Longitudinal fissure result from lesions to them. Diffusion tensor imaging (DTI or dMRI) along with fiber-tracking (FT) algorithms and functional Magnetic Resonance Imaging (fMRI) is used to image these bundles. For instance, occipital-callosal fiber tracts were localized with 1–2 mm precision using DTI-TF techniques - which are very important for the cooperation of visual cortices, and any lesion to them can lead to alexia, the inability to read. Longitudinal fissure The longitudinal fissure (or cerebral fissure, median longitudinal fissure, or interhemispheric fissure) is the deep groove that separates the two hemispheres of the vertebrate brain. The medial surfaces of the two hemispheres
Lateral sulcus point. The area lying around the Sylvian fissure is often referred to as the perisylvian cortex. 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