The cerebrum, which is the largest part of the brain, is divided into two hemispheres--the left hemisphere and right hemisphere. Each hemisphere has all four lobes of the brain--frontal lobe, parietal lobe, temporal lobe and occipital lobe--but also has specialized functions. The two human brain hemispheres are connected by the corpus callosum, which allows for communication to be sent between the two halves.
Left Hemisphere
The left hemisphere of the brain controls the right side of the body. For example, the left hemisphere will send the information to the right arm in reaction to a sensation. The left hemisphere also receives information from the right eye: when an image is sent from the eye through the optic nerve, it crosses over at the optic chiasm and is sent to the opposite brain lobe. The University of Washington states that the left hemisphere contains the two language areas of the brain: Broca's area and Wernicke's area, which control the use and comprehension of language; the left hemisphere is also responsible for remembering information that was taken in through spoken or written language. Other specialized abilities of the left hemisphere are mathematics, logic and comprehending information.
Right Hemisphere
Like the left hemisphere, the right hemisphere controls the left side of the body and receives information from the left eye. The right hemisphere is responsible for more artistic abilities, such as music and art. The Centre for Neuro Skills notes that the right hemisphere gathers pieces of information and puts them together to form "the big picture." The right hemisphere is also involved in memory and learning, but focuses on information gathered from visual sources. Other specialized abilities of the right hemisphere are spacial abilities and face recognition.
Corpus Callosum
The University of Washington notes that the corpus callosum is made up of 200 million to 250 million nerve fibers and acts as the connection between the left hemisphere and the right hemisphere. When the corpus callosum is cut, such as during split brain surgery for epilepsy, the two hemispheres can no longer communicate; this results in each hemisphere acting as its own brain.
