Much of our knowledge of how reward information is processed in the brain comes from a rich animal literature. Recently, the advancement of neuroimaging techniques has allowed researchers to extend such investigations to the human brain. A common finding across species and methodologies is the involvement of the striatum, the input structure of the basal ganglia, in a circuit responsible for mediating goal-directed behavior. Central to this idea is the role of the striatum in the processing of affective stimuli, such as rewards and punishments. The goal of this article is to probe the human reward circuit, specifically the striatum and its subdivisions, with an emphasis on how the affective properties of outcomes or feedback influence the underlying neural activity and subsequent decision making. Discussion will first focus on anatomical and functional considerations regarding the striatum that have emerged from animal models. The rest of the article will center on how human neuroimaging studies map to findings from the animal literature, and how more recently, this research can be extended into the social and economic domains.