Behavioral inhibition is a temperamental trait characterized in infancy and early childhood by a tendency to withdraw from novel or familiar stimuli. Recent neuroimaging research indicates that BI individuals have atypical neural responses to information regarding reward and punishment in the striatum and amygdala--regions of the brain that receive information about salient stimuli and use it to guide motivated behavior. Activation to rewarding and punishing stimuli in these regions follows a "prediction error" pattern. My research examines whether behaviorally inhibited young adults display atypical prediction error responses, and whether these responses are specific to rewarding or aversive events. Prediction error signals are theorized to be critical for approach and avoidance learning, and a second study examined probabilistic approach and avoidance learning in the same sample, examining differences in approach and avoidance learning between behaviorally inhibited and non-inhibited individuals, and the relation between learning and neural prediction error signals to reward and punishment.