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											BIRD TASK


Script Author: Katja Borchert, Ph.D. ( for Millisecond Software, LLC
Date: Nov 2014
last updated:  01-06-2016 by K. Borchert ( for Millisecond Software, LLC

Copyright ©  01-06-2016 Millisecond Software


This script runs the BIRD task as described by:

Daughters, S.B, Reynolds, E.K., MacPherson, L., Kahler, C.W.,  Danielson, C.K., Zvolensky, M. & Lejuez, C.W. (2009). 
Distress tolerance and early adolescent externalizing and internalizing symptoms: The moderating role of gender and ethnicity.
Behaviour Research and Therapy, 47, 198–205.

The Bird task is a child version of the computerized distress tolerance task PASAT-C by Lejuez et al (2003)	
(see Millisecond Software's PASAT-C.iqx)

A green dot appears above 1 out of 10 possible boxes and participants are asked to click the box as fast as possible.
If participants click the box before the trial times out, a bird is set free from its cage and participants win a point.
If participants are not fast enough, the bird remains in the cage and no points are won.
The goal of the game it to win as many points as possible.
Participants work through 3 levels with the last level being the most challenging in terms of timing.
During level 3, participants have the option to quit prematurely (=measure of distress tolerance).

The default data stored in the data files are:

(1) Raw data file: 'BirdTask_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, 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) 
/counttrials:					counts all freebird trials within a level
/dotposition:					(box) 1-10
stimulusitem:					the presented stimuli in order of trial presentation
response:						the participant's response
correct:						the correctness of the response (1 = correct; 0 = incorrect)
latency: 						the response latency (in ms)
/trialdotlatency: 				the max. time the current dot is presented before a new trial is started (used for trial timeout)
/score:							stores the current scorecount

(2) Summary data file: 'BirdTask_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)
/score:							stores the final scorecount
/meandotlatency:				stores the mean dot latency of level 1
/challengelatency:				stores the challenge dot latency (= 1/2 of the mean dot latency in level 1)
/quit:							1 = participant quit level 3 prematurely; 0 = participant did not quit level 3
/level3duration:				stores the time spent on level 3 
/level1correct:					stores the correct responses for level1
/level2Acorrect:				stores the correct responses for level2A
/level2Bcorrect:				stores the correct responses for level2B
/level2correct:					stores the combined correct responses for level 2
/level3correct:					stores the correct responses for level3

3 levels:
Level1: used to calculate participant's mean dot latency (~ latency at which the dot moves that participant can still 'beat'); 3 min duration
Note: the starting dot latency is set at 5000ms.
Success => dot latency is reduced by 500ms (editable parameter)
Failure => dot latency is increased by 500ms
Level2A: uses mean dot latency for 4 min (default timing; can be edited)
Level2B: uses challenge dot latency ( = mean dot latency / 2) for 1 min (default timing; can be edited)
Level3: uses challenge dot latency for 5 min (default timing; can be edited) with the option to quit/escape prematurely

In this script, the feedback (success = bird flies away & happy chirp; failure = bird stays in cage; sad chirp)
takes 100ms (default; can be edited) => therefore the SOA btw. dots = current dot latency + feedback duration).

Stimuli are provided by Millisecond Software and can be exchanged under section
EDITABLE CODE -> Editable Stimuli

Instructions are provided by Millisecond Software in the form of html pages.
Edits can be made in the files directly.
Instructions in this script are self-paced (not on a timer)

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:

/birdincagesize:				sets the size of the bird in the cage picture (default: 40% of canvas height)

Timeouts: sets the block timeouts for the various levels in ms (Note: level 2 is split in level2A and level2B in this script)
/level1_timeout = 180000          	=> 3 Minutes  
/level2A_timeout = 240000			=> 4 Minutes
/level2B_timeout = 60000			=> 1 Minute
/level3_timeout = 300000			=> max. 5 Minutes

/startdotlatency:				sets the start dot latency for Level 1 trials in ms (default: 5000ms)
/level1_dotlatency_adjust:		defines the adjustment to the dot latency during Level1 depending on success (decrease) or failure (increase) in ms (default: 500ms)
/feedbackduration:				sets the duration of the success/failure feedback in ms (default: 100ms)
									=> Stimulus Onset Asynchrony (dots) = current dot latency + feedbackduration

/winpoints:						sets how many points participants win for each successful response (default: 1)

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