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										Game of Dice Task (GDT)
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Script Author: David Nitz (dave@millisecond.com) for Millisecond Software LLC for Millisecond Software, LLC
last updated:  11-11-2019 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 11-11-2019 Millisecond Software

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BACKGROUND INFO 	
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	This script implements the 'Game of Dice Task' (GDT), a test of risky gambling decisions, 
	with and without feedback (optional).
	
	The implemented procedure is based on:
	
	(with feedback):
	Brand, M., Fujiwara, E., Borsutzky, S., Kalbe, E., Kessler, J., & Markowitsch, H.J. (2005). 
	Decision-making deficits of Korsakoff patients in a new gambling task with explicit rules -
	associations with executive functions. Neuropsychology, 19, 267–277.

	and
	
	(without feedback)
	Brand, M. (2008). Does the feedback from previous trials influence current decisions? A study on the role 
	of feedback processing in making decisions under explicit risk conditions. 
	Journal of Neuropsychology, 2, 431-443.

	
	By default the script plays the version WITH feedback. To play the version WITHOUT feedback, go to
	Editable Task Parameters -> parameters.GDTversion and change to parameters.GDTversion = 2.

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TASK DESCRIPTION	
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A dice is being rolled and participants have to bet on the outcome.
They have the choice between 4 different kinds of bets:
- a single bet (betting on a specific dice face: earns the most money if correct, but loses the most if incorrect (very risky bet)
- a dual bet (betting on two possible dice faces: if either one of them is rolled, it's a win. earns/loses slightly less than single bet (risky bet)
- a triple bet (betting on three possible dice faces: earns/loses less than dual bet (safe bet)
- a quadruple bet (betting on four possible dice faces: ears/loses the least (safest bet)
Participants can quit at any point before the default rounds (18) are played.

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DURATION 
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the default set-up of the script takes appr. 5 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: 'gameofdicetask_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

parameters.GDTversion:			1 = original version with feedback (default); 2 = version without feedback

blockcode, blocknum:			the name and number of the current block (built-in Inquisit variable)
currentround:					stores the current round number
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. 
																				
latency: 							the response latency (in ms)
chosen:							the selected dice faces participants is betting on (example: "1", "12", "123", "1234")
throw:							the dice face thrown

row:								reflects participant's betting choice: 
									For "singles" ("1", "2", etc.) values.row = 1
									For "doubles" ("12", "34", etc.) values.row = 2 
									For "triples" ("123", "456") values.row =3
									For "quadruples" ("1234", etc.) values.row = 4
									
currentbet:						the amount of money currently bet on values.chosen
gain:								amount of money won or lost in the current round (e.g. -500)
account_balance:				Amount participant owns
single:								counts how many times participant has bet on 1 specific dice face
double:							counts how many times participant has bet on 2 possible dice faces
triple:								counts how many times participant has bet on 3 possible dice faces
quadruple:						counts how many times participant has bet on 4 possible dice faces
safe:								counts how many times participants selected a safe bet (bets on 3 or 4 dice faces)
risky:								counts how many times participants selected a risky bet (bets on 1 or 2 dice faces)

net_score:						reflects the number of safe (bets on 3 or 4 numbers) vs. risky (bets 
									on 1 or 2 numbers) choices. It is computed as number of safe bets minus number of risky bets.
								
wins:								adds the number of winning bets
losses:							adds the number of losing bets


(2) Summary data file: 'gameofdicetask_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)
								
parameters.GDTversion:			1 = original version with feedback (default); 
									2 = version without feedback
								
account_balance:				Amount participant owns
single:								counts how many times participant has bet on 1 specific dice face
double:							counts how many times participant has bet on 2 possible dice faces
triple:								counts how many times participant has bet on 3 possible dice faces
quadruple:						counts how many times participant has bet on 4 possible dice faces
safe:								counts how many times participants selected a safe bet (bets on 3 or 4 dice faces)
risky:								counts how many times participants selected a risky bet (bets on 1 or 2 dice faces)

net_score:						reflects the number of safe (bets on 3 or 4 numbers) vs. risky (bets 
									on 1 or 2 numbers) choices. It is computed as number of safe bets minus number of risky bets.
								
wins:								adds the number of winning bets
losses:							adds the number of losing bets


* 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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* by default max. 18 rounds get played (set under section Editable Parameters)
* participant can quit at any point
* the faces are selected randomly without replacement from list.rolldice
* by default, participant get feedback of the dice throw and updating of account information

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STIMULI
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Revised instructions, visuals and other procedural details thanks to the helpful and generous input from the original authors.

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INSTRUCTIONS 
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Revised instructions, visuals and other procedural details thanks to the helpful and generous input from the original authors.

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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:

	GDTversion:				1 = original version with feedback (default); 
							2 = version without feedback
								Note: adjust instructions accordingly under section Editable Instructions
								
	nrounds_gdt: 			Number of rounds in feedback version (must be a multiple of 6); default is 18
	nrounds_gdt_nf: 			Number of rounds in no-feedback version (must be a multiple of 6); default is 18
								IMPORTANT: When in- or decreasing the number of rounds in either version, adjust 
								the number of items in list.rolldice accordingly.
								
	account_balanceStart: 	Amount of points / Money at Task Onset
	currency: 				Exchange "$" with "€", "£", "¥", etc.
	gainsingle: 				Amount to be won/lost when betting on a single number (e.g. "3")
	gaindouble: 				Amount to be won/lost when betting on a combination of two numbers (e.g. "5 or 6")
	gaintriple: 				Amount to be won/lost when betting on a combination of three numbers (e.g. "1 or 2 or 3")
	gainquadruple:			Amount to be won/lost when betting on a combination of four numbers (e.g. "2 or 3 or 4 or 5")