Return to the Alcohol Stroop Task - Keyboard page
						
									   ALCOHOL STROOP TASK - with keyboard input
SCRIPT INFO

last updated: 02-04-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC
Copyright © 02-04-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script implements an Alcohol themed Stroop task as used by:

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.

											  *Task*
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).


DATA FILE INFORMATION: 
The default data stored in the data files are:

(1) Raw data file: 'AlcoholStroopWithKeyboardInput_raw*.iqdat' (a separate file for each participant)

build:							Inquisit build
computer.platform:				the platform the script was run on
date, time, subject, group:		date and time script was run with the current subject/groupnumber 
blockcode, blocknum:			the name and number of the current block
trialcode, trialnum: 			the name and number of the currently recorded trial
									(Note: not all trials that are run might record data; by default data is collected unless /recorddata = false is set for a particular trial/block) 
values.target:					the currently selected target word
values.color:					the currently selected color
stimulusitem:					stimulusitem in the order presented
response:						the participant's response (scancode of responsekey)
correct:						the correctness of the response (1 = correct; 0 = incorrect)
latency: 						the response latency (in ms)
/correct_Alcoholwords - 
/correct_positivewords:			sum up the correct responses in each category across blocks	

(2) Summary data file: 'AlcoholStroopWithKeyboardInput_summary*.iqdat' (a separate file for each participant)

script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				subject id number
script.groupid:					group id number
script.elapsedtime:				time it took to run script (in ms)
computer.platform:				the platform the script was run on
/completed:						0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
/correct_Alcoholwords - 
/correct_positivewords:			sum up the correct responses in each category across blocks	
/meanRT_Alcoholwords:			mean latency of correct responses to Alcohol words across blocks
/meanRT_negativewords:			mean latency of correct responses to negative words across blocks
/meanRT_neutralwords:			mean latency of correct responses to neutral words across blocks
/meanRT_positivewords:			mean latency of correct responses to positive words across blocks
/Interference_alcohol:  		Difference btw. mean reaction time to alcohol and neutral words (latencies of correct responses only)
/Interference_negativewords: 	Difference btw. mean reaction time to negative words and neutral words (latencies of correct responses only)
/Interference_positivewords:	Difference btw. mean reaction time to positive words and neutral words (latencies of correct responses only)

EXPERIMENTAL SET-UP
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)
	Note: repeat words can repeat colors)
	* fixation cross is presented for 500ms (default) -> target words are presented for a maximum of 1500ms
	* 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)

STIMULI
* original stimuli by Bauer & Cox (1998)

INSTRUCTIONS
not original; can be easily altered under 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:

/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 (default: 1500ms)
/fixationcrosspresentationtime:				time that fixation cross is presented (default: 500ms)
/posttrialpause:							pause after each stroop trial (default: 0ms)
/restduration:								time to rest between stroop blocks (default: 120000ms)

Responsekeys/Labels:
/keyred/redlabel:							scancode/label for the red response button (default: 32 -> d)
/keygreen/greenlabel:						scancode/label for the green response button (default: 33 -> f)
/keyblue/bluelabel:							scancode/label for the blue response button (default: 36 -> j)
/keyyellow/yellowlabel:						scancode/label for the yellow response button (default: 37 -> k)

the four colors used in this script:
/color1 = red
/color2 = green
/color3 = blue
/color4 = yellow

Copyright © Millisecond Software. All rights reserved.
Contact | Terms of Service | Security Statement | Employment