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									Emotion N-Back Task
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software LLC
Date: March, 2012
last updated: 06-22-2018 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Copyright © 06-22-2018 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script implements a an emotion N-back based on:
										
Ladouceur, C. D., Silk, J. S., Dahl, R. E., Ostapenko, L., Kronhaus, D. M., & Phillips, M. L. (2009). 
Fearful faces influence attentional control processes in anxious youth and adults. Emotion, 9(6), 855-864.
http://dx.doi.org/10.1037/a0017747

The script uses the general framework of the Inquisit Letter N-back script.

										

											  *Task*
In the 1-key single n-back task, participants are shown a sequence of stimuli (here: a sequence of white letters
on a black background) and are asked to indicate whether the currently presented stimulus fulfills the following criteria:

for N=0 trials:
- is the letter the letter M? If so (it's a target), and press "A". If not, don't respond.

for N=1 trials:
- is the letter the same as the one that preceded it? If so (it's a target), and press "A". If not, don't respond.
(note: 1-back is not run by this script)

for N=2 trials:
- is the letter the same as the one presented two trials before? If so (it's a target), and press "A". If not, don't respond.

During test trials, the center letters are flanked by:
- happy faces
- fearful faces
- neutral faces
- no faces


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

(1) Raw data file: 'emotionNback_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:						the name of the current block
values.TotalBlocks:				the total number of experimental blocks run
trialcode:						the name of the current trial
/emotion:						0 = practice; 1 = happy faces; 2 = fearful faces
starttrialcounter:				keeps track of how many start trials have been run
/ITI:							intertrial interval (presents a fixation cross); mean duration = 3500ms (see Editable Lists)
stimulusitem:					the letter presented
stimulusnumber: 				the item number of the presented letter
/flankerStim:					stores the currently selected flanker Stim
values.currenttarget:			the item number of the current target
response:						the response of the participant
									57 = spacebar press
									30 = A
									0 = no response
/responseCat:					"hit", "miss", "FA", "CR"
correct:						the correctness of the response
latency:						in ms; measured from onset of letter until letter disappears


(2) Summary data file: 'emotionNback_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)

/hitrate_N0_ctrl:				hitrate of pressing spacebar for targets in N=0 condition that are flanked by ctrl faces
/hitRT_N0_ctrl:					mean latency of correctly pressing spacebar for targets in N=0 condition that are flanked by ctrl faces
/FArate_N0_ctrl:				false alarm rate of incorrectly pressing spacebar for nontargets in N=0 condition that are flanked by ctrl faces

/hitrate_N0_happy:				hitrate of pressing spacebar for targets in N=0 condition that are flanked by happy faces
/hitRT_N0_happy:				mean latency of correctly pressing spacebar for targets in N=0 condition that are flanked by happy faces
/FArate_N0_happy:				false alarm rate of incorrectly pressing spacebar for nontargets in N=0 condition that are flanked by happy faces

/hitrate_N0_fearful:			hitrate of pressing spacebar for targets in N=0 condition that are flanked by fearful faces
/hitRT_N0_fearful:				mean latency of correctly pressing spacebar for targets in N=0 condition that are flanked by fearful faces
/FArate_N0_fearful:				false alarm rate of incorrectly pressing spacebar for nontargets in N=0 condition that are flanked by fearful faces

/hitrate_N0_neutral:			hitrate of pressing spacebar for targets in N=0 condition that are flanked by neutral faces
/hitRT_N0_neutral:				mean latency of correctly pressing spacebar for targets in N=0 condition that are flanked by neutral faces
/FArate_N0_neutral:				false alarm rate of incorrectly pressing spacebar for nontargets in N=0 condition that are flanked by neutral faces

/hitrate_N2_ctrl:				hitrate of pressing spacebar for targets in N=2 condition that are flanked by ctrl faces
/hitRT_N2_ctrl:					mean latency of correctly pressing spacebar for targets in N=2 condition that are flanked by ctrl faces
/FArate_N2_ctrl:				false alarm rate of incorrectly pressing spacebar for nontargets in N=2 condition that are flanked by ctrl faces

