origin of the myth
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The left/right brain myth likely arose from the Nobel Prize winning research of Roger Sperry in the 1960s. He operated on patients with epilepsy, separating direct communication between the two brain hemispheres by cutting a structure called the corpus callosum. This solved the epileptic seizures in many patients but resulted in dramatic changes where patients were not able to verbalise the answer in a memory test e.g. remembering that they had seen a picture of an apple, but they could pick up and physically select an apple from a number of items to show that they had remembered the correct answer - just that they couldn't say the word.
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evidence against the myth
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While we shouldn't continue to think of people or tasks as being 'right-brained' or 'left-brained', there is evidence for lateralised function in the brain e.g. in many people, speech and language tend to be processed in the left hemisphere in specialised regions such as Broca's area. However, this doesn't imply that great speakers and linguists use the left side of the brain more than the right or that there are more active neurons in one side or the other. Rather, in brain-scanning tasks, data reveal that both sides of the brain are required for many basic functions and that logical thinking or creativity are not more associated with the left or the right hemisphere but that both hemispheres work together rather than as separate entities.
Further references: 'Left brain, right brain: one brain, two brains'. Andrew Scull http://brain.oxfordjournals.org/content/133/10/3153 'Great Myths of the Brain' Christian Jarrett (2013) Wiley-Blackwell Press. |