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									Emotion Word Dot Probe Task
									-Attentional Bias Task-
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 09-27-2017
last updated:  03-09-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-09-2020 Millisecond Software

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BACKGROUND INFO 	
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This script implements an emotion dotprobe procedure to measure attentional bias towards emotion words from 
different categories.

The implemented procedure is based on:

Tina M. Sutton & Jeanette Altarriba (2011). The automatic activation and perception of emotion
in word processing: Evidence from a modified dot probe paradigm.
Journal of Cognitive Psychology, 23:6, 736-747,
DOI: 10.1080/20445911.2011.554392

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TASK DESCRIPTION	
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Participants are presented word pairs consisting of one emotion word and one control word
flashed onto the screen to the left (top) or right (bottom) of a center fixation cross for a short duration.
The word pairs are immediately followed by the letter 'R' or 'P'(= the probe). The probe is presented either
in the location of the emotion word or in the location of the control word.
Participants are asked to press one key (R) when the probe is an R and another key (P)
if the probe is a P.

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DURATION 
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the default set-up of the script takes appr. 2 minutes to complete

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

(1) Raw data file: 'emotiondotprobe_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
script.sessionid:					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. 								
									
parameters.horizontalPresentation:	true (1) = the words will be presented left and right next to the fixation cross (default)
									false (0) = the words will be presented on top and bottom of the fixation cross => vertical presentation

parameters.conditionOrder:			the order in which the emotion blocks are run:			
									"negative -> positive" (odd groupnumbers); "positive -> negative" (odd groupnumbers)
	
	
valence:							"negative" vs. "positive"
CTRL:								stores the current control word (CTRL)
CTRL_x:								the assigned x-coordinate for control words
CTRL_y:								the assigned y-coordinate for control words
EW:									stores the current emotion word (EW)
EWlocation:							1 = left (top); 2 = right (bottom)
EW_x:								the assigned x-coordinate for EW words
EW_y:								the assigned y-coordinate for EW words
probe:								stores the current probe letter
probeLocation:						1 = left (top); 2 = right (bottom)		
probe_x:							the assigned x-coordinate for the probe letter
probe_y:							the assigned y-coordinate for the probe letter
congruence:							1 = probe sits in EW position; 0 = probe sits in CTRL position		
				
response:							the participant's response (scancode of response button)
										19 = R
										25 = P
										
correct:							accuracy of response: 1 = correct response; 0 = otherwise
latency: 							the response latency (in ms); measured from: onset of probe


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

computer.platform:					the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:						assigned group id number
script.sessionid:					assigned session id number
script.elapsedtime:					time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
									1 = script was completed (all conditions run)

Task Parameters:
parameters.horizontalPresentation:	true (1) = the words will be presented left and right next to the fixation cross (default)
									false (0) = the words will be presented on top and bottom of the fixation cross => vertical presentation

parameters.conditionOrder:			the order in which the emotion blocks are run:			
									"negative -> positive" (odd groupnumbers); "positive -> negative" (odd groupnumbers)

Summary Variables:	
								
propCorrect_negEW_congruent:		proportion correct responses for negative words when the probe was presented in  Position
propCorrect_negEW_incongruent:		proportion correct responses for negative words when the probe was presented in CTRL Position
propCorrect_posEW_congruent:		proportion correct responses for positive words when the probe was presented in  Position
propCorrect_posEW_incongruent:		proportion correct responses for positive words when the probe was presented in CTRL Position

meanRT_negEW_congruent:				mean latency (in ms) of correct responses for negative words when the probe was presented in  Position
meanRT_negEW_incongruent:			mean latency (in ms) of correct responses for negative words when the probe was presented in CTRL Position

AB_Negative:						AB = Attentional Bias Measure
										positive value = (Attentional) Focus towards Negative Words
										negative value = Avoidance of Negative Words
									
meanRT_posEW_congruent:				mean latency (in ms) of correct responses for positive words when the probe was presented in  Position
meanRT_posEW_incongruent:			mean latency (in ms) of correct responses for positive words when the probe was presented in CTRL Position

AB_Positive:						AB = Attentional Bias Measure
										positive value = Focus (Attentional Bias) towards Positive Words
										negative value = Avoidance of Positive Words			
								
* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions

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EXPERIMENTAL SET-UP 
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2 emotions x 2 probe congruences are tested in a mixed design (emotions are blocked)
The order of the 'positive' and 'negative' blocks is counterbalanced by groupnumber.
Odd groupnumbers run order "Negative -> Positive"
Even groupnumbers run order "Positive -> Negative"

Practice Block:
* Each test block is preceded by a practice block that presents 6 practice trials to adjust to the task.
* In this script practice trials will turn into test trials without further interruption.
* word pairs are fixed but presented in random order
* locations of words is selected randomly with replacement
* location of probe is selected randomly with replacement
* 50% of the probes during practice trials are randomly selected to be probe1 (R)

Test Block:
* 14 trials
* word pairs are fixed but presented in random order
* 50% of the probes in each test block are randomly selected to be probe1 (R)
* 50% of the test trials in each block present congruent probes (sit in place of emotion words)

across both test blocks (see Sutton & Altarriba, 2011, p.741):
* the emotion word (EW) is located on the left(above) half the time (and half of the left EW are followed by a probe)
Note: this script balances congruence x EWlocation across the two test blocks (due to the number of trials it's not
possible to achieve balance within one test block). If the number of trials per block is changed to 16 (for example),
complete balancing across 1 block would be possible.

Trial Sequence:
Fixation (default: 500ms) -> Word Pair (default: 180ms) -> Mask (optional, default: 0ms)-> Probe (until response)->errorfeedback for 500ms (if incorrect response))
Note: if no response occurrs within 2000ms, a response reminder is flashed onto the screen.


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STIMULI
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emotion and control words for the test blocks are taken from Sutton & Altarriba (2011).
Negative words were paired with words from category "sports equipment" in a pseudo-random way,
while trying to match the wordlength of each pair.
Positive words were paired with words from category "animals" in a pseudo-random way,
while trying to match the wordlength of each pair.
Practice words were added by Millisecond Software
(negative words paired with fruits, positive words paired with furniture).
All words can be changed under section Editable Stimuli.

Words are presented white on a black background with font Arial.
To change sizing in screen locations, check section Editable Parameters.

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INSTRUCTIONS 
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provided by Millisecond Software - can be edited under section Editable Instructions

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EDITABLE CODE 
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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:

/runMask:						true (1) = the script will mask ("XXXXX") the emotion and control words
								false (0) = the script will not mask the emotion and control words (default)
							
/horizontalPresentation:		true (1) = the words will be presented left and right next to the fixation cross (default)
								false (0) = the words will be presented on top and bottom of the fixation cross => vertical presentation

/fixationDuration:				the duration (in ms) of the fixation cross at the start of trial (default: 500ms)
/wordPresentationDuration:		the duration (in ms) of the word presentations (default: 180ms)

/maskDuration:					the duration (in ms) of the mask (if runMask = true) (default: 0)
								Note: Sutton & Altarriba (2011, Experiment1): word presentation for 30ms and mask for 150ms
								
/iti:							the intertrial interval (in ms) (default: 0ms)
/readyDuration:					duration (in ms) of the 'get ready' trial (default: 5000ms)
/reminderOnset:					onset (in ms) of reminder after probe has appeared on screen (default: 2000ms after onset of probe)

/probe1_responsekey:			the response key for probe 1 (default: "R", left response key)
/probe1:						probe 1 (default: R)
/probe2_responsekey:			the response key for probe 2 (default: "P", right response key)
/probe2:						probe 2 (default: P)

Interface:

Note: Sutton & Altarriba (2011, p. 741):
"The more central edge of each word appeared at 1.5degree and the distal edge at a maximum of 5degree of visual angle from
fixation."
Due to different monitor sizing, final positioning of the words is left open and can be easily changed by
changing the coordinate values below.

/fixationSize:					the proportional size of the fixation cross to canvas height (default: 8%)
/wordSize:						the proportional size of the words to canvas height (default: 8%)					
/left_x:						the left coordinate  of the words (if horizontal presentation) (default: 25%)
/right_x:						the right coordinate  of the words (if horizontal presentation) (default: 75%)
/top_y:							the top coordinate  of the words (if vertical presentation) (default: 25%)
/bottom_y:						the bottom coordinate  of the words (if vertical presentation) (default: 25%)

Note: 
- for horizontal presentations, the y-coordinate is automatically set to 50%.
- for vertical presentations, the x-coordinate is automatically set to 50%.