Abstract

SEPULVEDA-PALOMO, Marta. Differences in the primary visual cortex between congenital, early and late blindness. A systematic review. Rev Ecuat Neurol [online]. 2021, vol.30, n.1, pp.145-153. ISSN 2631-2581.  https://doi.org/10.46997/revecuatneurol30100145.

The loss of a sense, such as sight, promotes research on brain plasticity and the activity of the visual cortex, either with task or at resting-state. However, the activity of the primary visual area, its role in perception through cortical signals, once blindness has developed, is still being investigated. There is evidence of the differences between the changes associated with the different types of blindness, however, it is difficult to define how the anatomical and functional changes are interrelated and how they depend on, when vision is lost. That is why the main objective of this review is the clarification and definition of said modifications.

Important differences have been found in terms of the thickness and volume of the visual area, and how its decrease implies a greater activity detected by overload of neurons. Therefore, it explains a greater activity in congenital and early blindness compared to late blindness. Similarly, there is greater connectivity between the ventral and dorsal pathways in congenital blindness, as well as a lesser decrease in fractional anisotropy of the white matter (FA), compared to the other two types of blindness.

Keywords : Congenitally blind; late blind; primary visual area; RM; resting-state; V1..

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