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									DIGITAL FOOD DISPENSER - Spacebar operated
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 07-07-2015
last updated:  11-08-2019 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 11-08-2019 Millisecond Software

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BACKGROUND INFO 	
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This script implements a Digital Food Dispenser similar to the one described in:

van Koningsbruggen, G.M., Veling, H., Stroebe, W. & Aarts, H. (2014). Comparing two psychological interventions in
reducing impulsive processes of eating behaviour: Effects on self-selected portion size.
British Journal of Health Psychology, 19, 767–782.

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TASK DESCRIPTION	
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Participants view a food dispenser. By pressing the Spacebar down they "open" the Food Dispenser.
By lifting the Spacebar they "close" the Food Dispenser and end the session.

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DURATION 
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Max Duration: 2minutes
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DATA FILE INFORMATION 
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The default data stored in the data files are:

(1) Raw data file: 'digitalfooddispenser_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. 
										
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)
currentresponseduration:			the amount of time the Spacebar was pressed (in ms) for the current food dispenser
currentpoints:					stores the points of the current food dispenser session (resets for each food dispenser)
totalpoints:						stores the points earned across food dispensers


(2) Summary data file: 'digitalfooddispenser_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)

maxpoints:						the maximum number of points that can be gained for one food dispenser (default: 500)
meanresponseduration:			mean response duration in ms (how long Spacebar was pressed on average) across dispensers
meanpoints:						mean points gained across dispensers (Max: 500)

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EXPERIMENTAL SET-UP 
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* 2 trials: 1 food dispenser with cherries and 1 food dispenser with bananas; order is randomly determined
* Spacebar down: the dispenser "opens": fruit pieces "fall out" and a gray cover starts to cover the food dispenser
to simulate that it empties out
* Spacebar up: the dispenser "closes" -> trial comes to an end
* every 100ms (default) of pressing the Spacebar earns the participant 1 point => max. 500 points can be earned (then the dispenser is empty)

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STIMULI
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provided by Millisecond Software

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INSTRUCTIONS 
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provided by Millisecond Software; edit 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:

/increaseinterval:			another point is added for every 100ms (default; Note: should not be set lower than vertical refreshrate of monitor which is ~17ms for a 60Hz monitor)
						that the Spacebar is NOT pressed
						
/maxpoints:				the maximum number of points that can be gained (default: 500)

Note: the product of increaseinterval and maxpoints controls how long it takes to 'drain' the dispenser completely

/finalcoverheight:			the height of the final gray cover (Note: should only be messed with if different pictures are used)