Physiologically; the right side of the brain deals with neurological impulse for the left side of the body and the inverse is true. In his “split-brain” research on an epileptic patient, Roger Sperry (1973) (cited in Dan Eden, n.d) demonstrated that with the severing of their communication connection the two hemispheres could function distinctively.
For instance the right eye and hand could name an item, like a pen, but the subject could not determine its use. On the other hand the left eye and hand could demonstrate and determine its use but could not determine its name.
In his further studies to establish the functional map of the brain, Sperry (1973) (cited in Eden, n.d) supposes the existence of two nature of thought, namely the verbal and the non-verbal, which have their basis in the left and the right brain hemispheres respectively. The chart below illustrates the function mapping of the hemisphere (Eden, n.d).
The two Hemispheres functional integration
Personality can be thought of as the product of the extent to which hemispheres associate or dissociate. For instant, criticality and orderliness is an attributed of the left hemisphere; while the artistic, creativity and unpredictability is that of the right.
However, every individual integrates particular sides of the brain in their various daily activities based on factors such as education, age and experiences. Thus, the involvement of a specific hemisphere in different circumstances determines our character and molds our personality (Eden, 2008).
Studies have established that majority of the children creativity rank high (right hemispheres attribute) prior to schooling. However, only 10% of the children would retain their creativity by the age of seven, since the current educational system emphasizes on the left brain characteristics like mathematics, language and logic than on creativity (Eden, 2008).
Despite their function lateralization, the hemispheres do not perform independently, but communicate via the corpus callosum. Nevertheless, this association does not operate on equality basis because one hemisphere usually dominates over the other. Thus, individuals can either be left or right handed. Normally, the left hemisphere is considered the dominant hemisphere (Ball, 1998).
Implications for the cognitive research neuroscientist
Owing to the obstacles of direct methods in neurological studies of a particular behavior, neurological scientists have render use of indirect methods, such as handedness technique to establish the dominant hemisphere. However, the understanding of how this methods work poses a challenge to many research neuroscientists, in which practical and theoretical implications are, attached (Ball, 1998).
However, distinction are not absolute, thereby necessitating verification of a patients’ match to the right or left hemisphere profile before a brain surgeons excise an area of an epileptic brain to avoid causing major impairments. To achieve this objective, many methods have been developed to allow the evaluation of activities of the two hemispheres in life subjects (Ball, 1998).
The first technique was known as the Wada test, coined after a neurologist name Juhn Wada. It involves the injection of sodium amorbarbital into either the left or right carotid artery. Consequently, the hemisphere which corresponds to the injection becomes numb, allowing the doctor to carry out language test on the conscious hemisphere (Ball, 1998).
These and other techniques developed for this purpose are expensive and dangerous. Easier methods of evaluating lateralization must be opted for. Thus handedness method has been opted for by many neuroscientists in their approach to the relevant psychological issue. The essence for this choice is the fact that right-handedness implies that the left hemisphere dominates and vice versa. Apparently, this technique has proven to be the most convenient method of determining the dominant hemisphere (Ball, 1998).
Reference List
Ball, J. (1998). Lateralization of function in cerebral hemispheres. Serendip; biology 202. Retrieved from https://serendipstudio.org/exchange/node/1782
Eden, D. (2008). Left brain; Right brain. Retrieved from http://viewzone2.com/bicamx.html