Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: April 02, 2018
Last Modified: August 06, 2026 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Dots Task (Davidson et al, 2006), a spatial incompability task with arbitrary shape stimuli similar to the Simon Task. The Dots Task was designed to target working memory and inhibition.
This script uses keyboard responses.
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.
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 |
|---|---|
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| 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 |
| 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 |
Speed-Accuracy Trade Off: Linear Integrated Speed-Accuracy Score, Lisas ("Error-Corrected Processing Speed" In Ms) |
|
| sdRTPooled | The pooled standard deviation of correct response times across all test trials |
| errorSDPooled | The pooled standard deviation of error rates across all test trials |
| lisasCongruent | LISAS score for Congruent trials |
| lisasIncongruent | LISAS score for Incongruent trials |
Simon Bias Scores Based On: Accuracy, Response Times, And Lisas |
|
| simonEffectAcc | Difference in proportions correct "[congruent] - [incongruent]" positive value: participants made more errors on incongruent than on congruent trials |
| simonEffectRT | Ms difference in "[mean corrRT Incongruent] - [mean corrRT Congruent]" positive value: participants responded faster on congruent than on incongruent trials |
| simonEffectLisas | Difference in LISAS scores ("error-corrected processing speed") from Incongruent and Congruent Trials (lisasIncongruent - lisasCongruent) => integration of response time and accuracy in one measure => positive difference, "error-corrected processing speed" was faster for Congruent than for Incongruent ones => a positive difference supports that processing Incongruent trials required more cognitive effort, time, or accuracy sacrifices than processing congruent trials |
File Name: dotstask_mi_raw*.iqdat
| Name | Description |
|---|---|
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| 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 |
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| 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. |
| 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 |
| responseText | Label of response key |
| 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 |
|---|---|---|
Design |
||
| minPracticeAcc | The minimum practice performance (proportion correct) to let participants move from a practice block to a test block | 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 |
Sizing Parameters |
||
| 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) | 70% |
Timing Parameters |
||
| readyDuration | The duration (in ms) of the get-ready-trial | 2000 |
| stimDuration | The duration (in ms) of the stimulus presentation (= response timeout) | 1750 |
| iti | The intertrial interval (in ms) | 1000 |
Response Keys |
||
| leftKey | Left response key (left on QWERTY keyboard) | "A" |
| rightKey | Right response key (right on QWERTY keyboard) | "L" |