You Can't Play the Iowa Gambling Task with Mother Nature and Win

The Iowa Gambling Task (IGT) was developed as a test of Damasio’s Somatic Marker Hypothesis, which hypothesizes that emotion plays a role in decision-making. The IGT is now widely used to assess the role of emotion in decision-making in clinical populations. However, although Damasio’s experimental results using the IGT were consistent with the Somatic Marker Hypothesis, there is no direct evidence indicating that the IGT measures the contribution of emotion to decision making in the IGT. Specifically, the IGT does not contain direct measures of emotion, it does not manipulate emotion, and it is not an obviously emotional task. There are only indirect implications that it does so because some clinical populations with emotional deficits have poor performance. We argue that further experimental work is needed to show whether or not IGT performance is systematically influenced by emotion.