given interest area received at least one regression from later parts of the sentence Therefore this is true for both interest areas 3 truth F5 F6 and 6 pathless F9 gt F10 6 9 Sample Output Report Sample output report provides a columnar output of eye movement data for each eye sample in a trial The sample report option will not be available if the samples are not loaded into a viewing session As in the other reports sample output report only outputs samples that fall within the active interest period for the trial 6 9 1 Loading Samples into a Viewing Session Version 1 7 of Data Viewer introduced a change to optimize the viewer performance by not loading the samples by default see revision history To make sample data available to a viewing session you will need to first change the data loading preferences and then reload the EDf file 1 Before loading any EDF files please go to Start gt Programs gt SR Research gt EyeLink gt Data Viewer to start the software 2 Once the application starts up click Preferences tab and go to Data Loading preferences Check the Load Samples option If you want this changes to be persistent over future viewing sessions you may
167. s release as the reaction time end event Select the intended button ID from the Button Number combo box and choose the button state button press or release Message Event This will treat the first occurrence of a matching message as the end event for reaction time calculation In the Message Text edit box type in the message string DO NOT include quotes for text strings Fixation Event This will end the trial by the appearance of a specific fixation In the edit boxes fill in the minimum fixation duration in millisecond required as well as the xy coordinates of the center of the fixation region and the diameter of the region Saccade Event This will end the trial by the occurrence of a specific saccade Fill in the minimum saccadic amplitude in degrees of visual angle required as well as the xy coordinates of the region center and the diameter of the saccade region 4 Once all the desired RT definitions have been set arrange the order of the definitions by using the and buttons in the Reaction Time Definition Manager dialog This operation is important only when more than one RT definition can be met for a single trial Always put specific definitions before general ones 5 Close the Reaction Time Manager dialog This will apply the reaction definitions to all trials If there are lots of trials in a viewing session this may take some time to finish 6 Ifthe user thinks that the current RT definitions ar
168. settings from the Data Filter preference If the Merge Nearby Fixations option is checked a fixation with a duration shorter than the value set in the Fixation Duration Threshold will be merged with a neighboring fixation if the latter 1s within the distance set by the Fixation Merging Amplitude Threshold 2 Four stage Fixation Cleaning Important This option was not intended for all users For some reading studies the users may want to apply a more refined fixation cleaning algorithm This can be done by select the intended Trial node or Recording session node click on the right mouse button and select the Clean option Clean Data E Stage 1 Stage 2 Stage 3 Duration Threshold feo fao fian Distance Threshold E h 25 stage 4 Durations Minirnurn h 40 haxirmnum eoo Delete Fixations Outside Interest Areas Start EyeLink Data Viewer 2002 2008 SR Research Ltd 26 ii iii iv v Figure 5 4 Options for Fixation Cleaning STAGE 1 For each interest area Data Viewer checks for each fixation whether its time duration is shorter or equal to the duration threshold If not the current fixation will not be cleaned otherwise Data Viewer further checks the duration and distance of the fixation immediately before and after the current fixation The fixation will be merged to the neighboring fixation 1f its duration is longer than the threshold value and its distance along the x axis in degrees from the
169. t Interest Area Template EyeLink Data Viewer 2002 2008 SR Research Ltd 38 2 Inthe Load dialog box browse to the location of the interest area file 1as that you want to import and select it 3 Click Load and the tree view panel will be updated 5 8 7 Using Interest Area Templates If several trials use the same set of interest areas an interest area template if already loaded can be used see section 6 1 3 on applying an interest area template to a group of trials To apply an interest area template 1 Click on the viewing session icon 4 and perform trial grouping if necessary 2 In the tree view panel of the data tab select the trial group onto which the interest area template is loaded 3 In the property panel of a selected trial or trial group find the entry Interest Area Set and select the target interest area template 5 8 8 Automatic Trial Image Interest Area Set Association If Auto Select IAS for Trial property in the Output Analysis preference settings is true any value in the Image Name Mapping field of the interest area set will be used to automatically associate the interest area set to trials If the last Data Viewer image load command entered in a trial contains an image name that contains the Image Name mapping text of the interest area template then the interest area set 1s associated with the trial Please note that the matching is case sensitive although the Image Name mapping text d
