Premotor cortex and preparation for movement.

Many cells in premotor cortex change their activity while a monkey waits before responding. In the present experiment lesions were placed in premotor cortex in order to investigate the information carried by this neuronal activity. The monkeys were trained to make one of two movements depending on the colour of a cue. There were two conditions: in one they could respond when the cue was presented, in the other they had to wait three seconds before responding. The monkeys were then retested after the bilateral removal of premotor cortex. Animals with premotor lesions performed very poorly under both conditions. It is concluded that premotor cortex is concerned with retrieving the response that is appropriate given a particular cue.