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									FLANKER TEST - Arrow Version
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 03-01-2013
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 an arrow version of the Flanker Test (used with children) based on:

Ridderinkhof, K. R., van der Molen, M. W., Band, P. H., & Bashore, T. R. (1997). Sources of interference 
from irrelevant information: A developmental study. Journal of Experimental Child Psychology, 65, 315–341 (Experiment 2).

NOTE: earlier versions of this script implemented the complete design of Ridderinkhof et al (1997);
the current version simplifies the design by eliminating 3 within-variables:
1. different sized targets (targets will be the same size as distractors)
2. different key-arrow pointing mappings (only consistent key-arrow pointing mappings used in this script)
3. variable vs. fixed cue-target SOAs (only fixed SOAs used in this script)



											  *Task*
Participants see 5 arrows in the middle of the screen inside a box. They have to decide whether the central arrow 
points right or left. The central arrow in this experiment is either smaller or bigger than the surrounding arrows.
The surrounding arrows (=flankers) either point to same direction or the opposite direction. 


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

(1) Raw data file: 'ArrowFlankerTest_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 
/practice:						0 = test block; 1 = practice block
blockcode, blocknum:			the name and number of the current block
/blockcount:					counts the blocks

trialcode, trialnum: 			the name and number of the currently recorded trial
									(Note: not all trials that are run might record data) 

/trialcount:					counts all test trials
/congruence:					determines the state of the flankers (1 = congruent (target and flanker point in the same direction), 2 = incongruent)
/selecttarget:					itemnumber of the current target stimulus
								1 = target points to right; 2 = target points to left
/selectflanker:					itemnumber of the current flanker stimuli
response:						the participant's response (scancode of response button)
correct:						the correctness of the response (0 = error; 1 = correct)
latency: 						the response latency (in ms); measured from onset of target to response (or trial timeout)

(2) Summary data file: 'ArrowFlankerTest_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; 1 = script was completed (all conditions run)
/blockcount:					counts the blocks
/propcorrect:					overall proportion correct (test trials only)				
/meanRT:						overall mean latency (in ms) of correct responses (test trials only)
/propcorrect_congruent:			proportion correct for all congruent trials
/propcorrect_incongruent:		proportion correct for all incongruent trials
/meanrt_congruent: 				mean latency (ms) of correct responses to congruent targets
/meanrt_incongruent: 			mean latency (ms) of correct responses to incongruent targets


EXPERIMENTAL SET-UP:
2 flanker congruence (congruent vs. incongruent), tested within

1 Practice Block: runs 24 congruent and 24 incongruent trials with errorfeedback
1 Test Block: runs 48 congruent and 48 incongruent trials with optional errorfeedback (+ 4 prefatory trials)

Trial Sequence:
target cue (presents the empty box: 1000ms) -> distractors and targets (max.1750ms) -> variable intertrial interval (total duration of one trial: 2750ms)

STIMULI
Type
* cue: an empty rectangle
* stimuli: 5 arrows pointing right or left (flanker, flanker, target, flanker, flanker)
Stimuli can be edited under section Editable Stimuli
The default font used is Arial for all stimuli. Go to STIMULI to change the default font if needed.


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:

Stimuli Dimension:	USE THESE DIMENSION TO FINE TUNE THE FLANKER/TARGET PRESENTATION ON YOUR MACHINE
/flankerheight:							sets the height of the flanker/target stimuli (default: 7%).
/spacingfactor:							this factor together with flankerheight determines the spacing of the
										flankers (default: 2.75)
/increaseboxfactor:						given the flankerheight/spacingfactor, this value sets how much the surrounding box
										needs to increase (default: 3.25)

Experimental Set-up:
/responsekey1:							sets the response key 1 (on left side of keyboard)  (default: 16, q-key)
/responsekey2:							sets the response key 2 (on right side of keyboard) (default: 25, p-key)
/feedback_experiment:					1 = feedback for practice and experimental trials; 0 = feedback only during practice (default)
											Note: feedback duration is not included into targetcueSOA

Durations:
/SOA_cuetarget:							sets the fixed SOA (in ms) between cue and target (default: 1000ms)
/SOA_targetcue:							sets the fixed SOA (in ms) between target and cue (default: 1750ms) -> in this script: max. responsetime
										Note: feedback duration NOT included
/feedback_duration:						sets the duration of the feedback trial (default: 1000ms)

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