170. t default directories for accessing viewing session files data file loading interest area images loading saving and data output These settings can be changed by clicking on the current values and choosing a default directory from a Set window Note changes to these preference settings only take effect on files loaded after the change Default Display Width and Default Display Height Set display width and height to enable the Data Viewer to run properly if DISPLAY COORDS GAZE COORDS message is not found in the EDF file otherwise these preferences are ignored EyeLink Data Viewer 2002 2008 SR Research Ltd 128 9 2 Data Loading Preferences Data loading preference settings consist of the following parameters a Inspector Memory Usage s I GP Data wf Preferences Preferences General l_ Data Loading Lal Output l Analysis l_ Data Fitters a Data Views Load Samples F Load Fixations M Load Saccades Fj Load Blinks m Load Messages 1 ca lLoad Buttons Trial Load Start Messa TRIALID Trial Load End Message TRIAL RESULT All Trial Variable Label TRIAL_VAR_LABELS All Trial Variable alue TRIAL_WAR_DATA Single Trial Variable M RIAL VAR Target Position String TARGET POS Exclude Message Stri Enable SceneLink Gaz 7 Generate SceneLlink F Load Samples Load Fixations Load Saccades Load Blinks Load Messages Load Buttons Allow the loa
171. t Areas The visibility of interest areas can be toggled on off by clicking the Toggle Interest Area Visibility button Fl To create an interest area 1 Select the Interest Area shape that you want to create from the Application Desktop toolbar o Rectangular Interest Area Shape is active O Ellipse Interest Area Shape is active FreeHand Interest Area Shape is active For rectangle and elliptic interest area shapes see Figure 5 10 2 Hold down the left mouse button in the top left corner of where you want the interest area to be created 3 Drag the mouse down to the right until the selection region covers the area that you want to select 4 Release the mouse button 5 Enter the name of the Interest Area and press Enter 6 Repeat steps 2 6 to create more interest areas of the same type Press the Selection mode icon R from the Application Desktop toolbar to end creating interest areas For FreeHand interest area shapes 2 Double click the left mouse button on the first point of the shape to create 3 Move the mouse to the second point and double click the mouse again A line joining the points should be displayed 4 Repeat step 3 for each point of the freehand shape EyeLink Data Viewer 2002 2008 SR Research Ltd 36 5 Press the ENTER key when you have specified all points you wish to create The first and last points of the interest area will be joined by the program Note that you can cancel the creation o
172. t Report nenosssssseooseeeeennennnnnnnsssssssssseeen Ii 6 10 2 Variables in the Message Output Report cc ccesssssssesseeeeeeeeeeeeeeees 71 6 11 Recordio Event Sequence Data rosrarinir iiri aa a E E S 80 6 11 1 Obtaining a Recording Event Sequence Data cece eccccccceceeeeeeeeeeeees 80 6 11 2 Formats of the Recording Event Sequence Data uu 80 6 11 2 1 Fraton EVENS sissies tscaiasaduiedes aneis aces AE EAS 81 6 11 2 2 PCO AGC le We Noea e E E 81 6 11 2 3 Bt Ke EVOM Scaieni E TAAR 82 OIL24 Messate EVIS er n aad enteral ta eases 82 6 11 2 5 BUON E VCS neo neat lessee eee secu test annne ee eleueaets 82 7 Protocol for EyeLink Data to Viewer Integration ccccccccsssseeceececeeeeeeeeeeeaaaees 83 7 1 Defining the Start and End of a Irnialssruseninee e N 83 7 1 1 ial Stark Mossad cuon saan ee ole aan alerts eee 83 7 1 2 PARE NUM S SAO aris ste tera A E 84 k2 Pelna Messa COmMmMaiNd Sonina A O NA 84 T2 Trai Vanable Labe zresa a EE 84 IR Display Cordat Seenen kain n E EEE AS 85 T2 TEA COUN Siac e A 85 7 3 drialIViessace Command Sene enii e T A mecentss 86 7 3 1 rial Varable Valus aaa a a ATE 86 R32 Sinole Trial Variable Messace TOkeNeten teia seer e 86 7 3 3 DAMA CSAC OMIA S E E EAE I E AA E EA 87 7 3 3 1 Image Loading Fill Full Screen cc a 87 T332 Image Loading Lop eit aii stectasscetarn nt E ea nnd devotee teense 88 T 3 3 3 Amage Loading Centered sss ce os Sade cadena dusatponedeavsncacdvstetneadssndiav
