The Implications of Brain Plasticity and Task Selectivity for Visual Rehabilitation of Blind and Visually Impaired Individuals

The human brain is a formidably complex and adaptable organ capable of rewiring itself or adjusting existing connections in order to learn and to maximize its survival edge. Studies using sensory substitution devices have had a big impact on the uncovering of the mechanisms subtending brain organization. Sensory substitution devices are capable of conveying information typically received through a specific sensory modality (e.g., vision) and transferring it to the user via a different sense (e.g., audition or touch). Experimental research exploring the perceptual learning of sensory substitution devices has revealed the ability of users to recognize movement and shapes, to navigate routes, to detect and avoid obstacles, and to perceive colors or depth via touch or sound, even in cases of full and congenital blindness. Using a combination of functional and anatomical neuroimaging techniques, the comparisons of performances between congenitally blind people and sighted people using sensory substitution devices in perceptual and sensory-motor tasks as well as in several recognition tasks uncovered the striking ability of the brain to rewire itself during perceptual learning and to learn to interpret novel sensory information even during adulthood. This review discusses the impact of invasive and noninvasive forms of artificial vision on brain organization with a special emphasis on sensory substitution devices and also discusses the implications of these findings for the visual rehabilitation of congenitally and late blind and partially sighted individuals while applying insights from neuroimaging and psychophysics.