Article

The aim of this review is to discuss the existing evidence supporting different
processes of visual brain plasticity after early damage, as opposed to damage
that occurs during adulthood. There is initial evidence that some of the
neuroplastic mechanisms adopted by the brain after early damage to the visual
system are unavailable at a later stage. These are, for example, the ability to
differentiate functional tissue within a larger dysplastic cortex during its
formation, or to develop new thalamo-cortical connections able to bypass the
lesion and reach their cortical destination in the occipital cortex. The young
brain also uses the same mechanisms available at later stages of development but
in a more efficient way. For example, in people with visual field defects of
central origin, the anatomical expansion of the extrastriatal visual network is
greater after an early lesion than after a later one, which results in more
efficient mechanisms of visual exploration of the blind field. A similar
mechanism is likely to support some of the differences found in people with
blindsight, the phenomenon of unconscious visual perception in the blind field.
In particular, compared with people with late lesions, those with early brain
damage appear to have stronger subjective awareness of stimuli hitting the blind
visual field, reported as a conscious feeling that something is present in the
visual field. Expanding our knowledge of these mechanisms could help the
development of early therapeutic interventions aimed at supporting and enhancing
visual reorganization at a time of greatest potential brain plasticity.
CI - (c) The Authors. Journal compilation (c) Mac Keith Press 2010.

Langue : ANGLAIS