neocortex

n. Newer portion of the cortex found in the brain of mammals. It is about 2–5 mm thick and contains some 100 billon cells. The distinctive characteristic of neocortex (also known as neopallium or isocortex) is that it is composed by six different layers (numbered from I to VI). The neocortex is the type of cerebral cortex most recent in evolution. Archicortex and paleocortex (both referred as allocortex) are phylogenetically older and contain a lower number of layers. The neocortex contains the body of the neurons (gray matter). With evolution, the sulci (grooves) and gyri (wrinkles) increase, increasing the total area of the neocortex. It is assumed that the neocortex is crucial in complex forms of cognition, such as language, complex perception, and reasoning. – AA