The SR Research Experiment Builder SREB is a ocular experiment creative activity tool for usage by Psychologists and Neuroscientists. The SREB is designed to be easy to utilize while keeping a high grade of flexibleness. This alone design combination allows for a broad scope of experimental paradigms to be created by person with small or no scheduling or scripting expertness. When used in combination with the SR Research EyeLinkA® oculus tracking system, the SREB provides seamless integrating into the EyeLink hardware and package platform.
Experiments are created in the Experiment Builder by dragging and dropping experiment constituents into a workspace and configuring the belongingss of the added constituents. There are two chief categories of experiment constituents in the Experiment Builder: Actions and Triggers. Actions tell the computing machine to make something, like exposing a set of artworks on the screen or playing a sound. Gun triggers define the conditions that must be met before an action can be performed. The flow of the experiment is achieved by linking consecutive related constituents in the workspace in a flow diagram like manner.
One of the of import constructs in SR Research Experiment Builder is hierarchal organisation of events in an experiment. A typical experiment can be dissected into several degrees along a hierarchy of Experiment a†’ Blocks a†’ Trials a†’ Trial Runtime / Recording. All of the events within each degree of this hierarchy can be handily wrapped in a cringle ( called sequence or sub-graph in Experiment Builder ) . This allows the whole sequence to be connected to other objects as a unit and be repeated several times in a row.
Making EyeLink Experiments
To make an Experiment with SR Research Experiment Builder, the user needs to take the following the undermentioned stairss:
Building and Test-running Experiment
Participant Data Set Randomization
Following these, a set of files are generated so that the experiment can be run for informations aggregation without trusting on the Experiment Builder application. To exemplify the usage of Experiment Builder, a really simple eye-tracking experiment can be shown which runs three blocks of four tests. In each test, a individual word is displayed in the Centre of the screen.
Making a New Experiment Session
Click on the Experiment Builder to get down a new session. When the application starts:
Click on “ File iˆiˆ? New ” on the application bill of fare saloon.
In the following “ New Project ” duologue box, enter “ Simple ” in the “ Undertaking Name ” edit box.
Click on the button on the right terminal of the “ Project Location ” to shop to the directory where the experiment undertaking should be saved. If you are manually come ining the “ Project Location ” field, delight do certain that the intended directory already exists.
Make sure that “ EyeLink Experiment ” box is checked for an EyeLink experiment.
Note: The user should n’t manually add or take files in the experiment directory.
Configuring Experiment Preference Settings
After a new experiment session is created, the user needs to look into whether the default show and screen penchant scenes are all right for the experiment to be created.
Select “ Edit iˆiˆ? Preferences ” from the application bill of fare saloon or press the “ F4 ” key.
Click on “ Preferences iˆiˆ? Experiment iˆiˆ? Devices iˆiˆ? Display ” to look into show scenes. Make certain that the scenes ( Width, Height, Bits per Pixel, and Refresh Rate ) used are supported by your picture card and proctor.
Click on “ Preferences iˆiˆ? Screen ” to look into Screen Builder scenes. Put the Location Type as “ Center Position ” .
If any of the above scenes have been changed and if you want to maintain the new scenes as defaults for all of your hereafter experiments, chink on the button “ save belongingss as default ” .
Making Experiment Block Sequence
The first measure is to add a block sequence for reiterating blocks:
Click on the Experiment Tab in the Project Explorer Window to get down.
Click on the “ Action ” Check of constituent tool chest.
Choose the “ Sequence ” node, hold down the left mouse button and drag it into the work country.
Topographic point the mouse pointer on top of the “ START ” node ; keep down the left mouse button while traveling the mouse pointer on top of the “ SEQUENCE ” node. This makes the connexion from the “ START ” node to “ SEQUENCE ” node. ( Note: do n’t do a individual or dual chink on the START ” node as this will choose the node alternatively. If you have done so, place the mouse pointer on a clean country in the work infinite and do a individual chink at that place. Remake the current measure once more. )
Click on any clean country in the work window. Snap the right mouse button and choose “ Arrange Layout ” in the popup bill of fare. This will re-arrange the nodes in a hierarchal manner.
Click on the SEQUENCE node in the construction list to go on.
Editing Block Sequence
Next, one will necessitate to redact the belongingss of the Block Sequence. This involves altering the “ Label ” of the sequence to do it more meaningful and altering the “ loop count ” ( entire figure of times a sequence must be executed ) to the existent figure of blocks to be tested.
