Pyramidal tract neurons in somatosensory cortex: central and peripheral inputs during voluntary movement.

Recordings with pyramidal tract neurons (PTNs) in the primary somatosensory cortex of the monkey show that these neurons have 3 properties in common with PTNs of primary motor cortex: (1) they exhibit discharge prior to the onset of voluntary movement, (2) their discharge frequency varies as a function of strength of muscular contraction, and (3) they show reflex responses to afferent stimuli that occur during movement. These findings support the view that in addition to its widely recognized role in somesthetic perception, somatosensory cortex has a direct role in the control of movement.