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										ALCOHOL DOT PROBE TASK - with images
													-French Version-

SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 05-28-2015
last updated: 08-15-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Copyright © 08-15-2016 Millisecond Software

Millisecond Software thanks Dr. Sylvain Iceta for sharing his translations!


BACKGROUND INFO

											*Purpose*
This script implements the dotprobe procedure with images as used in:

Miller, M.A. & Fillmore, M.T (2010). The effect of image complexity on attentional bias
towards alcohol-related images in adult drinkers. Addiction, 105, 883–890.

Note: Due to the fact that no differences were found with complex stimuli, this script only implements the 
dot probe task with simple pictures.

Millisecond Software thanks Dr. Fillmore for ample assistance and generously sharing the original stimuli!



											  *Task*
After presentation of a fixation cross in the center of the screen, participants are presented with 
2 pictures from two categories (here: alcohol and neutral pictures). The position of the pictures is randomly
chosen to be either left or right to the location of the fixation cross. After a short duration,
the two pictures disappear and a probe stimulus (here: X) appears in the location of one of the
pictures. Participants are asked to press one key if the probe is left and another if the probe is right.



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

(1) Raw data file: 'AlcoholDotProbe_visual_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 subject
/task:												1 = practice; 2 = test	
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) 
/category:											1 = Alcohol ; 2 = Filler 
/congruence:										1 = probe and target (e.g. alcohol) position same; 2 = probe and target (e.g. alcohol) position different
/target_position:									1 = target (e.g. alcohol) image on left; 2 = target (e.g. alcohol) image on right 
/target_x-probe_x:									the x-coordinate (in %) of the target (e.g. alcohol)/ comp ('paired with target') /probe stims
/itemnumber:										itemnumber of currently selected picture
/target_image:										stores the currently presented target (e.g. alcohol) image
/comp_image:										stores the currently presented comp ('paired with target') image
response:											the participant's response (scancode of response button)
latency: 											the response latency in ms (measured from onset of probe)
correct:											accuracy of response (regardless of whether latency >= parameters.minimum_latency)
													1 = correct; 0 = incorrect
/valid:												latency in ms that is >= parameters.minimum_latency
/validcorrect:										1 = response was correct and latency was >= parameters.minimum_latency; 0 = otherwise

(2) Summary data file: 'AlcoholDotProbe_visual_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)

/fixationduration/targetduration:					the duration of the fixation cross (default: 500ms)/the targets (default: 1000ms)/
/probeduration:										the duration of the probe presentation (default: 1000ms)

/iti:												intertrial interval in ms
/probe:												the symbol used for the probe (default: X)
/responsekey_left-responsekey_right:				the keyboard scancodes associated with left probe and right probe
/responsekey_left_label:							responsekey labels
/minimum_latency:									the minimum latency of a correct response that is included into summary variables
													(default: 100ms)


NOTE: all latency/accuracy summary variables are based on correct responses with latencies >= parameters.minimum_latency (default: 100ms)

/propcorrect:										proportion correct overall
/meanrt:											overall mean latency

/propcorrect_congruent_Alcohol:						proportion correct in congruent Alcohol  trials 
/propcorrect_incongruent_Alcohol:					proportion correct in incongruent Alcohol  trials 
/meanRT_congruent_Alcohol:							mean latency of congruent Alcohol  trials
/meanRT_incongruent_Alcohol:						mean latency of incongruent Alcohol  trials
/AB_Alcohol:										Attentional Bias for Alcohol pics : If AB_Alcohol > 0 => faster mean latencies to congruent alcohol trials than incongruent ones

/propcorrect_congruent_Filler:						proportion correct in congruent Filler  trials 
/propcorrect_incongruent_Filler:					proportion correct in incongruent Filler  trials 
/meanRT_congruent_Filler:							mean latency of congruent Filler trials
/meanRT_incongruent_Filler:							mean latency of incongruent Filler trials
/AB_Filler:											Attentional Bias for Filler pics : If AB_Filler > 0 => faster mean latencies to congruent filler trials than incongruent ones (here: should not be different)


EXPERIMENTAL SET-UP
2 categories tested (Alcohol: alcohol; Filler: filler); within-design
- 1 block of 10 practice trials
- 1 block of 80 trials: 40 Alcohol trials (alcohol-neutral pairings) and 40 Filler (filler1-filler2 pairings)
						10 alcohol/neutral simple pictures, all pictures presented 4 times
						=> right/left, followed by prime/not followed by prime => 10 * 4 = 40 trials
						- Filler Trials: same for filler trials
						Note: all 80 trials are randomly sampled without replacement

						DEFAULT TRIAL SEQUENCES
						fixation cross (500ms) -> target image pair (1000ms) -> tp_isi (0ms)-> probe (max. 1000ms)	(latency measured from onset of probe until response or offset of probe; whichever comes first)

STIMULI
Stimuli were generously shared by Dr. Fillmore and can be easily edited under EDITABLE STIMULI

INSTRUCTIONS
Instructions were generously shared by Dr. Fillmore and can be easily edited under EDITABLE CODE -> 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:

/fixationduration/targetduration:				the duration of the fixation cross (default: 500ms)/the targets (default: 1000ms)
/tp_isi:										target-probe interstimulus interval in ms (default: 0ms)
/probeduration:									the duration of the probe presentation (default: 1000ms)
												Note: by default this scripts allows for responses for the entire probe duration;
												the trial terminates after parameters.probeduration is over

/iti:											intertrialpause in ms (default: 0ms)
/probe:											the symbol used for the probe (default: X)
/responsekey_left:								the scancode of the left response button (default: 18)
/responsekey_right:								the scancode of the left response button (default: 23)
/responsekey_left_label:						the label of the left response button ("E")
/responsekey_right_label:						the label of the right response button ("I")
/minimum_latency:								the minimum latency of a correct response that is included into summary variables
												(default: 100ms)

Physical Settings of Display:					Note: change the settings to optimize the display on your computer screen
/target_left_x-target_right_x:					the x-coordinate in % of the right/left target (default: 27%, 73%)
/target_y:										the y-coordinate of the target (default: center at 50%)
/fixationcross_height:							the height of the fixation cross in canvas height percentage (default: 5%)
/probe_height:									the height of the probe in canvas height percentage (default: 5%)
/imageheight:									the height of the image in canvas height percentage (default: 40%)

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