Click on the value field of the “ Label ” belongings of the Sequence created. Write “ BLOCK ” in the text editor and imperativeness the ENTER key to complete.
Click on the “ Iteration Count ” value field and enter “ 3 ” as the entire figure of sequence cringles.
In the experiment Work Space, dual chink on the Sequence object to go on.
In each block, one has to foremost give an direction, execute a camera apparatus, standardization, and so run the tests ( an illustration has been given below )
Click on the “ Action ” Check of the constituent tool chest, select the “ Display screen ” action, hold down the left mouse button and drag the action into the work country.
Click on the “ Trigger ” Check of the constituent tool chest, select the “ Keyboard ” trigger, hold down the left mouse button and drag the action into the work country.
Add an “ EyeLinkA© Button ” trigger to the work infinite.
Add a “ Timer ” trigger to the work infinite.
Click on the Timer trigger and set the continuance to 20000 milliseconds.
Click on the “ Action ” Check of the constituent tool chest and add a “ Camera Setup ” action to the work infinite. Click on the action and set the “ Background Color ” to white ( 255, 255, 255 ) .
Click on the “ Action ” Check of tool chest and add a “ Sequence ” node to the work infinite. This will be our test sequence.
Topographic point the mouse pointer on top of the “ START ” node. Keep down the left mouse button while traveling the mouse on top of the DISPLAY_SCREEN node. This makes the connexion from the “ start ” node to the “ DISPLAY_SCREEN ” node.
Similarly, connect from “ DISPLAY_SCREEN ” to KEYBOARD, EL_BUTTON, TIMER triggers. Note that a figure is added to these connexions, bespeaking the rating order among the three trigger types.
Make the connexion from the latter three triggers to the “ EL_CAMERA_SETUP ” node and from “ EL_CAMERA_SETUP ” to the SEQUENCE node.
Click at any clean country in the work window. Snap the right mouse button and choose “ Arrange Layout ” in the popup bill of fare. This will re-arrange the nodes in an orderly manner.
Double chink on the “ DISPLAY_SCREEN ” object in the work infinite ( non from the construction list ) until the Screen Builder interfaces displayed in the Graph Editor Window.
Making Instruction Screen
The user may desire to supply direction to the participants at the beginning of the experiment. This can be done by making an image file incorporating the experiment instructions and so utilizing DISPLAY_SCREEN action to demo the image. The direction text can besides be created with the multiline text resource. In the current illustration, multiline text resource text beginning is used.
Click on the multiline text resource button on the screen builder toolbar to choose the type of resource to be added.
Click anyplace on the screen.
In the undermentioned Multiline Text Resource Editor:
Enter the direction text.
Press CTRL + A to choose all text entered.
Click the “ Margins ” button box to put the text borders. Enter 100 ( or desired value ) in all Fieldss. Snap the “ All right ” button on the duologue box.
Make sure that the text is still selected. Now click the buttons on the toolbar to put the coveted text visual aspect ( font name, font size, font manner, alignment manner, line spacing, and text coloring material ) .
Click on the “ Close ” button at the top right corner of the duologue to complete.
To work with images alternatively of texts:
The image resource is flexible plenty to suit assorted manners of exposing ( e.g. , original image size vs. stretched, top-left aligned or centred ) . The undermentioned discusses the option of exposing images in original size or stretching it to a specific dimension.
To expose the image in original size, after the image is added to the show, the user should hold “ Use Original Size ” field of the image checked. Please note that, enabling that field will besides do several properties read-only ( “ Width ” , “ Height ” , “ Niping Location ” , “ Niping Width ” , “ Niping Height ” , and “ Clipping Area is Gaze Contingent ” ) .
To stretch all images to a fixed breadth and tallness ( 1024 A- 768 for illustration ) , after the image is added to the show, the user should foremost do certain that the “ Use Original Size ” field is unbridled. Check the values of “ Width ” and “ Height ” Fieldss of sample image added and adjust them if necessary. In add-on, the user may necessitate to look into the values of “ Clipping Location ” , “ Niping Width ” and “ Clipping Height ” properties, which are used to command the portion of the image to be shown. By default, the cutting breadth and tallness are the same as the image breadth and tallness. Please note that the cutting location is ever top-left based and the location is comparative to the top-left corner of the image.
If images are stretched to different dimensions, the user should add two columns in the experiment informations beginning to stipulate the coveted image breadth and tallness. After the sample image is added to the show, the user should mention the breadth, tallness, cartridge holder breadth, and cartridge holder tallness of the image to the two columns created in the information beginning.
