 The human secondary somatosensory cortex (S2, SII) is a functionally-defined region of cortex in the parietal operculum on the ceiling of the lateral sulcus.The cerebral cortex was not depicted in a realistic manner until the 17th century with the Sylvian fissure being first accurately painted by Girolamo Fabrici d'Acquapendente in 1600 to provide plates for his "Tabulae Pictae".Its first description is traditionally taken to be in 1641 by Caspar Bartholin who attributed its discovery to Franciscus Sylvius (1614–1672), professor of medicine at Leiden University his book "Casp.