Neocortex

The neocortex (literally translated "new coat or layer") is the six-layered outer layer of the mammalian brain. It consists of vertically organised cortical columns as discovered and described by Vernon Mountcastle. In higher mammals and primates such as humans the neocortex has adapted a highly folded structure, with bumps (gyri) and valleys (sulci) making up the typical surface appearance of the cortex. This structure of columns is preserved all across the surface of the cortex and it is now believed that only the connectivity patterns and cell density distinguish the function of one area of cortex from another. This is why the cortical macrocolumn, which consists of about 60.000 neurons and about a thousand minicolumns in the human cortex, is considered to be the basic 'computing' unit of the neocortex. The neocortex is considered to be the seat of intelligence, all higher brain functions such as thought, perception, consciousness, memory, problem solving, creativity etc. are all considered to be functions of the common algorithm on which the neocortex operates. it consists of a large number of tightly packed neurons with their dendrites and axons and sitting atop a large amount of long distance axons covered with myelin that connect the different areas of the neocortex and connects it to the various older parts of the brain. The first type of tissue is called the grey matter and the 'box of cables' below it is called the white matter. It is believed that the neocortex is organised in a hierarchial structure ie. sensory input comes in and goes through a hierarchy of cortical areas and the higher up the hierarchy you go, the more abstract the representations of the cortex become.

Organisation of the cortex

The cortex consists of six layers, differentiated by the celltypes and connectivity patterns that occur within them.