Human brain viewed from above, showing cerebral hemispheres. The front of the brain is to the right.
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:
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.
Ancient views of Left-Right hemisphere phenomena
Modern neuroscience is striving to a discovery that left-right hemisphere activity (cerebral breathing) & ultradian cycles were well known phenomena thousands years ago. Sources explain that human mood & activity directly depends on activity of left or right side of the brain or whole body.
Some sources even explain that this activity could or even should be controlled consciously. Rare people in the East Asia show extraordinary competences and abilities to control blood flow and nervous activity of right and left limbs.
Position of sleeping body is too important for & related to hemisphere activity or passivity. From old times there is widely known that right part of the body, brain or nose is related with Sun and left - with Moon.
Archaic sources do not speak about brain hemispheres separately, but of the "right and left" as whole mind-brain, mind-body phenomena.
Ancient hebrew sources explain that there are some specific phases of mastering of some left & right lines (kav smol & kav yamin). Important phase is conscious fixing of "right line" activity to extreme time - even 23,5 hours a day.
More: Kavim, Kav smol, Kav Yamin, Caduceus, Nadis, Nadi
- The Emerging Mind (http://www.bbc.co.uk/radio4/reith2003/lectures.shtml); Vilayanur S. Ramachandran; Reith Lectures 2003.
- Cerebral breathing - nasal ultradian cycles and hemisphere actitivy (http://home.gwi.net/~erichard/cerebr.htm)