Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 02, 2018
Last Modified: January 12, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
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
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.
2 minutes
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.
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
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)
provided by Millisecond - can be edited under section Editable Stimuli
provided by Millisecond - can be edited
in script "dotstask_keyboard_instructions_inc.iqjs"
File Name: dotstask_mi_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| 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 |
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] |
File Name: dotstask_mi_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| 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 | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| 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 |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| 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 | 3 |
| numberPracticeTrials | The number of practice trials per practice block | 8 |
| numberTestTrials | The number of test trials per test block the number of trials should be divisible by 4 | 20 |
| readyDuration | The duration (in ms) of the get-ready-trial | |
| stimDuration | The duration (in ms) of the stimulus presentation (= response timeout) | 1750 |
| iti | The intertrial interval (in ms) | 1000 |
| picSize | The proportional sizing (proportional to canvas height) of the pictures | 10% |
| fixationSize | The proportional sizing (proportional to canvas height) of the fixation cross | 15% |
| leftX | The left x-coordinate in canvas percentage | 30% |
| rightX | The right x-coordinate in canvas percentage left edge of canvas = 0%, right edge of canvas = 100% (canvas = portion of the screen dedicated for the script) Key Assignment | 70% |
| leftKey | The left response button | "A" |
| rightKey | The the right response button | "L" |