Last Modified: August 05, 2026 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements an Alcohol themed Stroop task. The classic Stroop paradigm demonstrates the interference of word meaning on naming the color in which the words are written as measured by reaction time/accuracy differences to color-meaning congruent and color-meaning incongruent combinations. The Alcohol Stroop takes advantage of this basic Stroop interference effect by comparing reaction times to alcohol related words and neutral words (baseline): it is expected that word categories that grab a participant's attention significantly interfere with processing the color of the word and slow down response times.
The implemented procedure is based on Bauer & Cox (1998). This script uses keyboard input instead of voice recordings.
Bauer, D. & Cox, W.M. (1998). Alcohol-relatedwords are distracting to both alcohol abusers and non-abusers in the Stroop colournaming task. Addiction, 93, 1539–42.
12 minutes
Participants are presented words from 4 different categories (alcohol, neutral, positive, negative) in four different colors (blue, red, yellow, green) and are asked to press one of four response keys to indicate the color of the words regardless of their meaning. At the end, participants are asked to rate how emotionally intense they would rate the words (optional task).
4 categories (alcohol words, positive words, negative words, neutral words) tested within subjects
1. Practice Block: 24 trials (this script uses the words "one" to "ten" as practice stimuli)
2. 2 x Test Block: 2x160 trials (= 4 categories x 10 stimuli per category x 4 repetitions);
• order is randomly determined
• colors are randomly sampled for each word (Constraint: all colors appear equally often for each category)
repeat words can repeat colors)
• fixation cross is presented for 500ms (default) -> target words are presented for a maximum of 1500ms (=response window)
• error feedback given; to remove follow instructions under TRIALS
3. In between the two Testblocks: 2min Rest period (optional, go to Editable Parameters-> Editable Values)
4. Ratings (optional, go to Editable Parameters -> Editable Values)
• original stimuli by Bauer & Cox (1998), can be edited under section EDITABLE STIMULI
in script 'alcoholstroop_keyboard_stimuli_inc.iqjs'
not original; can be easily altered under section EDITABLE INSTRUCTIONS
in script 'alcoholstroop_keyboard_instruct_inc.iqjs'
File Name: alcoholstroop_keyboard_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 |
| elapsedTime | Session duration in ms |
| 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 |
| completed | 0 = Test was not completed 1 = Test was completed |
Summary Performance Metrics: Test Trials Only |
|
| errorRate | Overall error rate (across all test trials) |
| meanCorrRT | Mean correct response time (in ms) |
| errorRateAlcohol | Error rate in alcohol trials |
| errorRatePositive | Error rate in positive trials |
| errorRateNegative | Error rate in negative trials |
| errorRateNeutral | Error rate in neutral trials (baseline) |
| meanCorrRTAlcohol | Mean correct response time (in ms) in alcohol trials |
| meanCorrRTPositive | Mean correct response time (in ms) in positive trials |
| meanCorrRTNegative | Mean correct response time (in ms) in negative trials |
| meanCorrRTNeutral | Mean correct response time (in ms) in neutral trials (baseline) |
Speed-Accuracy Trade Off: Linear Integrated Speed-Accuracy Score, Lisas ("Error-Corrected Processing Speed") |
|
| 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 |
| lisasAlcohol | LISAS score for alcohol trials |
| lisasPositive | LISAS score for positive trials |
| lisasNegative | LISAS score for negative trials |
| lisasNeutral | LISAS score for neutral trials (baseline) |
Stroop (Interference) Effects |
|
| stroopAlcoholError | Difference in error rates (Alcohol-Neutral) => positive difference: participants were less accurate categorizing alcohol stims than neutral ones |
| stroopPositiveError | Difference in error rates (Positive-Neutral) => positive difference: participants were less accurate categorizing positive stims than neutral ones |
| stroopNegativeError | Difference in error rates (Negative-Neutral) => positive difference: participants were less accurate categorizing negative stims than neutral ones |
| stroopAlcoholRT | Difference in meanCorrRT for (Alcohol - Neutral) => positive difference: participants were on average faster correctly categorizing neutral stims than alcohol ones |
| stroopPositiveRT | Difference in meanCorrRT for (Positive - Neutral) => positive difference: participants were on average faster correctly categorizing neutral stims than positive ones |
| stroopNegativeRT | Difference in meanCorrRT for (Alcohol - Neutral) => positive difference: participants were on average faster correctly categorizing neutral stims than negative ones |
| stroopLisasAlcohol | Difference in LISAS scores ("error-corrected processing speed") from Alcohol and Neutral Trials => positive difference, "error-corrected processing speed" was faster for neutral than for alcohol ones => a positive difference supports that processing alcohol trials required more cognitive effort, time, or accuracy sacrifices than processing neutral trials |
| stroopLisasPositive | Difference in LISAS scores ("error-corrected processing speed") from Positive and Neutral Trials => positive difference, "error-corrected processing speed" was faster for neutral than for positive ones => a positive difference supports that processing positive trials required more cognitive effort, time, or accuracy sacrifices than processing neutral trials |
| stroopLisasNegative | Difference in LISAS scores ("error-corrected processing speed") from Negative and Neutral Trials => positive difference, "error-corrected processing speed" was faster for neutral than for negative ones => a positive difference supports that processing negative trials required more cognitive effort, time, or accuracy sacrifices than processing neutral trials |
File Name: alcoholstroop_keyboard_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. |
| target | The currently selected target word |
| color | The currently selected color |
| stimulusItem | Stimulusitem in the order presented |
| response | The participant's response (scancode of responsekey) |
| responseText | Label of pressed response key red response button (default: d) green response button (default: f) blue response button (default: j) yellow response button (default: k) |
| correct | The correctness of the response (1 = correct; 0 = incorrect) |
| latency | The response latency (in ms); measured from onset of word correct_Alcoholwords - |
| correctPositiveWords | Sum up the correct responses in each category across blocks |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Design |
||
| skipRating | 0 = likert ratings are run; 1 = likert ratings are skipped | 0 |
| skiprest | 0 = rest block is run ; 1 = rest block is skipped | 0 |
Timing Parameters |
||
| maxTargetPresentationTime | Maximum time that target words are presented on screen in ms | 1500 |
| fixationCrossPresentationTime | Time that fixation cross is presented in ms | 500 |
| posttrialPause | Pause after each stroop trial in ms | 0 |
| restDuration | Time to rest between stroop blocks in ms | 120000 |
Responsekeys |
||
| keyRed | The red response button | "D" |
| keyGreen | The green response button | "F" |
| keyBlue | The blue response button | "J" |
| keyYellow | The yellow response button | "K" |
The Four Colors Used In This Script |
||
| color1 | red | |
| color2 | green | |
| color3 | blue | |
| color4 | yellow | |