The goals of my proposed research are to use functional magnetic resonance imaging to (1) clarify the role of the orbitofrontal cortex (OFC) in using reinforcements to guide reward-seeking behavior, and (2) test the hypothesis that individual differences in impulsivity are reflected in OFC activity during reward-seeking behavior. Evidence suggests that OFC is critically involved in reward-based motivation and reinforcement, but the precise function of this region remains debated. I will test the hypothesis that OFC mediates the relationship between reinforcements of current behavior and adjustments in future reward-seeking risk-taking behavior. Two existing theoretical frameworks make differing predictions about how OFC activity would relate to adjustments in behavior, and my experiment is designed to test these predictions. Further, researchers have hypothesized that highly impulsive individuals, who are at risk for developing addictive disorders, fail to use contextual information to guide their behavior. I will test the hypothesis that this is reflected both in the ability to use reinforcements to guide future behavior, and in the extent to which OFC is recurited during these behavioral adjustments.