___________________________________________________________________________________________________________________ *Food Stroop Task -- Blocked Version* (with keyboard input) ___________________________________________________________________________________________________________________ last updated: 03-01-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 03-01-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a blocked Food Stroop by Millisecond Software. 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 Food Stroop takes advantage of this basic Stroop interference effect by comparing responses to food related words to color and neutral animal words. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants get words of 6 different conditions (e.g. unhealthy and healthy foods, animal names, and color words) in 4 different colors and are asked to press one of 4 keyboard keys as fast as possible. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 5 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'foodstroop_keyboardinput_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. stimword: contains the current stim word stimworditemnumber: stores the itemnumber of the current stimword stimcolor: contains a numeric representation of the current word's display color: 1=red, 2=green, 3=blue, 4=yellow condition: contains a numeric representation of the current condition: 1=congruent color/word 2=incongruent color/word 3=HPF (high calorie food) 4=NTF (low calorie food) 5=HPFA (animal comps for the high calorie food category), 6=NTFA (animal comps for the low calorie food category) response: the participant's key response (scancode of response button) 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) responseCategory: the interpreted key response 1=red, 2=green, 3=blue, 4=yellow correct: the correctness of the response (1 = correct; 0 = incorrect) latency: the response latency (in ms); measured from onset of word (2) Summary data file: 'foodstroop_keyboardinput_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 test trials meanRT: overall mean correct latencies of test trials (in ms) + separate measures for each of the 6 experimental conditions CC=congruent color/word IC=incongruent color/word HPF (high calorie food) NTF (low calorie food) HPFA (animal comps for the high calorie food category), NTFA (animal comps for the low calorie food category) ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 1 Practice Block: 4 trials with "GREEN", "RED", "CAT", "BANANA" 6 Test Blocks: 6 x 12 trials tested in blocked* design by default 1) Congruent Color Words: presents 12 color words (red, blue, green, yellow) in the congruent color (3 repetitions of each color word with constraint that the same color cannot presented consecutively) 2) Incongruent Color Words: presents 12 color words (red, blue, green, yellow) in incongruent colors (3 repetitions of each color word; each time it is presented in a different incongruent color with constraint that the same color cannot presented consecutively) 3) unhealthy food choices: presents 12 unhealthy food choices in 4 colors (colors randomly selected with constraint that the same color cannot presented consecutively ) 4) healthy food choices: presents 12 healthy food choices in 4 colors (colors randomly selected with constraint that the same color cannot presented consecutively ) 5) animals (control for unhealthy food choices): presents 12 animals in 4 colors (colors randomly selected with constraint that the same color cannot presented consecutively) 6) animals (control for healthy food choices): presents 12 animals in 4 colors (colors randomly selected with constraint that the same color cannot presented consecutively) - order of blocks is randomly selected *blocked: the set-up of this script also allows to run the condition in a mixed design (without the constraint of repeated color selections) Trial Sequence: Fixation Cross for 200ms -> Stim word until verbal response (recorded but not evaluated) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ see section Editable Stimuli ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ see section Editable Instructions ___________________________________________________________________________________________________________________ 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: Responsekeys/Labels: /keyred: the red response button (default: 32 -> d) /keygreen: the green response button (default: 33 -> f) /keyblue: the blue response button (default: 36 -> j) /keyyellow: the yellow response button (default: 37 -> k) /getReadyDuration: the duration (in ms) of the get-ready-trial (default: 5000ms)