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Julie Stout's Laboratory
Clinical & Cognitive Neuroscience Research
NIDA: National Institute on Drug Abuse
Our research program has developed formal modeling approaches to analyze the performance of complex problems in different clinical populations. One task that has been of major interest and has led to productive research is the Iowa gambling task. The Iowa gambling task, developed by Bechara, Damasio, Tranel and Anderson (1994) has drawn attention in the decision-making literature since patients with pre-frontal ventromedial lesions were found to have poor performance on the task. Poor task performance has also been found in other clinical populations, including drug abusers, Huntington disease patients, and individuals with an antisocial personality disorder. These results suggest that different mechanisms are responsible for the poor task performance exhibited by these clinically different populations.
Recently, Busemeyer and Stout (2002) used a formal model to decompose performance in the Bechara gambling task into learning, motivation, and decision-making components. This approach has been found useful for understanding the different patterns observed in diverse clinical populations. For example, it appears that Huntington patients perform poorly in this task due to a tendency to focus on recent outcomes and to forget outcomes from less recent choices. In contrast, cocaine addicts seem to exhibit poor performance because of their tendency to focus on gains and ignore losses.
Recent research has included developing and validating this approach. One way of doing so is by examining the correlations between parameters of the model and changes in brain activation. Another method is by examining learning, motivation, and decision-making tasks, and analyzing the cross-correlations between the parameters of the model and performance level in these tasks.
For more information about this study, please call the participant inquiry line at (812) 856-0200 or (866) 786-8848.