Role of the primate striatum in attention and sensorimotor processes: comparison with premotor cortex.

The present study was aimed at distinguishing neuronal activity associated with shifts of attention from that reflecting motor set. Our behavioural paradigm allowed a given visual stimulus to serve as a cue for the reorientation of spatial attention or as a cue for establishing a motor set, depending on when it occurred during a trial. Other aspects of the paradigm were designed to identify neurones whose activity differed when various stimulus configurations instructed the same action, as well as neurones whose activity differed when two different limb movements were instructed by the same stimulus. We found that many striatal cells discharge preferentially in relation to cues which reorient spatial attention, although they may also discharge after cues which instruct a motor act. In contrast to the dorsal premotor area (PMd, dorsolateral area 6), in both the caudate nucleus and putamen a larger proportion of the neuronal sample reflected both movement direction and stimulus attributes. These results support a role for striatal neurones in both attentional set shifting and the preparation for context-specific actions.