Iowa Gambling Task - IGT

Technical Manual

Last Modified: January 26, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This sample script implements the Iowa Gambling Task (IGT). The IGT task assesses risk learning by utilizing rewards and punishment in an uncertain simulated real-life decision making context

The implemented procedure is 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 .

Duration

5 minutes

Description

Participant are presented 4 decks of cards and are asked to select a card from one of the 4 decks with their mouse. By turning over the cards, participants can win money but also lose money. The four different decks can be categorized as advantageous (overall more wins than losses) or disadvantageous (overall more losses than wins).

Procedure

• The game is set up to play 1 block of 100 trials
• The four decks are assigned a (permanent) screen location by groupnumber (4 different groups).
regardless of actual screen presentation:
deck1/deck2 = disadvantageous
deck3/deck4 = advantageous
• 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 over the course of 10 selections of each deck;
see more info under section EXPRESSIONS)
• the script collects performance data in blocks of 20 trials

Stimuli

provided by Millisecond - can be edited under section Editable Stimuli

Instructions

provided by Millisecond - can be edited under section Editable Instructions

Summary Data

File Name: iowagamblingtask_summary*.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
startDate Date the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
elapsedTime Session duration in ms
completed 0 = Test was not completed
1 = Test was completed
deckOrderGroup The experimental deck group (1-4) the subject was randomly assigned to
(refers to order of the advantageous (deck3, deck4) and disadvantegeous (deck 1, deck2)
decks on the screen)
group1: deck1(D), deck2(D), deck3(A), deck4(A)
group2: deck3(A), deck1(D), deck4(A), deck2(D)
group3: deck4(A), deck3(A), deck2(D), deck1(D)
group4: deck2(D), deck4(A), deck1(D), deck3(A)
countDeck1Select-
countDeck4Select Count all the actual deck1-deck4 choices across all blocks
propDeck1Select-
propDeck4Selectt Proportion of specific deck selections
deck1 always refers to deck1 and not specific deck location
countAdvantageTotal Counts the total number of advantageous selections (deck 3 & deck 4)
countDisadvantageTotal Counts the total number of disadvantageous selections (deck 1 & deck 2)
net Difference btw. total number of advantageous and disadvantageous selections
(positive NET -> overall more advantageous selections)
per blocks of 20 trials
countAdvantage1 Counts the number of advantageous selections (deck 3 & deck 4) during trials 1-20
countDisadvantage1 Counts the number of disadvantageous selections (deck 1 & deck 2) during trials 1-20
net1 Difference btw. number of advantageous and disadvantageous selections during trials 1-20
countAdvantage2 Counts the number of advantageous selections (deck 3 & deck 4) during trials 21-40
countDisadvantage2 Counts the number of disadvantageous selections (deck 1 & deck 2) during trials 21-40
net2 Difference btw. number of advantageous and disadvantageous selections during trials 21-40
countAdvantage3 Counts the number of advantageous selections (deck 3 & deck 4) during trials 41-60
countDisadvantage3 Counts the number of disadvantageous selections (deck 1 & deck 2) during trials 41-60
net3 Difference btw. number of advantageous and disadvantageous selections during trials 41-60
countAdvantage4 Counts the number of advantageous selections (deck 3 & deck 4) during trials 61-80
countDisadvantage4 Counts the number of disadvantageous selections (deck 1 & deck 2) during trials 61-80
net4 Difference btw. number of advantageous and disadvantageous selections during trials 61-80
countAdvantage5 Counts the number of advantageous selections (deck 3 & deck 4) during trials 81-100
countDisadvantage5 Counts the number of disadvantageous selections (deck 1 & deck 2) during trials 81-100
net5 Difference btw. number of advantageous and disadvantageous selections during trials 81-100

Raw Data

File Name: iowagamblingtask_raw*.iqdat

Data Fields

NameDescription
build Inquisit version number
computer.platform Device platform: win | mac |ios | android
date Date the session was run
time Time the session was run
subject, group, With the current subject/groupnumber
session Session number
deckOrderGroup The experimental deck group (1-4) the subject was randomly assigned to
(refers to order of the advantageous (deck3, deck4) and disadvantegeous (deck 1, deck2)
decks on the screen)
group1: deck1(D), deck2(D), deck3(A), deck4(A)
group2: deck3(A), deck1(D), deck4(A), deck2(D)
group3: deck4(A), deck3(A), deck2(D), deck1(D)
group4: deck2(D), deck4(A), deck1(D), deck3(A)
blockCode Name of the current block
blockNum Number of the current block
trialCode Name of the current trial
trialNum Number of the current trial
cardsSelected Counts the number of card selections (across all blocks)
card1ItemNumber-
card2ItemNumber Store the itemnumber of the card face that needs to be presented on screen for each of the 4 decks
response The participant's response
(e.g. which deck was chosen; the response "deck1" refers to the actual disadvantegous deck1
and not the position of the deck on the screen)
responseCategory "advantageous" vs. "disadvantageous"
latency The response latency (in ms)
gain Stores the trial's gain depending on choice
loss Stores the trial's loss depending on choice
currentTotal Stores the current amount of coins won

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
startamount The amount of money owned at the start of the game; startamount (default) = 2000
showCardInfo Shows information about number of cards played/how many more to come