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Template: Countermanding Paradigm
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Joined: Sep 2020
Posts: 20

#1
10-05-2020, 01:26 PM
Countermanding Paradigm

Required Experiment Builder Version: 2.3.38 or higher
EyeLink Required: Yes
Type: Complete Example
Difficulty Level: Moderate

This example illustrates:
  • Implementation of a fixed Inter-Trial Interval.
  • Implementation of a performance based up / down or staircase method to adjust difficult of the task.
  • Use of basic conditional checks for different trial types and perform a drift check every 8th trial.

Description:
This example is based on the consensus guide for countermanding paradigm:
  • Verruggen, F., et al. (2019). A consensus guide to capturing the ability to inhibit actions and impulsive behaviors in the stop-signal task. eLife. 8, e46323.
Each trial start with a central fixation stimulus, and after the participant maintains gaze for a randomized period between 500 and 1000 msec a peripheral stimulus will appear either to the left or right side of the fixation stimulus. Concurrently, the central fixation stimulus will disappear. On 75% of the trials (GO trials), the participant has to saccade as quickly as possible to the peripheral stimulus. If the participant does not look within 1500 msecs an error message will appear to remind the participant to speed up response. On the reminding 25% of the trials (STOP trials), the central fixation stimulus will reappear after a stop-signal delay (SSD). This SSD is adaptive based on the performance of the participant and is initially set at 9 frames (Adaptive_SSD_frames, 150 msec for a 60 Hz refresh rate experiment). The performance of the previous trial is saved in the Previous_trial_perf variable. If the participant successfully inhibits a saccade to the stimulus, the SSD is increased by 1 frame, while if the participant failed the previous trial the SSD is decreased by 1 frame.

**Additional detailed information about the project is given in the notes section for most nodes. To see notes for a given node, either mouse over that node or click on it to display the notes window. If the notes window is not visible, go to the "View" drop down menu in Experiment Builder, select "Properties", and check "Note".

Instructions:
  1. Download the Habituation.ebz example.
  2. Launch the Experiment Builder application.
  3. Unpack the Habituation.ebz file to a location on your Experiment Builder PC with "File menu -> Unpack".
  4. Open the project in Experiment Builder.
  5. Deploy the project to a new folder.
  6. Run the Habituation.exe from the deployed directory.

.ebz   Countermanding_Task.ebz (Size: 65.54 KB / Downloads: 13)