Neuroplasticity in visual impairments

Abstract

The visual acuity loss enables the brain to access new pathways in the quest to overcome the visual limitation and this is wellknown as neuroplasticity which have mechanisms to cortical reorganization. In this review, we related the evidences about the neuroplasticity as well as cortical anatomical differences and functional repercussions in visual impairments. We performed a systematic review of PUBMED database, without date or status publication restrictions. The findings demonstrate that the visual impairment produce a compensatory sensorial effect, in which non-visual areas are related to both cross (visual congenital) and multimodal (late blind) neuroplasticity.

Keywords: Neuroplasticity; central nervous system; vision; visual impairments.

Figure 1.

(A) Schematic representation of areas related to vision in healthy individuals. (B) Schematic representation of areas involved in language comprehension and semantic processes. (C) Representation of cross-neuroplasticity in congenital visually impaired patients. It is observed, an expansion of areas not related to vision to the visual cortex resulting in an improvement of non-visual senses.

Figure 2.

Schematic diagram showing multimodal neuroplasticity. (A) In people with normal vision, the occipital cortex receives and processes visual information by inhibiting preexisting pathways for non-visual functions such as hearing, touch, and smell. (B) In early visual impaired, the absence of visual information processing promotes an activation of pathways that were previously inhibited by vision resulting in improved hearing, touch, and smell.

Figure 3.

The illustration shows that cross-plasticity phenomena can be regulated over a sensitive period, in which sensory experience has a greater influence on behavioral and cortical development.