Pallidal activity is involved in visuomotor association learning in monkeys

In order to examine whether the basal ganglia are involved in arbitrary visuomotor association, we recorded neuronal activity in the internal segment of the globus pallidus (GPi) of monkeys during a conditional visuomotor learning task. Two monkeys were presented a cueing visual stimulus, and following a delay period required to push, pull or turn a manipulator according to the cue. GPi neurons showed changes in activity during the delay period when the animals performed the task on the basis of a familiar stimulus-response association. Those changes in delay activity were enhanced as the monkeys were learning a new visuomotor association. The enhancement of the changes was selective to a following response. These results suggest that the basal ganglia are involved in arbitrary visuomotor association, especially during the learning of new associations.