The neocortex is a part of the brain of mammals.
It is the top layer of the cerebral hemispheres, 2-4 mm thick, and made up of six layers, labelled I to VI (with VI being the innermost and I being the outermost).
The neocortex is part of the cerebral cortex (along with the archicortex and paleocortex - which are cortical parts of the limbic system).
It is involved in higher functions such as sensory perception, generation of motor commands, spatial reasoning, conscious thought, and in humans, language.
The neocortex consists of grey matter surrounding the deeper white matter of the cerebrum.
While the neocortex is smooth in rats and some other small mammals, it has deep grooves (sulci) and wrinkles (gyri) in primates and several other mammals.
These folds serve to increase the area of the neocortex considerably.
In humans it accounts for about 76% of the brain's volume.