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Split-Brain Functioning

Current Status

Much research is being carried out to assess the roles of genetic and environmental factors in the development of hemispheric asymmetry. Because of the difficulty or impossibility in manipulating either of these factors, and or in designing studies that can accurately separate their influence, there are no firm conclusions at this time. It seems safe to say that environmental and genetic factors interact to determine the division of functions between the hemispheres.

It has become clear that the two hemispheres differ in their capabilities and organization, yet it is still the case that in the normal brain the two hemispheres work together in a coordinated manner, and both hemispheres play a role in almost all behaviors. Indeed, the differences in functioning between the hemispheres that have been found seem to complement one another. Research on how the two hemispheres differ and interact continues unabated, and improvements in technologies used to measure the brain as well as accumulating knowledge promise increasing gains in our knowledge of the human brain.

Resources

Books

Boller, F., and J. Grafman (series eds.) and I. Raping and S. Segalowitz (vol. eds.). Handbook of Neuropsychology. Vols 1-6. New York: Elvesier, 1988-92.

Springer, S.P., and G. Deutsch. Left Brain, Right Brain. 3rd ed. New York: W.H. Freeman and Company, 1989.


Marie Doorey

KEY TERMS


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Aphasia

—A general term describing any partial or complete loss of linguistic abilities that is caused by a lesion in the brain.

Brain-imaging techniques

—High technology techniques allowing non-intrusive visualization of the brain, these include computed tomography, positron emission tomography, and functional magnetic resonance imaging.

Cerebrum

—The upper, main part of the human brain, it is made up of the two hemispheres, and is the most recent brain structure to have evolved. It is involved in higher cognitive functions such as reasoning, language, and planning.

Corpus callosum

—The most prominent mass of nerve fibers connecting the two cerebral hemispheres of the brain; it aids in the transfer of information between them.

Hemispheres

—The two halves of the cerebrum, the largest and most prominent structure of the brain, which are connected by a number of nerve fiber masses.

Laterality

—Used generally to describe the asymmetry of the brain hemispheres in particular cognitive functions.

Lesion

—Used commonly to describe a limited area of damage to living tissue matter caused by surgical intervention, disease, or injury.

Parietal lobes

—Regions of the cerebral hemispheres that are above the temporal lobes and between the frontal and occipital lobes.

Split-brain surgery

—A technique in which the corpus callosum is severed; it is used to stop the spread of seizure activity between the hemispheres in those with severe epilepsy. Research on cerebral asymmetry with split-brain patients has yielded a considerable amount of information.

Temporal lobe

—The lobe of the cerebrum that is in front of the occipital lobe and below the lateral fissure.

Temporal plane

—An area of the brain lying in a region called Wernicke's area, so-called because Wernicke observed that injuries in this region often lead to aphasic symptoms.

Additional topics

Science EncyclopediaScience & Philosophy: Spectroscopy to Stoma (pl. stomata)Split-Brain Functioning - History, Basic Anatomy And Brain Functioning, Methods Of Study, Anatomical Asymmetries, Handedness, Functional Asymmetries