LOCALIZATION OF CEREBRAL ELECTRICAL ACTIVITY: THE ACOUSTIC CORTEX OF CAT

Abstract

The Laplacian of electrical potentials on the cerebral surface (a measure of current flow perpendicular to the surface) was recorded by use of a 5 element electrode array. The distribution of evoked responses to an auditory click was more localized and sharply defined by the Laplacian recording than by the conventional "monopolar" recording. Using Laplacian activity, the acoustic cortex of cat was divided into 4 regions on the bases of stability and latency of the responses and on the recovery of excitability following a response. The extent and location of these divisions were in general agreement with those suggested by detailed anatomical analyses of the same area by other workers.