Neuronal activity in the motor and premotor cortices before and after learning the associations between auditory stimuli and motor responses.

In order to assess the effect of learning a conditional motor task on set-related cells of the precentral cortex we recorded a total of 228 task-related cells in awake, behaving primate. A first sample of 54 set-related cells was recorded while the monkey was performing at 54.7 +/- 7.8% and a second sample of 119 set-related cells was recorded at the same stereotaxic coordinates while he was performing at 77.2 +/- 8.7%. After the monkey had learned the association between an auditory signal and a motor response we found a significant increase in the proportion and activity of directional set-related cells in the premotor cortex. Furthermore the proportion of short-latency set-related cells was found to increase in this area. None of those changes were observed in the motor cortex.