MOVEMENT-RELATED POTENTIALS ASSOCIATED WITH SINGLE AND REPETITIVE MOVEMENTS RECORDED FROM HUMAN SUPPLEMENTARY MOTOR AREA

To clarify the differences of movement-related potentials (MRPs) betwe en single and repetitive movements, MRPs with finger movements were re corded from subdural electrodes chronically implanted on the supplemen tary motor area (SMA) in 2 patients, and MRPs with foot movements were recorded simultaneously from the SMA and the primary motor foot area in 1 patient. Repetitive movements did not elicit larger pre-movement potentials in the SMA as compared with single movements in all 3 patie nts. In the negative motor area, where electrical stimulation elicited inhibitory responses of voluntary movements and which is located at t he rostral part of the SMA, pre-movement potentials to either single o r repetitive movements were of approximately equal amplitude in 1 out of 3 patients. It is, therefore, most likely that the SMA plays an equ ally significant role in preparation for single and repetitive volunta ry movements.