Neuron activity in the monkey striatum of identifies integration sequential actions into functional blocks.

Spike activity in monkey striatum (putamen) neurons was recorded during the performance of a complex multistep operant task. Tonic responses propagating beyond a single action were recorded, along with phasic responses seen within a given action. The tonic type of response was recorded in 132 of 148 cells. Only 11 of these neurons showed exclusively this type of activity. The beginnings and ends of tonic responses were generally associated with key moments in the behavior, corresponding to the triggering and completion of immediate aims during the performance of the behavioral program as a whole. These results provide evidence that the role of the striatum is not limited to controlling single sequentially performed actions, but spreads to the whole structure of a behavioral act.