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							APPROACH-AVOIDANCE TASK (AAT) - with Mouse Input

SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 08-17-2012 (original AAT.iqx with joystick input)
last updated:  08-15-2016 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Copyright © 08-15-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script implements the Approach-Avoidance Task (AAT) Paradigm with mouse input as described in:

Wiers, R.W., Rinck, M., Dictus, M. & Wildenberg van den, E. (2009). Relatively strong
automatic appetitive action-tendencies in male carriers OPRM1 G-allele. Genes, Brain and Behavior, 8, 101-106.

This script is based on the original AAT.iqx (with joystick input) published by Millisecond Software LLC


											  *Task*
Participants are asked to do a categorization task of portrait vs. landscape pictures (of 4 different categories, e.g. alcohol, soda etc).
If the picture is a landscape picture, they are asked to move the mouse AWAY from body which shrinks the picture (=AVOID). 
If the picture is a portrait picture, they are asked to move the mouse CLOSER to body which enlarges the picture (=APPROACH). 
Pull (Approach) and Push (Avoid) responses in regard to landscape and portrait formats are counterbalanced across participants by groupnumber.



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

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

build:							Inquisit build
computer.platform:				the platform the script was run on
date, time, subject:			date and time script was run with the current subjectnumber 
/expcondition:					used for counterbalancing experimental conditions
									1: push for landscape, pull for portrait
									2: pull for landscape, push for portrait

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) 
/stimulus:						the presented stimulus image
/targetcategory:				the targetcategory of the targetstimulus, 1 - 4
									1) alcohol pictures
									2) color and shape matched appetitive stimuli (e.g pictures of soda bottles)
									3) positive pictures containing people and animals
									4) negative pictures containing people and animals
/targetformat :					the targetformat of the targetstimulus (l = landscape; p = portrait)
/mouse_y:						helper variable to track the y-position of the cursor
/initialresponse:				stores the original response to the stimulus (PUSH vs. PUL)
/correct:						stores the correctness of the initial response (1 = correct; 0 = error)
/finalresponse:					stores the final response (at time mouse cursor hits top or bottom of screen): PUSH vs. PULL
/changedirection:				stores how often participant changed direction during zooming (0 = no change)
/RT:							stores the latency of the initial response (in ms)
/completeRT:					stores how long it takes until the cursor hits the screen top or bottom (in ms)

(2) Summary data file: 'AATmouseinput_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)
/propcorrect_overall:			proportion correct across all test trials
/meanRT_overall:				mean latency (in ms) of correct responses across all test trials
/SD_RT:							standard deviation of correct responses across all test trials
/medianRT_overall:				median latency (in ms) of correct responses across all test trials

+ corrected AAT Difference Scores for each of the 4 main categories, 
Diff Scores = median latency of correct trials for Push trials - median latency of correct trials for Pull trials
!!! NOTE: latency only for initial response 

/sequence:	  the experimental sequence generated for the participant


EXPERIMENTAL SET-UP
format/direction counterbalanced by group number (odd vs even) (Inquisit Lab: manual input of subject id and group id at beginning of task)
1. runs a trial sequence generation block via helper script AAT_SequenceGenerator.iqx
2. runs a practice block
3. runs the AAT test block

TEST BLOCK:
* 80 test trials (4 categories x 2 formats x 10 repetitions) in a semi randomized order (see below for more info on generating the trial sequence)
* intertrial interval of 300ms

TRIAL SEQUENCE:
Wiers et al (2009) used a semi randomized order of all 80 test stimuli with the following two constraints:
1. no more than three consecutive stimuli of the same category 
2. no more than three consecutive stimuli of the same format 

Note: a helper script "AAT_SequenceGenerator" generates a trialsequence that fulfills those constraints.
1. The time to generate this sequence DOES differ across participants
2. The code is specific to running 8 categories
If more categories should be run, go to section 'BLOCKS' and follow instructions to use a complete randomized algorithm (without constraints).
	
PRACTICE: 
* PracticeStimuli: gray rectangle in landscape and portrait format
* 20 trials (10 landscape and 10 portrait formats in random order)
* gives error feedback

STIMULI
Wiers et al (2009): categorization of 4 types of stimuli 
1) alcohol pictures
2) color and shape matched appetitive stimuli (e.g pictures of soda bottles)
3) good pictures containing people and animals
4) bad pictures containing people and animals

* 10 stimuli per category (each of these in landscape and portrait format)
* The stimuli used in this script are based on the original ones used. 
Millisecond Software thanks Dr. Wiers for generously sharing his material! 

Just a word of caution: the stimuli are culturally specific and may not work for your study. To substitute your own stimuli, go to 
EDITABLE CODE -> editable STIMULI -> item.targets

INSTRUCTIONS
the instructions are not original to Wiers et al (2009). They are provided by Millisecond Software.
They can be edited under section "Editable Instructions"

EDITABLE CODE:
check under EDITABLE CODE 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:

/Startheight_ratioA:			sets the initial size of the landscape pictures (default ratio: 0.5 of active screenheight)
/Startheight_ratioB:			sets the initial size of the portrait pictures (default ratio: 0.6 of active screenheight)
/MinHeight_ratioA:				sets the the min picture height of the landscape pictures(default: 0.05 => 5% of MaxHeight)
/MinHeight_ratioB:				sets the the min picture height of the portrait pictures(default: 0.1 => 10% of MaxHeight)
/intertrialinterval: 			sets the intertrialinterval for the AAT trials (default: 300ms)
/pixeltolerance:				sets the initial tolerance of pixelchanges after participants click
								the center cross (so that accidental movements are not 'punished'; default: 10)

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