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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: 02-22-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 02-22-2022 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
session: with the current session id
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)*
inquisit.version: Inquisit version run
computer.platform: the platform the script was run on (win/mac/ios/android)
startDate: date script was run
startTime: time script was started
subjectid: assigned subject id number
groupid: assigned group id number
sessionid: assigned session id number
elapsedTime: time it took to run script (in ms); measured from onset to offset of script
completed: 0 = script was not completed (prematurely aborted);
1 = script was completed (all conditions run)
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")
