Localization of Functions

in the cerebral cortex, the representation of various functions in the cerebral cortex.

The earliest data on the localization of functions in the cerebral cortex were obtained by electrical stimulation of and surgical intervention in the cortex; investigation of the formation mechanism of conditioned reflexes, in combination with the temporary exclusion or removal of the respective parts of the cortex; and analysis of electroencephalographic data. The anterior central gyrus of the cortex is regarded as the principal motor zone; the posterior central gyrus, as the sensory zone. The auditory, visual, vestibular, and olfactory zones are located beyond the sensorimotor cortex and occupy a greater area than the zone in which cutaneomuscular sensitivity and viscera are represented: the auditory zone in man is located in the region of the superior temporal gyrus; the visual, in the occipital region (mainly around the sulcus calcarinus); the olfactory, in the region of the hippocampal gyrus; and speech, in the left hemisphere.