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*Dots Task*
(keyboard version)
(German instructions)
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 04-02-2018
last updated: 10-10-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 10-10-2023 Millisecond Software
Translation provided by K. Borchert for Millisecond Software
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BACKGROUND INFO
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This script implements the Dots Task. The Dots Task is a spatial incompability task with
arbitrary shape stimuli similar to the Simon Task. The Dots Task was designed to
target working memory and inhibition.
Dots Task Reference:
M.C. Davidson, D. Amso, L.C. Anderson, A. Diamond (2006). Development of cognitive control and
executive functions from 4 to 13 years: Evidence from manipulations of memory, inhibition,
and task switching. Neuropsychologia 44, 2037–2078
Simon Task Reference:
Simon, J.R. and Wolf, J.D. (1963). Choice reaction times as a function of angular stimulus-response
correspondence and age. Ergonomics, 6, 99-105.
Bialystok, E., Craik, F. I. M., Klein, R., & Viswanathan, M. (2004). Bilingualism, Aging,
and Cognitive Control: Evidence From the Simon Task. Psychology and Aging, 19(2), 290-303.
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TASK DESCRIPTION
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Participants are presented trials with either a red circle or a blue circle that appear to the
left or right of a fixation cross.
If participants see a red circle, they are asked to press the corresponding left or right
response key (=congruent trials). For example, if the red circle is left to the fixation cross,
participants are asked to press the left 'A' response key.
If participants see a blue circle, they are asked to press the opposite response key (=incongruent trials).
For example, if the blue circle is left to the fixation cross, participants are asked to
press the right 'L' response key.
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DURATION
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the default set-up of the script takes appr. 2 minutes to complete
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DATA OUTPUT DICTIONARY
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The fields in the data files are:
(1) Raw data file: 'dotstask_mi_raw*.iqdat' (a separate file for each participant)*
build: The specific Inquisit version used (the 'build') that was run
computer.platform: the platform the script was run on (win/mac/ios/android)
date, time: date and time script was run
subject, group: with the current subject/groupnumber
session: with the current session id
blockCode, blockNum: the name and number of the current block (built-in Inquisit variable)
trialCode, trialNum: the name and number of the currently recorded trial (built-in Inquisit variable)
Note: trialNum is a built-in Inquisit variable; it counts all trials run; even those
that do not store data to the data file such as feedback trials. Thus, trialNum
may not reflect the number of main trials run per block.
practice: 1 = practice block;
0 = test
position: 1 = stimulus is positioned on the left;
2 = stimulus is positioned on the right
congruence: 1 = congruent trial;
2 = incongruent trial
prevCongruence: the congruence of the previous trial (important for mixed condition only)
switch: 1 = switch trial (trial type changed from congruent to incongruent or vice versa);
2 = nonswitch trial (trial type stayed the same)
countSwitch: counts the number of switch trials per block
stimulusItem: the presented stimuli in order of trial presentation
response: scancode of the the participant's response key
30 = A = left
38 = L = right
correct: accuracy of response:
1 = correct response;
0 = otherwise
latency: the response latency (in ms); measured from: onset of stim
list.accPractice.mean: the proportion correct during the current practice block
countPractice: counts the number of practice blocks run
(2) Summary data file: 'dotstask_mi_summary*.iqdat' (a separate file for each participant)*
inquisit.version: Inquisit version run
computer.platform: the platform the script was run on (win/mac/ios/android)
startDate: date script was run
startTime: time script was started
subjectId: assigned subject id number
groupId: assigned group id number
sessionId: assigned session id number
elapsedTime: time it took to run script (in ms); measured from onset to offset of script
completed: 0 = script was not completed (prematurely aborted);
1 = script was completed (all conditions run)
///Practice Performance:
countPractice: counts the number of practice blocks run
practiceAcc: the highest proportion correct in one of the practice blocks (if not run, propCorrect = 0)