173. t be merged 2 Press CTRL key to select the intended interest areas 3 Click right mouse button to bring up a popup menu select Merge from the list EyeLink Data Viewer 2002 2008 SR Research Ltd 42 6 Exporting Data One of the ultimate goals of the EyeLink Data Viewer is to extract useful eye movement information and export the data to a text file that can be processed by most statistical analysis software Currently the Data Viewer supports five kinds of outputs trial reports fixation reports saccade reports interest area reports sample output reports and recording event sequence data 6 1 Managing Trial Variables The Trial Variable Manager Figure 6 1 and the Trial Variable Value Editor Figure 6 2 allow the user to review the currently available variables to assign a default value for the variables to create or remove variables and to change the variable values on a trial by trial basis 6 1 1 Trial Variable Manager x Analysis Variables Selected Variable Label CONDITION Default Value Close Figure 6 1 Trial Variable Manager The Trial Variable Manager Dialog activated by pressing Analysis Trial Variable Manager from the menus lists the filename DATA FILE and other variables imported from the EDF file if the TRIAL VAR LABELS command is used PAGE in this case see Section 7 2 1 on how to define new trial variable labels To assign a default value to one variable click on the var
174. t corners of rectangle Example MSG 9441901 V DRAWBOX 0 255 0 200 300 400 500 This draws a green rectangle frame with the top left corner at 200 300 and the bottom right corner at 400 500 7 3 4 4 Drawing a Filled Rectangle Identifier FILLBOX Description This command draws a filled rectangle with the color specified by the red blue green integer values specified in the command Each RGB value should be an integer between 0 and 255 Format IV FILLBOX lt red gt lt blue gt lt green gt lt top gt lt left gt lt right gt lt bottom gt Note Left top right and bottom refer to the x y coordinates of the top left and bottom right corners of rectangle Example MSG 9441901 V FILLBOX 0 0 255 400 500 500 600 This draws a rectangle with the top left corner at 400 500 and the bottom right corner at 500 600 The rectangle is filled with the blue color 7 3 4 5 Drawing a Fixation Point Identifier FIXPOINT Description This command draws a fixation point at a specified position Format EyeLink Data Viewer 2002 2008 SR Research Ltd 91 IV RIXPOINT lt target red lt target blue lt target grech erase Fredr lt erase green gt lt erase blue gt lt x gt lt y gt lt outer diameter gt lt inner diameter gt Note The RGB values for the fixation point drawing color is specified by the lt target _red gt lt target blue gt lt target green gt whereas the color of the fixation c
175. ta Viewer 2002 2008 SR Research Ltd 9 Figure 4 2 Components of the Inspector Window Left Data Tab Right Preference Tab 4 1 1 1 Data Tree Hierarchy When a data file is loaded the tree view panel lists the possible analysis levels in a hierarchical order The user can obtain information on the trial groups and individual trials Within each trial statistics on all events fixations saccades blinks button presses and messages and interest areas can also be retrieved 4 1 1 2 Trial Grouping By clicking on a trial grouping node 3 information on this trial group can be obtained in the bottom panel of the data inspector Typically this includes the label of group values of the grouping variables total number of trials and configurable interest area information see section 6 1 3 on how to perform trial grouping By default trials in a viewing session are grouped by the EyeLink data files loaded The following table lists the group properties if trials are grouped by data file Those fields that are editable in the viewer are marked with an asterisk Right or Binocular Whether the pupil size 1s set by area or diameter Gaze Data type Raw raw pupil center position or pupil minus corneal if running in pupil CR mode as measured by the image processing system Gaze actual gaze position on the display screen fully compensated for head position or HREF the tangent of the rotation angle of the eye relative to the head
