AUDITORY RESPONSE FIELDS IN ASSOCIATION AND MOTOR CORTEX OF CAT

Abstract

Response fields to click were delimited on the middle suprasylvian and anterior lateral gyri, and on the motor cortex, using chloralose anesthetic. Responses have onset latencies of 15 msec, and amplitudes up to 3 mv. There are 2 foci on the middle suprasylvian gyrus, 1 on the anterior lateral gyrus, and 1 in the precentral motor area. The responses in all these foci are highly correlated in occurrence and amplitude, and represent separate inputs to the cortex. They are all independent of the primary auditory areas, occurring normally after chronic ablation of these regions. The responses have very long unresponsive periods, compared to responses in the primary auditory area, and tend to occur in an all-or-none fashion. A late response (latency 100 msec.) was seen to click over the approximate region of visual n.