Last Modified: January 17, 2023 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.
The implemented procedure is based on:
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.
This script uses keyboard input instead of voice recordings.
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
not original; can be easily altered under section EDITABLE INSTRUCTIONS
File Name: alcoholstroopwithkeyboardinput_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 |
| correctPositiveWords | Sum up the correct responses in each category across blocks |
| meanrtAlcoholWords | Mean latency (in ms) of correct responses to Alcohol words across blocks |
| meanrtNegativeWords | Mean latency (in ms) of correct responses to negative words across blocks |
| meanrtNeutralWords | Mean latency (in ms) of correct responses to neutral words across blocks |
| meanrtPositiveWords | Mean latency (in ms) of correct responses to positive words across blocks |
| interferenceAlcohol | Difference btw. mean reaction time to alcohol and neutral words (latencies of correct responses only) => positive: meaning of Alcohol words interfered more than meaning of neutral words on color categorization task |
| interferenceNegativeWords | Difference btw. mean reaction time to negative words and neutral words (latencies of correct responses only) => positive: meaning of Negative words interfered more than meaning of neutral words on color categorization task |
| interferencePositiveWords | Difference btw. mean reaction time to positive words and neutral words (latencies of correct responses only) => positive: meaning of Positive interfered more than meaning of neutral words on color categorization task |
File Name: alcoholstroopwithkeyboardinput_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 |
| 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) scancode/label for the red response button (default: 32 -> d) scancode/label for the green response button (default: 33 -> f) scancode/label for the blue response button (default: 36 -> j) scancode/label for the yellow response button (default: 37 -> 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 |
|---|---|---|
| skipRating | 0 = likert ratings are run (default); 1 = likert ratings are skipped | |
| skiprest | 0 = rest block is run (default) ; 1 = rest block is skipped durations | |
| maxTargetPresentationTime | Maximum time that target words are presented on screen | 1500ms |
| fixationCrossPresentationTime | Time that fixation cross is presented | 500ms |
| posttrialPause | Pause after each stroop trial | 0ms |
| restDuration | Time to rest between stroop blocks responseKeys | 120000ms |
| keyRed | The red response button | "D" |
| keyGreen | The green response button | "F" |
| keyBlue | The blue response button | "J" |
| keyYellow | The yellow response button the four colors used in this script | "K" |
| color1: | red | |
| color2: | green | |
| color3: | blue | |
| color4: | yellow |