176. tandard toolbar EyeLink Data Viewer 2002 2008 SR Research Ltd 109 Once an viewing session is created data files can be loaded by choosing File Import Data gt EyeLink File s from the application menu bar or clicking the button on the standard toolbar In the Load dialog go to the directory of the EDF files that you want to import and select the file s Multiple data files 1 e EDF files can be loaded into one viewing session By default the top panel of the inspector window lists all of the data files R loaded into the current viewing session 1 e the trials in the viewing session were grouped by data file see section 4 1 1 2 on Trial grouping A trial group can be removed from the viewing session by selecting the node clicking the right mouse and choosing the Delete option Important Whether or not to load multiple EDF files into a viewing session depends on the user s choice of analysis outputs Some statistical packages may not be able to handle the analysis output from all the EDF files recorded for one experiment if each EDF file contains lots of trials and a large number of events variables are extracted from the analysis In this case it is advised that the user load one or few EDF files into each viewing session The current tutorial illustrated the case of loading one EDF file to one viewing session e EyeLink Data iewer File Edit Analysis Window Help ojelo ele lt elelaa s
177. templates in the Data Viewer session see section 5 8 8 Automatic Trial Image Interest Area Set EyeLink Data Viewer 2002 2008 SR Research Ltd 131 Association for details The default is false Use Nearest Interest Area for Outlier Fixations If the current fixation is not in any defined interest areas assigns the nearest interest area as the current interest area Fixation Saccade Report Maximum Message Variables for Eye Event Maximum number of messages associated with a given fixation or saccade that will be shown in the output report Eye Event Msg Variable String Match Token If left blank all messages associated with an eye event will be reported otherwise only those messages containing the token will be reported Fixation Map Heat Map Mode If enabled the fixation map will be drawn in colored heat map if unchecked a grayscaled version will be created Sigma in degrees Sets standard deviation of the Gaussian distribution for each fixation point when creating a Fixation map Minimum Contrast Multiplier 0 0 1 0 Sets the contrast between the fixation hotspots and the background 0 with maximum contrast and 1 with minimum contrast Sigma Multiplier for Update Range Number of standard deviations extended for each fixation point when creating the Fixation map For most users keep this setting unchanged Fixation Stream Analysis Fixation Skip Count Defines the number of fixations to skip when lookin
178. ter Figure 6 13 Using Interest Period for Event Filtering Three time periods have been used in a trial output report 1 recording period 2 reaction time period and 3 interest period The recording period START TIME END TIME and DURATION ofa trial starts from the START message in the EDF file and ends on the END message This is fixed for a recording trial regardless how the user set the interest period filters If a valid reaction time definition is found for one trial the RT START TIME is the time of the RT start message e g time of SYNCTIME message RT EVENT END TIME and RT EVENT START TIME are the start and end time of the RT event fixation saccade button or message Reaction time REACTION TIME is calculated as the difference between RT START TIME and RT EVENT START TIME Please note that the RT EVENT END TIME and RT EVENT START TIME will be the same when a button or message is used as the RT end event but will be different when a fixation or saccade is defined as the end event If the user does not create a reaction time definition or no valid reaction time definition is found for one trial REACTION TIME RT EVENT END TIME and RT EVENT START TIME and other variables related to reaction time definition will have missing values whereas RT START TIME will be the same as the trial recording start time START TIME The interest period variables will have different values depending o
179. the current example we recorded the item type 1 e features shared with the search target as the interest area label Since the interest area set file has already been created in the Gen_IAS project see section 8 2 1 we only need to add a command IAREA FILE to inform the Viewer to load the interest areas from the specified file during the viewing session IAREA command is recorded for EyeLink Data Viewer analysis It creates a set of interest areas by reading the segment files Writes segmentation filename path info eyemsg printf V IAREA FILE s seg file name Must be offline to draw to EyeLink screen set offline mode Now we want to create the bitmap for the trial and save the segmentation information To avoid overwriting the file we set the saving option as SV NOREPLACE if create image bitmaps filename_inf seg fn SV_NOREPLACE eyemsg printf ERROR could not create bitmap return SKIP TRIAL Skip the trial 8 3 Data Analysis After the experiment is tested on a few subjects and data are collected EyeLink Data Viewer can be used to perform analysis To illustrate the functionality of the Viewer program the current tutorial examined the data from one subject in detail 8 3 1 Viewing session Manipulation and Data Loading To create a Data Viewing Session DVS click on the EyeLinkDV exe file Once the program starts click File gt New from the menu bar or the button on the s
