The primate premotor cortex fifty years after Fulton.

Fifty years ago, F.M.R. Walshe launched his famous diatribe against J.F. Fulton and his thesis that a premotor area with specialized functions exists within the agranular frontal cortex of primates. Now there is general agreement that the agranular frontal cortex contains at least 3 cortical fields: the primary motor cortex, the supplementary motor cortex, and the premotor cortex. This paper summarizes some of the evidence that the premotor cortex plays a role in the preparation for limb movements and presents speculation concerning the aspects of motor preparation in which the premotor cortex might be involved.