Functional activity related to risk anticipation during performance of the Iowa Gambling Task.

Risk anticipation is an important cognitive/emotional component of decision making. The Iowa Gambling Task [Bechara, A., Damasio, A.R., Damasio, H., Anderson, S.W., 1994. Insensitivity to future consequences following damage to human prefrontal cortex. Cognition 50, 7-15], which is the most widely used "risk-anticipation task" in clinical studies, has been demonstrated to be sensitive to lesions involving the ventromedial prefrontal cortex or amygdala. However, the critical neural circuitry involved in this complex task has not yet been fully clarified even in healthy subjects. Using a 3-T scanner, we performed an event-related functional magnetic resonance imaging study in 14 healthy subjects performing the task. The statistical parametric mapping showed that the risk anticipation component (risky decisions minus safe decisions) exclusively activated the medial frontal gyrus. Furthermore, we found a significant interindividual correlation between the task performance and the magnitude of brain activity during risky decisions. These results indicate that the Iowa Gambling Task does recruit the neural circuitry that is critical in decision making under uncertainty, particularly when subjects perceive the risk of their decision.