Return to the AntiSaccade Task (Keyboard) page
Script Author: Katja Borchert, Ph.D. (firstname.lastname@example.org) for Millisecond Software, LLC
last updated: 02-14-2018 by K. Borchert (email@example.com) for Millisecond Software, LLC
Script Copyright © 02-14-2018 Millisecond Software
This script runs the AntiSaccade Task with keyboard input described in:
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.
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.
Task takes ~10minutes.
DATA FILE INFORMATION:
The default data stored in the data files are:
(1) Raw data file: 'antisaccadetask_keyboard_raw*.iqdat' (a separate file for each participant)
build: Inquisit build
computer.platform: the platform the script was run on
date, time, subject, group: date and time script was run with the current subject/groupnumber
blockcode, blocknum: the name and number of the current block
trialcode, trialnum: the name and number of the currently recorded trial
(Note: not all trials that are run might record data)
/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 target
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
(2) Summary data file: 'antisaccadetask_keyboard_summary*.iqdat' (a separate file for each participant)
script.startdate: date script was run
script.starttime: time script was started
script.subjectid: subject id number
script.groupid: group id number
script.elapsedtime: time it took to run script (in ms)
computer.platform: the platform the script was run on
/completed: 0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
/properrors_AS: error rate for AntiSaccade task
/meanRT_AS: mean latency (in ms) of correct AntiSaccade responses
/SD_AS: standard deviation of latencies of correct AntiSaccade responses
* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions
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
- 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)
(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 Software under section Editable Instructions
check under EDITABLE CODE below for (relatively) easily editable parameters, stimuli, instructions etc.
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code to further customize your experiment.
The parameters you can change are:
User Interface (UI) parameters:
/fontsize_fixation: sets the height of the fixation cross in canvas % (default: 15%)
/ targetsize: sets the height of the targets in canvas % (default: 5%)
/ flashSize: sets the height of the flash stimulus in canvas % (default: 15%)
/ maskSize: sets the height of the mask stimulus in canvas % (default: 15%)
/stimduration: sets the max. duration of the target presentation in ms (default: 2500ms)
/iti: intertrial interval in ms (default: 500ms)
/leftPos: coordinate of the left stimulus location in canvas width percentages (default: 25% -> center is 50%)
/rightPos: coordinate of the right stimulus location in canvas width percentages (default: 75% -> center is 50%)
/leftKey: the scancode of the left responsekey (default: 203)
/leftKey_label: the corresponding left responsekey label (default: "←")
/rightKey: the scancode of the right responsekey (default: 205)
/rightKey_label: the corresponding right responsekey label (default: "→")
/upKey: the scancode of the right responsekey (default: 200)
/upKey_label: the corresponding right responsekey label (default: "↑")