Editing Trial Sequence: Data Source
Next, one will hold to work on the sequence, which will incorporate all necessary triggers and actions in each test. One would besides hold to make a information beginning to be used for puting parametric quantities in single tests.
Click on the last “ SEQUENCE ” node on the construction list to get down.
In the belongings tabular array, chink on the value field of “ LABEL ” . Put it to “ TRIAL ” .
Click on the “ Data Source ” belongings to convey up Data Source Editor.
Click on the “ Add Column ” button. In the undermentioned duologue box, type “ Trial ” ( without citation Markss ) in the Column Name editor box and put Column type as “ Number ” . Click “ OK ” button to complete. Click on the “ Add Column ” button once more. Put the Column Name as “ Word ” and Column type as “ Stringing ” . Click “ OK ” button to complete.
Click on the “ Add Row ” button. Enter the coveted figure ( here 12 ) in the “ Number of Rows ” edit box to bring forth the figure of rows of empty cells ( here 12 ) .
Click on the empty cells of the tabular array merely generated. For this illustration, the values of the “ Trial ” column are set as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. For the “ word ” column, the undermentioned strings have been used: “ One ” , “ Two ” , “ Three ” , “ Four ” , till “ Twelve ” .
Click on the “ Split by ” value field. Enter a value ( here [ 4 ] . This makes certain that merely 4 tests are run in each block. )
Double chink on the “ TRIAL ” sequence node in the construction list. Click on Start node under it to go on.
Editing Trial Sequence: Fixing Sequence and Drift Correction
Each entering test should get down with a prepare sequence action, followed by a impetus rectification action, and so by the existent test recording. The prepare sequence action allows the user to preload the image files or audio cartridge holders for real-time image drawing or sound playing, to pull feedback artworks on the Host Personal computer to measure participants ‘ public presentation, and to reinitialize trigger scenes. The user should typically name this action before executing a impetus rectification.
Click on the “ Action ” Check of the constituent tool chest, select the “ Prepare Sequence ” action, hold down the left mouse button and drag the action into the work infinite.
Click on the added PREPARE SEQUENCE action and reexamine the scenes in the belongings tabular array. Make certain to look into “ Draw To EyeLink Host ” field is set to “ IMAGE ” or “ Crude ” . This will pull image or simple artworks on the host screen for the intent of measuring gaze truth.
Add a “ Drift Correction ” action from the action check of the constituent tool chest.
Click on the “ Action ” Check of tool chest, select the “ Sequence ” node, hold down the left mouse button and drag it into the work infinite.
Make a connexion from the “ START ” node to “ PREPARE_SEQUENCE ” , from “ PREPARE_SEQUENCE ” to “ DRIFT_CORRECTION ” , and from “ DRIFT_CORRECT ” to the “ SEQUENCE ” node.
Click on any clean country in the Work Space. Click the right mouse button and choose “ Arrange Layout ” in the popup bill of fare to re-arrange the nodes in an orderly manner.
Double chink on the freshly created sequence to make full in the existent events in the recording.
Editing Recording Sequence
In a simple recording sequence, one has to expose a screen and so wait for a button imperativeness response from the participant. The test times out automatically if no response is made within a user specified clip interval in seconds. The show screen is so cleared.
Choose the freshly added “ Sequence ” node. Rename the label as “ Recording ” .
Make sure that the “ Record ” and “ Is Real clip ” checkboxes are checked. Double chink on the “ Recording ” node in the construction list until seeing a “ START ” node under it. As we double click on the “ START ” node, the content of the work country window is besides updated.
Click on the “ Action ” Check of the constituent tool chest, select the “ show screen ” action, hold down the left mouse button and drag the action into the work country.
Click on the “ Triggers ” Tab of tool chest, select the “ TIMER ” node, hold down the left mouse button and drag the trigger into the work infinite. Double chink on the Timer object. Enter “ Time out ” ( without quotation mark ) in the “ Message ” value field and 10000 ( clip in MS ) in the “ continuance ” field.
Add an “ EyeLinkA© Button ” trigger.
Add another “ show screen ” action. Double chink on the action and modify its label as “ DISPLAY_BLANK ” . Besides uncheck the “ Send EyeLink DV Message ” box.
