A quantitative analysis of stimulus- and movement-related responses in the posterior parietal cortex of the monkey.
The posterior parietal cortex (areas 5 and 7) in monkeys has been described as a higher association cortex and as such, area 5 has been attributed a complex somaesthetic function. More recently, a role in the formation of motor commands has been postulated for these two cortical areas. We have been particularly interested in the role area 5 neurons may have in movement initiation. Single neuron activity was recorded in area 5 during the performance of a trained forelimb movement in monkeys and neuronal responses which occurred prior to movement were observed. In the present report, we have examined the neuronal discharge data trial by trial using a technique of data analysis which enabled us to separate the changes in neuronal activity into stimulus- or movement-related responses. Both stimulus- and movement-related responses were identified. The stimulus-related responses were not simple sensory responses since they were also influenced by the timing of the onset of movement. These results suggest that certain area 5 neurons may be involved in the linking of sensory inputs with motor outputs. Cerebrocerebellar loops may be a pathway in this linkage. The latencies of the movement-related responses were such that corollary discharge from the motor cortex may have played a role in this activity. Such corollary discharge may be a form of information used by the animal to execute movement in the absence of peripheral feedback.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001244:Association; D001931:Brain Mapping; D002415:Cats; D002531:Cerebellum / Q000502:physiology; D008959:Models, Neurological; D009043:Motor Activity / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012677:Sensation / Q000502:physiology*