The part of the cerebral cortex of the vertebrate brain that has evolved most recently, and is most highly developed in mammals. In humans and other primates it forms a surface layer covering most of the forebrain and comprises six layers of neurons with a multitude of interconnections; it is greatly folded to vastly increase its surface area. The expansion of the neocortex in primates is thought to be correlated with their complex social behaviour. It is the major centre for the coordination of sensory and motor information. See cerebrum.