Make a connexion from the “ START ” node to “ DISPLAY_SCREEN ” , from “ DISPLAY_SCREEN ” to “ TIMER ” , from “ DISPLAY_SCREEN ” to “ EL_BUTTON ” , from “ TIMER ” to “ DISPLAY_BLANK ” and from “ EL_BUTTON ” to “ DISPLAY_BLANK ” .
Click at any clean country in the work infinite, so snap the right mouse button and choose “ Layout aˆ¦ ” in the popup bill of fare. Click Oklahoma in the undermentioned duologue box. This will re-arrange the nodes in an orderly manner.
Modifying Properties of Display Screen
One must foremost necessitate to look into the belongings scenes of the show screen actions. For better Data Viewer integrating and for reaction clip computation, a message should be written to the EDF file to bespeak the clip when the stimulation was seeable to the participants. In add-on, one may necessitate to pull simple artworks onto the host screen so that the participants ‘ regard truth during entering can be evaluated.
Click on the DISPLAY_SCREEN node. In the belongings window of the action, dual chink on the value field of “ Message ” belongings. Type in “ SYNCTIME ” and so imperativeness ENTER key to register the alteration.
Make sure that the “ Send EyeLinkA© DV Messages ” and “ Use for Host Display ” belongingss are checked.
Choose the “ DISPLAY_BLANK ” action. Double chink on the value field of “ Message ” belongings. Type in “ blank_screen ” and so imperativeness ENTER key to register the alteration.
Make sure that both “ Send EyeLinkA© DV Messages ” and “ Use for Host Display ” checkboxes for the “ DISPLAY_BLANK ” action is unbridled.
Making Display Screen
In here, one has to add a text resource to the show screen and modify the belongingss of the text resource, such as font name, size, text to be displayed, and alignment manner. One besides must hold to make an involvement country for the text. To make this, foremost dual chink on the “ DISPLAY_SCREEN ” object in the work infinite, until the screen builder interface is displayed in the Graph Editor Window.
Click on the “ Insert Text Resource ” button on the Screen Builder tool saloon, and chink at any place in the work country.
Double chink on the current value of Font Name ( “ New Times Roman ” ) . This will convey up a dropdown list. Put the new fount name as “ Arial ” ( or any other ) .
Double chink on the current value of Font Size ( 20 ) . Enter the coveted text size ( 40 ) in the text editor.
Double chink on the far right terminal of the value field of the “ Text ” belongings. This will convey up an property editor duologue.
Click on DataSource node under “ TRIAL ” sequence on the node choice list.
Double chink on the “ word ” node in the node attributes window. This will update the contents of “ Attribute ” editor duologue as “ @ parent.parent.parent.TRIAL_DataSource.Word @ ” .
Click on the “ All right ” button to complete.
Check the “ Use Runtime Word Segment ” box. This will make involvement country automatically for the text used.
Choose the freshly added text resource, chink on both “ Horizontal Center Alignment ” and “ Vertical Center Alignment ” buttons to put the text in the centre of the screen.
Choose the text resource on the work country, click the right mouse button, and choose the “ Lock Selection ” option so that the resource will non be moved by chance.
Writing Trial ID to EDF file
A “ TRIALID ” message should be written to the EDF file so that the existent experiment status under which the test was conducted can be identified during analysis.
Click on the Experiment ( the topmost ) node in the construction list to get down.
In the belongings tabular array, chink on the value field of the “ EyeLinkA© DV Variables ” belongings.
In the undermentioned duologue box, for each of the variables to be added to the test ID message, select the variable and snap the “ ADD ” button. The order of the selected variables can be modified with the “ Move up ” and “ Move down ” buttons.
Click on “ All right ” to complete.
Showing Experiment Progress Message on Tracker Screen
During test recording, a text message can be displayed at the underside of the tracker screen so that the experimenter can be informed of the experiment advancement. For illustration, in this experiment, a text message like “ Trial 1/12 One ” on the tracker screen was shown.
Click on the “ Recording ” sequence node in the construction list to get down.
In the belongings panel, chink on the far right terminal of the value field of the “ EyeLinkA© Record Status Message ” belongings.
In the property editor, enter an equation as:
= ” Trial “ + str ( @ TRIAL_DataSource.Trial @ ) + “ /12 “ +str ( @ TRIAL_DataSource.Word @ )
Click on the “ All right ” button to complete.
Constructing the Experiment
Click on “ Experiment iˆiˆ? Build ” bill of fare to construct the experiment. The Editor Selection Tab in the Graph Editor Window will be set to the “ Output ” check and build information will be displayed. Watch out for mistake ( displayed in ruddy ) and warning ( in brown ) messages during edifice.
