Question: In the Visual Ability test a split-brain patient was shown an image inthe left visual field but could not name the object. Explain why andidentify the specialized functions that were discovered with regard tohemispheric lateralization. Consider some of the difficulties thesplit-brain operation causes and the strategies you would recommend tohelp a patient manage them. Was it ethical to do this study? Was itright to trade the suffering experienced by participants for theknowledge gained by the research?
The split-brain is a condition that results after the communicationbetween the two hemispheres of the brain has been hindered. The primarypathway through which to transfer information in our brains is thecorpus callosum. Severing the corpus callosumis referred to as a callosotomy and is a last resort to treat severeforms of epilepsy. The right and left hemispheres of our brain arespecialized to carry out different tasks. The left hemisphere is ableto process one channel of information at a timebut is used to put things in sequence. This allows us to do thingssuch as use language. The right hemisphere on the other hand canprocess multiple channels simultaneously allowing us to do a number ofthings such as process visual information. Whenthese two sides cannot communicate a number of problems may result.Be sure to address all aspects of the assignment in your initial post.
Issues in Neuroscience
In the 1940s it was established that disconnecting the two hemisphere of cerebral through dividingcorpus callosum reduced the effects of epilepsy among theepileptic patients. This was because the sectioning of the nerve fibresbridge which connected the two hemispheres did not interfere with theinterhemispheric processing. However tests carriedout on patients who had been operated reveal that there are dramaticeffects brought about by the disconnection. This problem is known as thesplit-brain brain syndrome and has some effects on the patientscognitive skills.
Patients suffering from this syndrome are unable to verbally name anobject that is placed on their left hand side if their eyes are closed.This is despite the fact that they can tell an object placed on theirright when their eyes are closed. However if the object is placed amongmany items and placed on the patients left hand he or she can easilyselect the item from the other objects. Thisproblem is brought about by the fact that the left hemisphere hasaccess to speech something that the right hemisphere does not haveaccess to. This syndrome is caused by the fact the splitting of thebrain makes it unable to coordinate its activities. Theright hand part of the brain is unable to know what its left part isdoing whereas the left part is unable to know what the right hand partof the brain is doing (Plotnik & Kouyoumjian 2011).
To control this condition patients should pay a lot of attention towhat they do. This stems from the fact that the two parts of the braindo not coordinate in their operations which makes it hard for one partof the brain to understand what the other part is doing. In this casethrough paying attention the patient will be able to coordinate theactivities of both parts of the brain.
Doing this experience was ethically right if the identity of the personthe experiment was conducted on was not revealed. This is becausethe experiment was aimed to find out ways of helping the other patientssuffering from this problem and not for the benefit of the peopleconducting the experiment.
Plotnik R. & Kouyoumjian H. (2011).Introduction to psychology. Belmont CA: Wadsworth/Cengage Learning.
(an instructor response)
You provide useful information about the limitations of the split brainindividual. Could you talk more specifically about how you would assistthis person? Also aside from maintaining confidentiality are thereany other potential ethical issues?
First of all I hope you are doing better! I’m so sorry to hear that you have walking pneunomia. It can
be so tricky because you don’t think that your that sick until you go to the doctor and he orders
you to stay home from work for the next 3 weeks!
I really enjoyed reading your posting and wanted to ask you about your statement;
To control this condition the patient should pay attention towhat they do. This stems from the fact that the two parts of the braindo not coordinate in their operations which makes it hard for one partof the brain to understand what the other partis doing. In this case through paying attention the patient will beable to coordinate the activities of both parts of the brain.
Would you please explain what you meant by through paying attention.If a patient has a split-brain procedure and it is an acutedisconnection the patient is going to be struggling with many differenttypes of coordination;
When the corpus callosum of a right-handed left-hemispheredominate patient is sectioned there often follow mild akinesiaimperviousness and mutism as well as competitive movements between twohands. There are left-hand apraxia to verbal command left-armhypotonia well coordinated but repetitive reaching groping orgrasping with the left hand and
bilateral Babinski responses. Symptoms vary across patients and reflectedema from retraction (of one hemisphere to allow surgical approach) aswell as diaschistic shock to both hemispheres due to the radicaldisconnection. It is suggested by some that completecallosotomy (section of the corpus callosum alone) in cases wherespeech and manual dominance are in opposite hemispheres may result inprolonged loss of spontaneous speech (Bogen Zaidel & Zaidel 2014)
What would be your suggestion to the patient about how to best work withtheir new set of symptoms (post-op) so they can better understand howto achieve this control?
Please take good care of yourself!
BogenJ. Zaidel D. & Zaidel E.. (None Stated). The Split brain. InCaltech.edu. Retrieved 04/07/2014 fromhttp://www.its.caltech.edu/~jbogen/text/ref130.htm.