sperry study: split brains
hemisphere de-connection (split brains)
the brain is dived into two halves. the left and right hemispheres.for a right handed person, the left heisphere controls the right handside of the body and visa versa. for a left handed person this is also visa versa.it is not known why this crossover occurs.the two hemispheres are joined together by what is called commissural fibres, and the corpus collosum is by far the largest commissure (cross-hemisphere connection), responsible for carrying the information between the two hemispheres. the left hemispheres role is to be clever, rational and reasoning whereas the right heimsphere is purely spititual and artistic part.
lateralisation of function
lateralisation of function is the idea that different regions of the brain carry out different roles and specify in different tasks. damage to certain areas of the brain means that most likely you will no longer be able to do that task. for example language known as the broca's area is responsible for speech production and wernicke's area is responsible for speech comprehension.
much of the evidence has come from people who have damaged parts of their brain by for example cerebrovascular accidents. it occurs when an artery in the brain bursts or is obstructed, starving the neurones and tissue of oxygen, causing the brain cells to die. if a person has a stroke in the left hemisphere it will affect their right hand side of the body. this can be minor for example unable to move one side of their face. or major not being able to move an entire side of their body, known as hemiplegia. some patients who damage their broca area lose their speech as well as their right side of their body. this must be fustrating as they understand but cannot communicate with the people around them.
serving the connection
the two symmetrical hemispheres are only slightly different in the tasks they carry out.the two sides communicate via the corpus callosum. if this is damaged, than they can no longer communicate with each other.
there are rare instances of people having the connections between their two hemispheres severed, either as a result of an accident or, more likley, as one of the surgical treatments for epilepy. epileptic seizures are a result of abnormal electrical discharges of groups of brain neurones. the sourse of the problem is usually found in the temporal lobe and results in the person briefly losing contact with reality.sometimes the seizures can be more sustained, and these are known as grand mal seizures. the person goes unconcious and experiences muscle spasms, which may result in breaking bones and losing bowel and bladder control.
one surgical way of preventing seizures, especially in life threatening cases known as epilepticus, was to get a commissurotomy. which damages the corpus collosum so the two hemispheres can not communicate and therefore reducing the symptoms of seizures. this procedure prevented the discharges from spreading. you would think such a severe surgery would result in serious side effects…