The term paralimbic regions refers to two transition zones in the cerebral cortex of primates. Defined on the basis of internal structure, each zone consists of an inner band of periallocortex and an outer band of proisocortex. One, the insulo-orbito-temporopolar complex, provides the transition between the piriform cortex, which is paleocortex at the rostroventral end of the limbic lobe, and true isocortex of the insula, the orbital gyri and the temporopolar region. The other provides the transition between archicortex and true isocortex along the inner margin of the limbic lobe as it circles caudally, dorsally and rostrally over the corpus callosum ( Mesulam-1984 ).