180. those events and data within the selected interest period custom defined interest period or the default Full Trial Period or Reaction Time Period are exported 6 5 Trial Report EyeLink Data Viewer 2002 2008 SR Research Ltd 53 Trial report summarizes the performance of individual trials Before trying to obtain a trial report make sure that you have completed the reaction time definition and initialized the reaction time events 6 5 1 Obtaining a Trial Report To obtain a trial report Figure 6 12 1 1 2 3 4 5 6 7 From the menus choose Analysis gt Report gt Trial Report Select the variables in the list of available output variables left panel and press gt gt to enter the variables into the list of selected output variables To remove one variable from the output list simply select that variable and press se Lae To change the order in which the variables are listed simply select one variable and use the or button to move it to the desired position Repeat this step until all variables are in the right position Once all the desired variables have been entered into the output list press NEXT button In the Export dialog box browse to the directory in which you want to save the output report In the File name text box type in the name for the document Note if the output report name does not contain an extension 1 e where are any 3
181. tion in which the next saccade is aiming NEXT SAC DURATION Duration of the next saccade in milliseconds NEXT SAC END INTEREST Interest area in which the end point of the next AREAS saccade falls NEXT SAC END TIME Trial time when the next saccade ends NEXT SAC END X X Y coordinates of the end point for the next NEXT SAC END Y saccade NEXT SAC INDEX Ordinal index of the next saccade NEXT SAC IS RT END Whether the next saccade is the end event of the RT definition NEXT SAC LABEL Label of the next saccade NEXT SAC MSG COUNT Number of visible messages associated with the next saccade event This number will not exceed the Maximum Message Variables for Eye Event set in the Output Analysis Preference Settings NEXT SAC MSG TEXT Text string of the messages associated with the next saccade NEXT SAC MSG TIME Trial timel of the message NEXT SAC NEAREST END Nearest interest area to which the end point of the _INTEREST AREA next saccade is assigned EyeLink Data Viewer 2002 2008 SR Research Ltd 62 INTEREST AREA LABEL point of the next saccade is assigned INTEREST AREA next saccade is assigned INTEREST AREA LABEL point of the next saccade is assigned second of the next saccade AREAS saccade falls NEXT SAC START TIME Trial time when the next saccade ends NEXT SAC START X X Y coordinates of the start point for the next NEXT SAC START Y saccade Note Similar analyses are done for the previous sacca
182. to merge the last two fixations on the search target see Figure 8 11 This can be done by selecting the two fixations click on the first fixation press the CTRL key and then click on the second fixation clicking the right mouse button and selecting the Merge operation Once such an operation is performed information on fixations is updated in both the Inspector window and the trial view window g EyeLink Data iewer File Edit Analysis Window Help Relea e e o six Data ai Preferences E i HD_RCN 0 Trial 1 e ED Trial 3 BA Trial 4 EI Trial 5 i O Trial 6 ED Trial 7 H Trial 8 a Fixation 89ms 40 Fixation 273ms 40t Fixation 409ms Label ixation 409ms Start Time 409 ms End Time fi303 ms Duration 4vq x Position 684 9 vg Y Position 215 6 f ai Start EyeLink Data viewer EyeLink Data Viewer E Cut Copy Paste Hide Unhide All Delete Split Drift Correct Select All Select Hidden Trial Grouping Ctrl 6 10j x Woo Eeles Fenm Ctrl X Ctrl C Ctri V gt Delete gt Ctrl D Ctrl A 5 28 PM 2002 2008 SR Research Ltd 119 Figure 8 11 Merging Fixations Drift correcting fixations can also be performed This is only suggested if it is obvious to the user that improper system setup or calibration has resulted in a trial s fixation data containing significant drift that can be easil
