University of Tasmania
Browse

File(s) under permanent embargo

The expectancy valence model of the Iowa Gambling Task: Can it produce reliable estimates for individuals?

journal contribution
posted on 2023-05-18, 07:20 authored by Melissa Humphries, Raimondo BrunoRaimondo Bruno, Karpievitch, Y, Wotherspoon, S
The Expectancy Valence Model (EVM) of the Iowa Gambling Task (IGT) is commonly used in studies to identify the underlying psychological processes responsible for decision making deficits.We show the EVM does not provide clear information about decision making processes at the individual level by fitting the EVM, with individual random effects, to a sample of participants from various drug using populations using Bayesian techniques and to a sample of participants who complete the IGT multiple times. In particular, we show that the individual-level parameter estimates from the model may be bi-modally distributed and hence are inherently ambiguous and have little psychological significance.In an attempt to increase the validity of individual-level parameter estimates, we also considered a 2-parameter version of the EVM in which the consistency parameter was held constant. In the 2-parameter implementation of the EVM, results were clearer and more easily interpretable than when using the traditional EVM.

History

Publication title

Journal of Mathematical Psychology

Volume

64-65

Pagination

17-34

ISSN

0022-2496

Department/School

School of Natural Sciences

Publisher

Academic Press Inc Elsevier Science

Place of publication

525 B St, Ste 1900, San Diego, USA, Ca, 92101-4495

Rights statement

© 2014 Elsevier Inc.

Repository Status

  • Restricted

Socio-economic Objectives

Public health (excl. specific population health) not elsewhere classified

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC