Friday, 18 November 2011

Cognitive Neuropsycholgy - Blog 7 - Hemispheric Lateralisation

The human brain is split into two parts, which appear to work individually and have separate roles; these are the 'right' and 'left' hemispheres. These two hemispheres are connected by a thick layer of nerves called the corpus callosum. Research has consistently shown that the left hemisphere is predominantly involved in language and logic and the right hemisphere is predominantly involved in aspects of visuospatial ability and creativity (Martin, 2006). Although research indicates that the right and left hemisphere have exclusive roles it has been shown that this is not entirely true e.g. the right hemisphere has some language capabilities and the left hemisphere has some visuospatial abilities. Vogel, Bowers & Vogel, 2003 suggest that a person can have a dominant hemisphere meaning that if a person holds a creative personality they will have a dominant right hemisphere. Lateralisation’s to either hemisphere consequently carries great consequences and can alter a person’s social and mental skills. In order for doctors to help patients affected by these deficits, research needs to address whether hemispheres are exclusively used for specific abilities, however only brains that are brain damaged are testable as obviously it is unethical to carry out such invasive research on healthy humans therefore it is causes ambiguity to which particular parts of the brain control what activities in a normal healthy working brain.
.............................................. END..................................................

Extra notes;

  • Lesions in the left hemisphere affects language (aphasia).
  • It is suggested that the brain does not duplicate functions on both sides of the hemispheres, meaning that the two hemispheric sides are specalised for different functions.
  • The left hemisphere is more effective in language processing whereas the right hemisphere is more effective for visuospatial abilities.
  • The right hemisphere holds some linguistic ability but cannot perform phonological decoding.
  • In general the perceptual system first sees an object globally, it is reported that patients with a left-sided lesion are slow to identify local targets and that patients with right-sided lesions are slow to detect global targets.

No comments:

Post a Comment