Anticipating instrumentally obtained and passively-received rewards: a factorial fMRI investigation.

During functional magnetic resonance imaging (fMRI), subjects saw cues signaling probabilities of 1.0, 0.5, and 0 of winning $1 for hitting a subsequent target, and cues signaling similar probabilities of reward delivery requiring no instrumental response. Non-instrumental reward anticipation did not elicit activation. Instrumental reward anticipation activated multiple nodes of the basal ganglia-thalamocortical motor circuit. Ventromesial striatum was activated by joint requirement for an instrumental response together with uncertain (but not certain) reward.