 In the current study, we will investigate differences in MRI responses to outcomes between SC patients and controls, and between subgroups of patients. In particular, we are interested in determining whether MRI responses in components of reward circuits, such as the midbrain, basal ganglia, and orbitofrontal cortex, are attenuated in SC patients, in the context of paradigms that require individuals to detect mismatches between expected and experienced outcomes, and to modify responses based on those mismatches. We hypothesize that learning deficits in SC stem primarily from impairments in the signaling of errors in reward prediction, and that abnormalities in the signaling of errors in reward prediction will be reflected in abnormal stimulus-evoked activation in the primarily in two brain areas in SC patients both DA target areas: prefrontal cortex and the neostriatum. We predict that these signals will relate systematically to performance on a reinforcement-learning task. 