The Supplementary Motor Area of the Cerebral Cortex

JUST IN front of the motor area of the cerebral cortex of man there is a supplementary representation of movements. This supplementary area is rather well circumscribed and is situated largely within the longitudinal interhemispheral fissure (Fig. 1). During the past several years we have seen a number of patients whose difficulties have necessitated surgical exploration and cortical stimulation within the longitudinal fissure. The findings cast new light upon the problem of cortical representation of motor and sensory function. This paper is an analysis of our observations on the properties of the superior and mesial intermediate precentral cortex in man. The results of local electrical stimulation and the patterns of focal seizures due to discharge in the area are presented, and an attempt is made to interpret the findings in terms of function. In addition, the results of an experimental approach to the analogous area in monkeys is reported. HISTORICAL