Individual Differences in Performance on Iowa Gambling Task are Predicted by Tolerance and Intolerance for Uncertainty

Iowa Gambling Task (IGT) is frequently used to index individual differences in decision-making under uncertainty, particularly in atypical (clinical) populations. However, it is rarely analyzed as a learning task, and research on the predictors of performance on the IGT in normative populations is scarce. Here, we focused on tolerance and intolerance for uncertainty as two traits that could potentially influence subjects’ IGT performance. Using mixed modeling analysis of longitudinal experimental data (n=60, 5 blocks) we showed that tolerance for uncertainty predicted the initial level of risk in IGT as manifested in the proportion of “bad decks” chosen; at the same time, intolerance for uncertainty predicted explorative learning in IGT as manifested in the number of deck switches after a loss and its decline over the course of the experiment. The results are discussed in the context of viewing IGT as capturing a set of dynamic decision making processes that rely on learning, risk taking, and exploration.