The cerebral hemisphere
is one half of a brain
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
. This is divided into four lobes: the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe.
The left hemisphere of the human brain is specialised for speech, writing, language and calculation. The right hemisphere is specialised for spatial abilities, visual face recognition and some aspects of music perception and production.
The hemispheres are linked by the corpus callosum, a large bundle of nerve fibers.