2002 A pathway in primate brain for internal monitoring of movements

It is essential to keep track of the movements we make, and one way to do that is to monitor correlates, or corollary discharges, of neuronal movement com-mands. We hypothesized that a previously identiÞed pathway from brainstem to frontal cortex might carry corollary discharge signals. We found that neu-ronal activity in this pathway encodes upcoming eye movements and that inactivating the pathway impairs sequential eye movements consistent with loss of corollary discharge without affecting single eye movements. These results identify a pathway in the brain of the primate Macaca mulatta that conveys corollary discharge signals. When the brain initiates a movement, it also generates internal information that is used by sensory systems to adjust for resultant chang-es to peripheral receptors and by motor plan-ning systems to prepare subsequent move-ments (1–7). Information about an impendin