The followers is a list of common mistakes during experiment edifice:
Image file non found
No places are added to the usage form
Use of runtime value with pre-build to image option on
No value is set at row… for the column…
The node could non be used in the sequence
Mention to… non found in the graph.
No nexus from node.
Infinite cringle found
No recording sequence found in an EyeLinkA© experiment.
The followers is a list of common warnings during experiment edifice:
The keyboard trigger and mouse trigger is used in a real-time sequence. If this is the instance, look into whether these two triggers are indispensable for the experiment design. If so, uncheck the “ Is Real-time ” box in the recording sequence.
Default value usage in property…
The user may besides prove the experiment by snaping on “ Experiment iˆiˆ? Run ” from the application menu-bar. This will seek to link to the tracker Personal computer and put to death the experiment codification. It should be noted that this should merely be used for the intent of proving and debugging experiment codification. To roll up experiment informations, the user should utilize the deployed version of the experiment as it does non hold to trust on the Experiment Builder application and can be run on a different computing machine.
Deploying the Experiment
After the experiment is built, the user must “ deploy ” the experiment to a new. This will bring forth a set of files so that the experiment can be run on a different computing machine without trusting on the Experiment Builder application. If a information beginning is used, this will make a “ datasets ” subdirectory with a transcript of informations set file in it. The user can make several transcripts of informations set files with the randomizer application
Runing the Experiment
To run the experiment, open the directory where the experiment is deployed to and snap on “ & lt ; file name & gt ; .exe ” . If the EyeLinkA© host application is already running on the Host Personal computer and the Ethernet connexion and scenes between the host and Display Personal computers are all right, the experiment should now get down. This will foremost popup a duologue box inquiring for the informations beginning file. Travel to the “ datasets ” directory and choose the mark informations beginning file. Following this, enter the coveted EDF file name ( must be in DOS 8.3 format ) and chink on the “ All right ” button to go on. Following the initial welcome message, the participant will be shown the camera apparatus and standardization screen and the recording can be started following standardization, proof, and impetus rectification. After the experiment has ended ; an EDF file will be transferred to the Display Personal computer. It may take some clip to finish the file transportation.
Mistake in Initializing Artworks: When you start the experiment and see an “ Error Initializing Graphics ” mistake, delight look into whether the show scenes ( screen declaration, coloring material spots, and refresh rate ) specified for the experiment are supported by your picture card. If non, delight alter the “ Preferences a†’ Experiment a†’ Devices a†’ Display ” scenes.
Mistake in Tracker Version: SR Research Experiment Builder works good with both EyeLink and EyeLink II oculus trackers. The default tracker version is set to EyeLink II ( see “ Preferences a†’ Experiment a†’ Devices a†’ EyeLink ” ) . Therefore, EyeLink I users may see such an mistake message with the default tracker puting. If this is the instance, please set the tracker-version in the device scenes to “ EyeLink I ” .
Participant Data Set Randomization
In most experiments, the user will necessitate to randomise test order so that the experiment stuffs are non presented in the same sequence across participants. Randomization of informations beginning can be done with either an internal randomizer or an external randomizer. These two randomisation methods are about indistinguishable and hence the user may utilize the internal randomizer to execute randomisation unless compensating or Latin-square designs are needed. The constellation of the internal randomisation scenes should be done before deploying the experiment undertaking whereas the external randomisation can be done after deploying the experiment undertaking.
Datas can now be collected from the deployed version of the experiment. Double chink on the feasible file in the deployed experiment directory or type in the.exe file name from the command-line prompt. If the experiment uses a information beginning, a duologue will be displayed, leting the user to take the appropriate informations beginning file. In an EyeLinkA© Experiment, the user will besides be asked to come in the experiment session name. At the End of experiment, an EDF file will be generated for EyeLinkA© entering session and saved in the experiment directory. Optional consequence file ( s ) will be created if the user has specified them in EyeLinkA© and non-EyeLinkA© experiments.
EyeLinkA© entering file can be handily analyzed with EyeLinkA© Data Viewer as the experiments created with Experiment Builder are to the full integrated with this analysis tool. Experiment Builder sends messages to the informations file so that images or simple drawing can be added as sheathing background. The user can besides stipulate test variables, create involvement countries, and send messages for the easiness of informations analysis. The consequence file ( s ) from a non-EyeLinkA© recording session contains columniform end products for selected variables in the experiment. This file can be easy loaded by common statistics bundles.