Chinese Version ___________________________________________________________________________________________________________________ *STROOP TASK - with keyboard input* ___________________________________________________________________________________________________________________ last updated: 04-22-2025 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 04-22-2025 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a version of the classic Stroop Task with keyboard input. The classic Stroop paradigm demonstrates the interference of word meaning on the naming of the color in which the words are written as measured by reaction time/accuracy differences to color-meaning congruent and color-meaning incongruent combinations. Reference: Stroop, J, R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18, 643-662. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are given color words written in color and are asked to indicate the color of the word (not its meaning) by key press as fast as they can without making too many errors. Congruent trials: color word and the color it is presented in are the same Incongruent trials: color word and the color it is presented in are not the same Control trials: colored rectangles ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 2 minutes to complete ___________________________________________________________________________________________________________________ DATA OUTPUT DICTIONARY ___________________________________________________________________________________________________________________ The fields in the data files are: (1) Raw data file: 'stroopwithcontrolkeyboard_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. congruency: 1 = congruent (color of word and meaning of word are the same); 2 = incongruent (color of word and meaning of word are different); 3 = control (rectangles) stimulusItem: the presented words response: the participant's response (scancode of response button) 32 = D (red) 33 = F (green) 36 = J (blue) 37 = K (black) responseCategory: the interpreted key response: "red" "green" "blue" "green" correct: the correctness of the response (1 = correct; 0 = incorrect) latency: the response latency (in ms); measured from onset of word congruentCorrect: number of correct congruent responses incongruentCorrect: number of correct incongruent responses (2) Summary data file: 'stroopwithcontrolkeyboard_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) propCorrect: overall proportion correct of all trials meanRT: overall mean latency (in ms) of all correct trials propCorrectCongruent: proportion correct of congruent trials propCorrectIncongruent: proportion correct of all incongruent trials propCorrectControl: proportion correct of all control trials meanRTCorrCongruent: mean latency of all correct congruent trials (in ms) meanRTCorrIncongruent: mean latency of all correct incongruent trials (in ms) meanRTCorrControl: mean latency of all correct control trials (in ms) //Stroop Effects stroopAccuracy: Difference in proportion corrects for (Congruent-Incongruent) => positive difference: participants were more accurate on categorizing congruent stims than on incongruent ones stroopLatency: Difference in meanCorrRT for (Incongruent - Congruent) => positive difference: participants were on average faster on correctly categorizing congruent stims than on incongruent ones stroopInhibitionAccuracy: Difference in proportion corrects for (Control - Incongruent) => positive difference: participants were more accurate on categorizing control stims than on incongruent ones (this performance difference ~ cost of inhibiting the dominant response) stroopInhibitionLatency: Difference in meanCorrRT for (Incongruent - Control) => positive Difference: participants were on average faster on correctly categorizing control stims than on incongruent ones (this latency difference ~ cost of inhibiting the dominant response) ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 1 Testblock with: * 4 colors (red, green, blue, black) x 3 color-stim congruency (congruent, incongruent, control) x 7 repetitions = 84 trials * trials are randomly sampled Trial Timing: - stimuli stay on screen until response (latencies are measured from onset of stimuli) - intertrial interval of 200ms - error feedback of 400ms ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ congruent/incongruent: color words control: rectangle shapes see "stroopwithcontrolkeyboard_instructions_inc.iqjs" ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are not original to the task. They are provided by Millisecond Software. See "stroopwithcontrolkeyboard_instructions_inc.iqjs" ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ 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: /keyRed: the red response button (default: 32 -> d) /keyGreen: the green response button (default: 33 -> f) /keyBlue: the blue response button (default: 36 -> j) /keyBlack: the black response button (default: 37 -> k)