ON AN IPSILATERAL MOTOR EFFECT FROM CORTICAL STIMULATION IN THE MACAQUE MONKEY

Abstract

With dial or light ether anaesthesia, slow time movements of the fingers, and flexion of the fingers, elbow and shoulder have been evoked by stimulation of the motor and premotor cortex of the rhesus monkey at frequencies of 2-4 per sec. Responses are fused, and are not synchronous with the stimulus. The ipsilateral response in the arm was accomplished by clonic movements in the contralateral arm or leg. The optimum current duration of the stimulus was 10 to 20 msecs. for the rising phase, and was the same for both the ipsilateral and contralateral movements.