183. ts w32_ freeimage bitmap c Loads any of a number of image file formats using the freeimage library creating a device dependent bitmap from it The picture can be loaded to a bitmap matched in size or a full screen bitmap can be created and the image resized to fill it The freermage library www 6ixsoft com This is a freeimage h freeware graphics file library freeimage dll freeimage lib 8 2 3 2 w32_ script main c The w32_script_main c file is modified after w32 _demon_main c An explorer style dialog is used to open the randomization script file for processing To support this the OPENFILENAME structure which contains information that is used to initialize an Open Save dialog box is used After the user closes the dialog information about the user s selection is returned Get the name of the script file i get script filename full screen window szFileName szTitleName Once the script file name is retrieved instead of calling the run_trials function as in the w32_demon_main c file the current experiment calls the run script trials function to run the experiment with trial information read from the script file 8 2 3 3 w32_ script trials c The w32_script_trials c file is modified after the w32_picture_trials c file of the Picture template Essentially this file calls the process script file function to process the script file and extract the useful information for each tri
184. ve been defined in the EDF file see section 7 2 1 on trial variable labels or created during the viewing session see section 6 1 1 on trial variable manager 6 5 3 Using Trial Report Please note that in the above table outputs for all of the variables marked with an change as different interest period filters are used For example the output for a trial filtered by a reaction time period may be different from a full trial output as the former only include a subset of the full trial data in the report Therefore please make sure that you have the right setting for the interest period filter when creating you own reports see figure below see also 6 4 2 In those trials with no reaction time defined missing values will be recorded for those variables marked with a P sign Please also note that event counts only factor in visible events If an event is hidden and not visible it will not contribute to event counts If hidden events are visible then they will apply to event counts 66399 will EyeLink Data Viewer 2002 2008 SR Research Ltd 57 0 x File Edit Analysis Window Help e a Interest Period Settings Pa o Trial View text Trial 4 i og h 160 R30 200 th Buck dd nt fea the newspapers or he would have known that o x lt Data w Preferences eile Trial 1 HE Trial 2 iE trouble was brewing not alone for himslf but for every tidewa
185. viewing session can be reloaded by clicking File gt Open from the menu bar or clicking the gt button on the toolbar and selecting the desired evs file from the open dialog box reopen Look in lm Visualsearch E search res segments EE search evs Open Files of type viewing Session Files Cancel Figure 8 3 Opening a Saved Viewer Viewing session 8 3 2 Trial Manipulation By clicking on the trial nodes R contained within a data file information on participant s performance in individual trials can be examined see section 4 1 1 3 As explained in chapter 4 the trial view window consists of two viewing modes 1 e spatial overlay view and temporal graph view whereas the inspector window provides the list of visible events in the trial middle panel and a summary of the trial performance bottom panel A selected trial can be deleted by clicking the right mouse button and selecting EyeLink Data Viewer 2002 2008 SR Research Ltd 111 the Delete option on the popup menu Once the trial is deleted it is removed from the viewing session and from all of the analysis outputs 8 3 2 1 Loading Trial Bitmap In the current example the V IMGLOAD FILL command loads the specified image to be used as the background for the spatial overlay view of a trial When working with old EyeLink data recordings the user can load a desired trial bitmap by clicking the change the overlay image
186. wide cool veranda that ran around its four sides Figure 4 6 Sample Playback Animation View To save the playback of trial data into a movie file click on the save To Movie button E on the trial view window toolbar In the following Movie Save Options dialog box enter the movie file name file type AVI or MOV frame rate and compression method Click Start to begin moving saving Depending on the size of recording file this may take a long time to finish At any point user can press ESC key to stop the saving process Playing back video clips in the animation view is also supported if the EDF file is created from an SR Research Experiment Builder recording The video clip must be encoded in XVID format and a computer with P4 CPU 1s required for playback in Data Viewer EyeLink Data Viewer 2002 2008 SR Research Ltd 20 5 Working with Events Samples and Interest Areas In addition to providing a file based and a trial based summary of performance the EyeLink Data Viewer allows a detailed examination of event data such as fixations saccades blinks buttons messages as well as raw sample data 5 1 Common Operations The EyeLink Data Viewer allows the user to carry out various manipulations over the events such as selecting a portion of data for further scrutiny excluding or deleting a subset of events from analysis performing drift correction on fixations merging neighboring fixations and saccades etc Select