/hitrate_N2_happy:				hitrate of pressing spacebar for targets in N=2 condition that are flanked by happy faces
/hitRT_N2_happy:				mean latency of correctly pressing spacebar for targets in N=2 condition that are flanked by happy faces
/FArate_N2_happy:				false alarm rate of incorrectly pressing spacebar for nontargets in N=2 condition that are flanked by happy faces

/hitrate_N2_fearful:			hitrate of pressing spacebar for targets in N=2 condition that are flanked by fearful faces
/hitRT_N2_fearful:				mean latency of correctly pressing spacebar for targets in N=2 condition that are flanked by fearful faces
/FArate_N2_fearful:				false alarm rate of incorrectly pressing spacebar for nontargets in N=2 condition that are flanked by fearful faces

/hitrate_N2_neutral:			hitrate of pressing spacebar for targets in N=2 condition that are flanked by neutral faces
/hitRT_N2_neutral:				mean latency of correctly pressing spacebar for targets in N=2 condition that are flanked by neutral faces
/FArate_N2_neutral:				false alarm rate of incorrectly pressing spacebar for nontargets in N=2 condition that are flanked by neutral faces


EXPERIMENTAL SET-UP:

Practice:
- After instructions, participants work through 1 block of each
- 0-back; 2-back (currently the settings are set to run them in sequence starting with a 0-back)
- default: 9 trials with 3 target trials; 6 nontarget trials 
- default: feedback is presented during practice

Test:
- 8 blocks: 2 level of N (0,2) x 4 flanker conditions (no faces, happy faces, fearful faces, neutral faces)
- 3 runs of those 8 blocks:
	* each run starts with condition N=0, no faces
	* remaining 7 blocks are randomly selected

- each block runs 12 trials (+ starttrials that cannot display targets yet) => 4 target trials; 8 non-target trials
- The computer selects randomly 
a) whether it is a target trial or not and 
b) what letter to show if it is not a target trial


Trial Information:
- Each trial presents the letter for 500ms
- An intertrial interval (displays a fixation cross) replaces the center letter. 
Duration is randomly selected from duration starting at 3000ms to 4000ms (steps 100ms) with a mean duration of 3500 (see Editable lists)
- the response window can be set under section Editable Parameters.
CURRENTLY it's set to max.3000ms 


Face Flanker Selection:
Face stimuli are selected randomly without replacement from the current pool of face stimuli for each condition.
Repeats within one block are possible after all possible stims have been selected.
The pool of available images is reset after each block.

STIMULI
stimuli from NimStim set available at
www.macbrain.org (Tottenham et al., 2009)

female participants: 2, 5, 6, 7, 8, 9, 13, 14, 18, and 19; 
male participants: 21, 23, 24, 27, 28, 30, 33, 37, 41, and 42) taken from the . 
All images are 800 x 600 pixels and cropped into an oval shape
(all open mouthed expressions)

INSTRUCTIONS
intro: instructions are presented as images 
They are contained in 3 different helper scripts. Depending on the size of the monitor, 
differently sized images are selected.

test instructions: see item.flankerInstructions, can be edited in this script


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:

debugmode = 0							debugmode = 1: targetalerts are shown on screen, 
										debugmode = 0, no targetalerts are shown (default)
/stimulusPresentationtime:				the presentation time (in ms) of the stimuli (default: 500ms)
/ startFixation:						the duration (in ms) of the fixation cross that is presented at the start of each block (default: 3500ms)

/RW:									max. response window (in ms) after onset of center letter (default: 3000ms)
										Note: the response window cannot be longer than stimulus presentation time (500) + shortest ITI (3000)

/letterSize:							proportional letter size
/fixationCrossSize:						proportional fixation cross size
/picSize:								proportional size of the flanker images
/flankerLetterSize:						proportional size of the flanker letters
/flankerLeft:							proportional position of the left flanker
/flankerRight:							proportional position of the right flanker


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