Topic: Brain Function —— Split Brain Patients
- Concept Description:
Our brain are divided into left hemisphere and right hemisphere. They work together to help people living, doing works, speaking, and so on. The concept is that left hemisphere is responsible for logical issues like languages, analysis, classification, and right hemisphere is responsible for emotional issues like art, music, recognition of face and shapes. Also, left brain controls right side of body and right brain controls left side of body. The two parts of brain are connected by corpus callosum, so they work together through the help of it.
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- Real World Experiences:
In order to make clear the corresponding function of different parts of the brain, people did an Split Brain Experiment, which is to conduct the consequences of functions from brain without corpus callosum. Here I want to notice that it is illegal to use alive people to do the experiment so the scientists did not really cut the corpus callosum. They use volunteers who had already had problems with their brain. For example, people who has injured with epilepsy need to be cured by cutting their corpus callosum.
Roger Sperry in 1981 did an experiment with split brain patients. In daily life, the patient seemed usual. He could walk, speak, write, hold things, and so on. The patient was presented with a row of horizontal lights flashed across the visual field. The patient was only able to say out when the lights flashed on the right side, not the left side. Surprisingly, when asking the patient to point at the lights when they flashed, rather than spoke it out, the patient could also accurately identify all the lights.
Sperry did another experiment to test the right hemisphere. The patient placed their left hand in a box but cannot see the objects. Then a picture of one of the subject in the box was shown to the patient’s left visual field. The patient’s left hand picked up the object corresponding to the picture. However, the patient claimed that he had no idea why holding the object.
- How the experience and concept related
In the first experiment, the patient could only see the lights on the right side means that only the left hemisphere works to see something. However, he cannot report lights appeared on the left side of the view means that right hemisphere do not have language ability. While both brain hemispheres are capable of perceiving the lights, only the left hemisphere is capable of translating this knowledge into speech. Therefore we can say that the left hemisphere controls language and speech.
In the second example, the picture was shown in the left visual field, so the right brain had recognized the word and told the left hand to pick it up. However, because the right side of the brain do not have language ability and the left side of the brain cannot see the picture, the patient could not explain why they picked up the corresponding object. Therefore, we can say that the right hemisphere controls recognition of shapes.
- References
Bryan, N. (2015). “What were the split brain experiments?” [Online]. Available from: https://www.mnn.com/health/fitness-well-being/stories/what-were-the-split-brain-experiments [Accessed 16 September 2019]
Lienhard, Dina A., “Roger Sperry’s Split Brain Experiments (1959–1968)”. Embryo Project Encyclopedia (2017-12-27). [Online]. Available from: https://embryo.asu.edu/pages/roger-sperrys-split-brain-experiments-1959-1968 [Accessed 16 September 2019]
MLA style: “The Split Brain Experiments”. Nobelprize.org. Nobel Media AB 2014. [Online]. Abailable from: https://educationalgames.nobelprize.org/educational/medicine/split-brain/background.html [Accessed 16 September 2019]
l Appendix
There is a link of a video for the split brain experiment:
https://www.youtube.com/watch?v=ZMLzP1VCANo