187. xation that overlaps the start or end of the interest period will be trimmed so that only the portion of fixation within the interest period will be reported Include Display Command Messages Whether display command messages 1 e command message starts with V listed in sections 7 3 2 image loading and 7 3 3 simple graphics should be visible Include Audio Command Messages Whether audio command messages should be visible The following built in audio messages are supported V ARECSTART IV ARECSTOP V VOICEKEY V APLAYSTART and V APLAYSTOP EyeLink Data Viewer 2002 2008 SR Research Ltd 134 9 5 General Trial View Preferences The parameters related to the general trial view preference settings are covered below ai Inspector ED Data wt Preferences Preferences seren General seren Data Loading 3 seen Output Analysis sn Data Filters 2 Data views Sy Overlay Time Plot See Animation Field ication Color accade Color ink Color 4 Color utbon Color essage Color eaction Time Stark eaction Time End Color Selection Square Color Unselected Stroke Wi Selected Stroke width Boo Adjust Saccades with Batch Drifk Correction SO Batch Drift Correct tf Include Fixation in Sin Do Auto Select Fixation in Initial Data View 15T Bs Display RT Graphic Include Graphics Com Fixation Color Saccade Color Blink Col
188. y corrected manually To illustrate the usage of this functionality for any trial select the set of fixations to be adjusted press the Alt key and then use the cursor keys to move the selected fixations to the desired locations see section 5 2 3 Drift Correcting Fixations for more information 8 3 5 Analysis Output In a typical viewing session the final step is to extract useful eye movement information and export the data to statistical software The EyeLink Data Viewer supports the output of several types of analysis reports see chapter 6 Exporting Data The current tutorial focuses mainly on two of them namely the trial output report and the fixation output report 8 3 5 1 Trial output report The trial output report provides a summary of some important measures for individual trials see section 6 5 2 for a complete list of the variables The user may be interested in only a subset of the variables provided by the Viewer For the current example we record trial condition values response time number of fixations as well as information on number of saccades average fixation duration and average saccadic amplitude in a given trial To obtain a trial output report select Analysis Report gt Trial Report from the application menu Select all of the desired variables and enter them to the list of selected output variables see Figure 8 12 Click the Next button and in the Filename edit box enter the desired f
189. y to the Data Viewing session d The trial condition variables and values to use for each trial e The position of the target in a dynamic display EyeLink Data Viewer 2002 2008 SR Research Ltd 4 2 Installation 2 1 System Requirements Operating System Windows 98 NT 2000 or XP Processor PIII 800 MHz or better processor RAM minimum 256 MB RAM 512 MB recommended Disk Space 50 MB free disk space for application plus space required for EyeLink data files and saved viewing sessions Monitor Resolution 1024x768 or better resolution 1600 x 1200 recommended Other Free USB port required 2 2 Setup 1 Install EyeLink Data Viewer by running the installer program EyeLinkDV exe The latest version of the installer program can be downloaded from https www sr support com forums showthread php t 10 2 Install the standalone HASP key driver if this is the first time that the USB dongle have been used on the display PC You may install the driver by clicking Start gt All Programs gt SR Research gt Install HASP Driver from your computer desktop or double clicking on hdd32 exe in C Program Files SR Research Common folder 3 Before starting the application be sure to plug the license key to a USB port of the computer 4 From the computer desktop click Start gt All Programs gt SR Research gt EyeLink gt Data Viewer gt DataViewer to run the application Important A USB Dongle provid

EyeLink Data Viewer User's Manual

Contents

Download Pdf Manuals

Related Search

Related Contents