Cerebral Cortex

About the Cerebral Cortex

The cerebral cortex is the thin outer layer of gray matter covering the cerebral hemispheres, only a few millimeters thick but highly folded into ridges called gyri and grooves called sulci, which greatly increases its surface area within the skull. Most of it is neocortex, organized into six layers of neurons. It is divided into frontal, parietal, temporal, and occipital lobes, each containing specialized areas: the primary motor cortex in the frontal lobe, the primary somatosensory cortex in the parietal lobe, the auditory cortex in the temporal lobe, and the visual cortex in the occipital lobe. Large association areas integrate information and support language, planning, decision making, and abstract thought. Early twentieth century work by Korbinian Brodmann divided the cortex into numbered areas based on cellular structure, a system still used today. Neurosurgeon Wilder Penfield mapped the body onto the motor and sensory cortex, producing the well known homunculus.