The term area SI of Woolsey refers to a functionally defined area of mammalian cerebral cortex. It has been mapped in a number of species on the basis of evoked potentials elicited by light touch stimulation of the skin. In the macaque it is located in the postcentral gyrus, both on the exposed surface and in the posterior bank of the central sulcus. The face area is located on the lower lateral surface with the hind limb and tail areas extending over the midline into the bank of the longitudinal fissure ( Woolsey-1958 ). It is the same as the primary somatosensory cortex ( Carpenter-1983 ).