practicePass: 1 = participant successfully passed the practice session;
0 = otherwise
///Test Performance:
propCorrect: proportion correct across all test trials
meanRT: mean latency of correct responses across all test trials
propCorrectSwitch: proportion correct across switch trials
meanRTSwitch: mean latency of correct responses across switch test trials
switch trial: switch from congruent to incongruent trial and vice versa
propCorrectNonSwitch: proportion correct across nonswitch trials
meanRTNonSwitch: mean latency of correct responses across nonswitch test trials
propCorrectCongruent: proportion correct across congruent test trials
meanRTCongruent: mean latency of correct responses across congruent test trials
propCorrectIncongruent: proportion correct across incongruent test trials
meanRTIncongruent: mean latency of correct responses across incongruent test trials
simonEffect: : ms difference in "[mean corrRT Incongruent] - [mean corrRT Congruent]"
positive value: participants responded faster when
stimulus location and response button location were congruent
("stimulus-response compatibility") => Simon Effect
[negative value: participants responded faster when
stimulus location and response button location
were incongruent]
* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions
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EXPERIMENTAL SET-UP
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1. Practice Block(s): a maximum of 3 (default, can be set under section Editable Parameters) practice blocks of
8 trials. If participants reach a performance of 75% correct (default, can be set under section Editable Parameters)
during any of the blocks, the test block is started - otherwise the script is aborted after 3 unsuccessful
practice blocks. During practice, participants receive positive feedback for 500ms if they
press the correct response button. For incorrect responses as well as noresponses, participants will get a
reminder of the rules and have to retry the trial (at this point, only correct responses are accepted to
move to the next trial).
2. Test: 10 'red circle' trials (5 red circles left, 5 red circles right), 10 'blue circle' trials
(5 blue circle left, 5 blue circle right)
=> random order with constraint that max. 3 of the same trials can be run consecutively
=> number of switch trials will vary (minimum number of switch trials = 6 for 20 trials)
switch trial: switch from congruent to incongruent trial and vice versa
Note: number of trials per block can be set under section Editable Parameters
Trial Sequence:
stimulus (circle)-> max. 1750ms (editable) -> iti: 1000ms (editable)
(timings can easily be changed under section Editable Parameters)
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STIMULI
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provided by Millisecond Software - can be edited under section Editable Stimuli
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INSTRUCTIONS
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provided by Millisecond Software - can be edited under section Editable Instructions
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EDITABLE CODE
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check 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:
/congruentStim: stores the label used for the congruent stim (default: "RED circle")
/incongruentStim: stores the label used for the incongruent stim (default: "BLUE circle")
Note: if the stimuli are changed, picture.congruentStim and picture.incongruentStim need
to be updated accordingly
/minPracticeAcc: the minimum practice performance (proportion correct) to let participants move from a
practice block to a test block (default: 0.75)
/maxPracticeRepeats: number of times a practice blocks can be repeated before the script is aborted (default: 3)
/numberPracticeTrials: the number of practice trials per practice block (default: 8)
/numberTestTrials: the number of test trials per test block (default: 20)
Note: the number of trials should be divisible by 4
/readyDuration: the duration (in ms) of the get-ready-trial
/stimDuration: the duration (in ms) of the stimulus presentation (= response timeout) (default: 1750)
/iti: the intertrial interval (in ms) (default: 1000)
/picSize: the proportional sizing (proportional to canvas height) of the pictures (default: 10%)
/fixationSize: the proportional sizing (proportional to canvas height) of the fixation cross (default: 15%)
/leftX: the left x-coordinate in canvas percentage (default: 30%)
/rightX: the right x-coordinate in canvas percentage (default: 70%)
Note: left edge of canvas = 0%, right edge of canvas = 100%
(canvas = portion of the screen dedicated for the script)
Key Assignment:
/leftKey: the left response button (default: "A")
/rightKey: the the right response button (default: "L")
