Cerebral hemisphere
From open-encyclopedia.com - the free encyclopedia.
The cerebral hemisphere forms one half of a brain. Humans (and many other types of animals) have a brain divided into two hemispheres. Each hemisphere is a mirror image of the other and has an outer layer of gray matter called the cerebral cortex.
Neurologists normally subdivide the cerebral cortex into the following four lobes:
- the frontal lobe - in front of the parietal lobe
- the parietal lobe - above the occipital lobe, behind the frontal lobe
- the occipital lobe - in the rearmost portion of the skull
- the temporal lobe - at the side of the skull
Neurologists also recognize two additional areas of the cerebral cortex:
- the Limbic Cortex - including the cingulate cortex, located above the corpus callosum.
- the Insular Cortex - buried within the lateral sulcus.
In most people, the left hemisphere of the human brain dominates, and specialises (in very broad terms) in speech, writing, language and calculation. The right hemisphere has equivalent broad associations with spatial abilities, coherent form recognition, visual face recognition and some aspects of music perception and production. (Pop psychology simplifies these distinctions into a crude binary system whereby a person appears pre-dominantly "left-brained" or "right-brained": logical or "creative"; or vice versa. One or the other.)
The hemispheres operate together, linked by the corpus callosum, a very large bundle of nerve fibers, and also by other smaller commissures, including the anterior commissure.
