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							IOWA GAMBLING TASK - Modified Version

last updated: 01-14-2016 by K.Borchert ( for Millisecond Software LLC
Copyright © 01-14-2016 Millisecond Software


This sample script implements a version of the modified Iowa Gambling Task as described in:

Cauffman, E., Shulman, E.P, Steinberg, L., Claus, E., Marie T. Banich, M.T.,  Sandra Graham, S., & Jennifer Woolard, J. (2010). 
Age Differences in Affective Decision Making as Indexed by Performance on the Iowa Gambling Task.
Developmental Psychology, Vol. 46, No. 1, 193–207.

This script builds on the original Millisecond Software script "IowaGamblingTask.iqx" based on
Bechara A., Damasio A. R., Damasio H., Anderson S. W. (1994). 
Insensitivity to future consequences following damage to human prefrontal cortex. Cognition, 50, 7-15 .

Participant are presented 4 decks of cards. One of the deck of cards has a yellow arrow above it.
Participants have to decide to 'play' this deck of cards to possibly win some money or pass up the 
opportunity (to make sure to not lose any money already won). If they decide to play they can win money,
lose money, or neither lose nor win money. If they pass, they neither lose nor win money.
The goal is to win as much money as possible. The 4 different decks are attached with different
win probabilities: 2 of the decks have higher wins and even higher losses (being disadvantageous overall) 
and 2 decks have lower wins but even lower losses (being advantageous overall).

The default data stored in the data files are:

(1) Raw data file: 'ModifiedIGT_raw*.iqdat' (a separate file for each participant)

build:							Inquisit build
computer.platform:				the platform the script was run on
date, time, subject:			date and time script was run with the current subjectnumber 
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) 
values.cardoffered: 			number of cards offered
values.groupnumber: 			the groupnumber (1-4) the subject was randomly assigned to	(=> 4 different placements of decks)			
parameters.defaultresponse: 		if no response occurs, 	defaultresponse = 1 => 'Pass' response; defaultresponse = 2 => 'Play' response
values.targetdeck:				the current targetdeck with an arrow

response:						the participant's response
values.response:				1 = pass; 2 = play (if no response is given values.response evaluates to the defaultresponse)
latency: 						the trial latency
values.forcedwins4:				current number of guaranteed wins that will occur when participant decides to 'play' per deck
values.gain/values.loss/values.netchange:  trial gain/trial loss/net win			feedback that participant received
values.currenttotal:			the running total for participant
expressions.percent_goodplay_block: 	percentage of play-response to advantageous decks per block
values.number_goodplay_block:  			number of times participant chose an advantageous deck per block
values.total_gooddeck_block: 			number of times an advantageous deck was presented
(same measures for disadvantageous blocks)

expressions.netscore_block:				difference score of 'good-decisions' and 'bad-decisions' (overall performance measure, per block)

(2) Summary data file: 'ModifiedIGT_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)
expressions.percent_goodplay:	percentage of play-response to advantageous decks across blocks
expressions.percent_badplay:	percentage of play-response to disadvantageous decks across blocks
expressions.netscore_total: 	difference score of 'good-decisions' and 'bad-decisions' (overall performance measure, across blocks)

* The game is set up to play 6 blocks of 20 trials (5 trials per deck) => 30 trials per deck total
* A deck is randomly selected for each trial.
* The four decks are randomly assigned a (permanent) screen location. 
* By default, in this script the win/loss probabilities assigned are aligned with the model of "once played, 
cards are NOT returned to the deck" (therefore turning probabilities into actual frequencies)

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:

/playkey: 								scancode of 'play' key (default: 30 -> a)
/passkey:								scancode of 'pass' key (default: 38 -> l)
/playkey_label:							description of play key
/passkey_label:							description of pass key

/decisiontime :							time participant has to decide (default: 4000ms)
/defaultresponse:						if no response occurs, 	defaultresponse = 1 => 'Pass' response
																defaultresponse = 2 => 'Play' response

/number_forcedwins1-					sets the number of definite wins for each deck that occur during the initial trials for that deck
/number_forcedwins4						Example: 
										number_forcedwins1 = 2 => the first play trial for deck 1 that participant can lose is on the third play trial of deck 1
										number_forcedwins1 = 8 => the first play trial for deck 1 that participant can lose is on the ninth play trial of deck 1
										=> guarantees the number of guaranteed win play trials from each deck at the beginning
										(Note: numbers are taken from Cauffman et al (2010), Table 2)

/startamount:							the startamount (default: $2000)

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