ON THE PROPAGATION OF CERTAIN CORTICAL POTENTIALS

Abstract

The presence in the cortex of a secondary response to sciatic stimulation homolateral to a hemisection of the brain stem was found to depend upon the presence of the anterior third of the corpus callosum. The opposite conjugate region of the cortex was not, however, essential. Evidence is presented which indicates that in each hemisphere the response is distributed to all parts of the cortex by a fiber system which originates in an area close to the temporal horn of the ventricle. Other known eortico-cortical association systems are apparently incapable of spreading the response. A type of spontaneous cortical rhythm is described which is dependent upon the same conducting system and not upon corticothalamic circuits.