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Hemisphere lateralization Popular psychology has suggested that the right brain is responsible for creativity and emotion, and the left brain is responsible for logic, analysis, and spatial reasoning. However, these are broad generalizations with little support. Both hemispheres process the same data. The difference is that the left brain processes in a linear, or sequential manner. The right brain processes data simultaneously, and because it is mute, does not connect plausible explanations immediately to each step in the process, but instead trusts the left brain to later link the reasoning behind beliefs or decisions. The best evidence of lateralization for one specific ability is language. Both of the major areas involved in language skills, Broca's area and Wernicke's area, are in the left hemisphere. Perceptual information from the eyes, ears, and rest of the body is sent to the opposite hemisphere, and motor information sent out to the body also comes from the opposite hemisphere (see also primary sensory areas). If these specific pieces of the brain are injured or destroyed, their functions can sometimes be recovered by neighboring brain regions - even opposite hemispheres. This depends more on the age the damage occurred than anything else. The magnocellular pathway of the visual system sends more information to the right hemisphere, while the parvocellular pathway sends more information to the left hemisphere. There are higher levels of the neurotransmitter norepinephrine on the right and higher levels of dopamine on the left. There is more white-matter (longer axons) on right and more grey-matter (cell bodies) on the left (Carter, 2004). Studying the brain has shown that simplistic pseudoscience claims about brain function tend to miss or skew vital information. It is important to stress that there is much about the brain that is not understood by scientists, but it is clear at this point that processes like creativity, emotion, spatial reasoning, and logical reasoning involve regions spread across the brain. Researchers neuropsychologists like Roger Sperry have studied split-brain patients to better understand lateralization. Sperry has also used tachistoscopes to present visual information to one hemisphere or the other. Scientists have also studied people born without a corpus callosum to determine specialization of brain hemispheres. The inflammation of the maninges is called meningitis. See also | ||||||||||
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