Decision-Making Skills in Autism Spectrum Disorders: Performance on the Iowa Gambling Task

Background:

The Iowa Gambling Task (IGT) is a decision-making task that requires implicit learning and executive function abilities. Performance on the IGT is related to the basal ganglia and frontal cortex of the brain, areas that are impaired in individuals with Autism Spectrum Disorders (ASD). Johnson, et al. (2006) used a computerized version of the IGT in adolescents with Asperger’s disorder and typical development and found that participants with Asperger’s disorder had an unusual selection pattern characterized by frequent shifts between decks.

Objectives:

This project examined whether individuals with ASD show implicit learning by increasingly choosing from advantageous decks across time rather than simply examining the average performance across all trials to compare individuals with ASD and typical development (TD).

Methods:

Participants were 14 high-functioning adolescents and young adults with ASD and 18 TD adolescents and young adults matched on age and verbal ability. Participants completed a computerized IGT composed of six blocks of 25 selections from four decks of cards that differed with respect to advantageousness (the amount of gain possible) and frequency of a loss.

Results:

Preliminary results indicate that individuals with TD showed strong early learning, selecting from advantageous decks 69% of the time by the 3^rd block. Individuals with ASD showed slower, more gradual learning, selecting from advantageous decks 57% of the time by the 3^rd block. This difference between diagnostic groups approached significance, p=.08, partial eta squared=.096.

Conclusions:

Preliminary results indicated differences between participants with ASD and TD in implicitly learning to make advantageous choices. Further data analyses are being conducted to examine performance and learning related to other aspects of the IGT such as the impact of frequency of loss and deck shifting. Funding provided by the University of Alabama Psychology Department and Graduate School.