Split-Brain - Essay Example

? Split-brain Split-brain Split-brain is a term used to describe the aftermath when the corpus callosum linking or connecting to the two hemispheres of the brain is damaged or severed to some extent. The corpus callosum is part of brain structure situated along the longitudinal fissures that carries out communication between the two hemispheres of the brain. It allows the connection between the left and right hemispheres of the brain. The split-brain patient’s two hemispheres are separated in that their left hemisphere does not recognize what the left hemisphere is doing. Each hemisphere functions differently since it is conscious of its own, and both the right and left hemispheres may be conscious simultaneously distinct even in mutually contradicting mental experiences. The operation that is carried out to produce this condition is known as corpus callosotomy. It is rarely applied to cure patients suffering from epilepsy (Sperry, 1968). The right and left hemispheres of the brain have distinct information processing strengths and capacities. These distinctions range from the kind of the perceptual knowledge that each hemisphere has and attends, to the well-recognized asymmetries for higher cognitive roles such as language. The most commonly known hemispheric memory is the general discrimination in the tendency to encode verbal information as objected to nonverbal information .Those patients with resection of anterior lobe have experienced verbal memory deficits that are in most cases pronounced after the left hemisphere than the right. On the other hand, severity to the corresponding areas in the right hemisphere has been linked with memory deficit for certain types of nonverbal information. The left hemisphere tend to include new verbal information into translated or interpreted representation while right hemisphere attends to and keep information about a person’s word stimuli. A person suffering from split-brain faces difficult moments in that when image of his or her left visual field is displayed, the person will not be in a position to name or state what they have seen. The most probable reason is that their speech control centre is aligned to the left side of the brain from the normal visual angle or field in majority of people. In addition, the image from the left side is sent to the right side of human brain; therefore, those people with speech control centre in their right hemisphere will experience same conditions when an image is presented to them in the right visual field. Communication between the two hemispheres is inhibited; the patient cannot be in a position to name what the right hemisphere of the brain is seeing. However, the person can recognize or pick up an object with their left hand not right hand since that hand on the other side of the body is controlled by right hemisphere of the brain. Similar effect takes place for reasoning and visual pairs. For instance, a patient suffering from split-brain condition is shown a picture of a snowy field and chicken in different visual fields and requested to choose from the list of words that best describes the pictures. The patient would end up foot to link it with chicken and shovel to link it with snow. When asked why he or she chose, shovel, the answer, or response will be related to the chicken such as shovel is used to clean up chicken coop (Sperry, 1968). The study found out that the two hemispheres are bonded by corpus callosum via which they connect, communicate and co-ordinate. Interaction between these two hemispheres is significant because they have distinct functions. The right side of the brain is responsible for spatial and nonverbal tasks while the left side is responsible for verbal roles such as writing and speaking. Sperry split brain has revealed the effects on the visual field on split-brain patients that there is redundancy or rudimentary gain in reaction period. Split-brain patients have shown that they react faster to bilateral stimuli than predicted or suggested model. The model that was proposed by Lacoboni states that patients with split brain meaning that every cerebral hemisphere or side has its own concentration system. This model suggested that redundancy gain in split-brain patients resulted due to slow response to unilateral stimuli rather than fast response to bilateral stimuli. The study revealed that following a stroke on the brain, role or functional deficiency of the brain is common. The deficiencies occur in areas that have been damaged. There were little functional plasticity recorded in beats or partial callosotomies but much of plasticity can be observed in children patient getting hemispherctomy, which indicates that the opposite hemisphere can cope up with some functions that were initially performed by its opposite hemisphere. Memory of the split-brain patient tends to be lower than normal though better than in patients suffering from amnesia indicating that the brain is responsible for formation of some types of memory. It showed that posterior callosal which incorporates hippocampal commisures leads to mild memory loss. Split-brain patients act in a purposeful, consistent, and coordinated way despite parallel and different contradicting processing of similar information from the environment by two different hemispheres that are disconnected. When the right and let hemisphere receives two conflicting and competing information at the same time, the responses tends to determine which hemisphere controls the behavior. Split-brain patients usually have mechanism to compensate their interhemispheric transfer deficits by acquiring variety of strategies to adapt to the situation (Sperry, 1968). The right hemisphere is significant when a person is giving direction or map on how to get from bus station to the shopping mall. It was noticed that the right hemisphere was possible in producing rudimentary phrases and words but also contributes to emotional context to language. For instance, without the assistance from the right side of the brain, one would be in a position to read the word monkey but would not imagine what it is. The study had its weakness in that it dwelt so much on simplistic summaries about specialization functions. In addition, the people who were used in the study were people who had suffered from epilepsy for some years. Finally, the sample used was too small and locked out or did not include children in the study. The study realized that the two hemispheres have different or separate function. The brain is composed of independent agents or aspects and they have the ability to carry out activities outside our conscious awareness, which is believed to be in the left hemisphere. Reference R W Sperry, Hemisphere deconnection and unity in consciousness. American Psychologist, Kindle Books, New York, 1968 pp. 723-33. Read More