Human motor cortex: sensory input data from single neuron recordings.

Recordings were made from single neurons in the hand area of the human motor cortex while peripheral physiologic stimuli were applied. Such cells responded only to active and passive hand movements. Tactile and autditory (click) stimuli were itneffective. The majority of cells were activated only by movements of the contralateral hand, but a significant number (4 of 16) could be excited if a given movement was made by either hand. Of the cells responding to active movement, some showed an increased discharge before onset of the voluntary action. Such cells were excited by the same movement executed passively, a result that indicates sensory feedback from receptors activated by that movement.