Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 25, 2016
Last Modified: January 24, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script runs the AntiSaccade Task, a test of inhibitory control, with keyboard input. The implemented procedure is based on Friedman et al (2008).
Friedman, N. P., Miyake, A., Young, S. E., DeFries, J. C., Corley, R. P., & Hewitt, J. K. (2008). Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137, 201-225.
10 minutes
Participants are asked to focus on a fixation cross in the center of the screen. A brief flash is presented on either to the right or the left side of the fixation cross. The brief flash is followed by the target stimulus on the opposite side of the flash. The target is either a left-pointing, a right-pointing, or an up-pointing arrow and it disappears quickly. Participants are asked to press the '?' key on the keyboard if it's a left-pointing arrow, to press the '?' key on the keyboard if it's a right-pointing arrow, and to press the '?' key on the keyboard if it's an up-pointing arrow.
2 (targetLocations: right vs. left) x 3 (targetDirections: right vs. left vs. up) tested within participants (=> 6 different trial types)
- 1 Practice Block: 18* practice trials (change number of trials under section BLOCKS), order of trials randomly determined
Errorfeedback is provided during Practice only
- 1 Test Block: 90 trials, 15 trials per each trial type (change number of trials under section BLOCKS), order of trials randomly determined
Note*: number of trials different from Friedman et al (2008)
Trial-Sequence:
(1) Fixation cross: variable duration, randomly sampled (with replacement) btw. 1,500 and 3,500 ms (in 250ms intervals)
(2) Flash (150ms): a yellow square appears either on the opposite side the target appears on (AntiSaccade)
(3) Target (175ms): target appears
(4) Mask (until response): gray mask covers target
(5) ITI: blank screen for 0ms (editable) before fixation cross returns
- stimulus sizes can be edited under section Editable Parameters
- stimulus left/right positions can be edited under section Editable Parameters
target stimuli are left, right and up pointing arrows
are provided by Millisecond under section Editable Instructions
File Name: antisaccadetask_keyboard_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| propErrorsAS | Error rate for AntiSaccade task |
| meanRTAS | Mean latency (in ms) of correct AntiSaccade responses |
| sdAS | Standard deviation of latencies (in ms) of correct AntiSaccade responses |
File Name: antisaccadetask_keyboard_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialCode | Name of the current trial |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| phase | "practice" vs. "test" |
| fixationDuration | Duration (in ms) of fixationcross |
| targetLocation | Target is located: 'left' vs. 'right' to the fixation cross |
| targetDirection | Target arrow points to: 'left' vs. 'right' vs. 'up' |
| stim | Contains the currently presented arrow image |
| response | The participant's response (scancode of response button) |
| correct | The correctness of the response (1 = correct; 0 = incorrect) |
| latency | The response latency (in ms); measured from onset of target stim |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Ui Parameters |
||
| fontSizeFixation | Sets the height of the fixation cross in canvas % | 15% |
| targetSize | Sets the height of the target images in canvas % | 10% |
| flashSize | Sets the height of the flash stimulus in canvas % | 15% |
| maskSize | Sets the height of the mask stimulus in canvas % | 15% |
Timing Parameters |
||
| flashDuration | Sets the duration (in ms) of the flash | 150 |
| targetDuration | Sets the max. duration of the target presentation in ms | 175 |
| iti | Intertrial interval in ms | 0 |
Coordinates (Proportional) |
||
| leftPos | Coordinate of the left stimulus location in canvas width percentages | 25% |
| rightPos | Coordinate of the right stimulus location in canvas width percentages | 75% |
Response Keys |
||
| leftKey | The scancode of the left responsekey | 203 |
| rightKey | The scancode of the right responsekey | 205 |
| upKey | The scancode of the right responsekey | 200 |