Hemispheric specialisation in
normal and disturbed development
Several studies were performed to search
for the mechanisms and principles underlying the functional capacities of
the two hemispheres. The studies performed both on patients with brain
lesions and normal subjects showed that a variety of functions (e. g.
perception of faces, stereoscopic depth, spatial frequency, visual
illusion, tilt effects and other visual-spatial patterns) is mediated
primarily by the right hemisphere. Moreover, they provided evidence that
hemispheric differences may emerge at relatively early stage of
processing. This changed the widely accepted view, which attributed the
functional brain asymmetry to processes that occur at a higher cognitive
level. Our data pointed to the importance of callosal communication. The
accumulated data allowed to formulate a new dynamic model in which
hemispheric specialisation is conceptualised as a complex system of
different asymmetrically represented modules tied by callosal pathways
that serve to integrate the operations carried out by those modules The
research concerned also a controversial issue of the relationship between
handedness and cerebral organisation. We have found that this
relationship is modified by the sex factor.
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