Brain plasticity and preserved function in early blindness (on invitation by P. Pietrini and E. Ricciardi).

The “neural Darwinism” theory predicts that when one sensory modality is lacking, as in congenital blindness, the target structures are taken over by the afferent inputs from other senses that will promote and control their functional maturation (Edelman, 1993). This view receives support from functional brain imaging studies and behavioural experiments in early blind humans. Twenty years of research have shown that early visual deprivation leads to a crossmodal reorganization of the occipital cortex and an improvement of behavioral abilities. This crossmodal plasticity, however, maintains the function of part of the early visually deprived brain areas, which are presumably determined by experience-independent mechanisms but switch of sensory modality. A most exciting consequence is that sensory substitution in the blind may become a practical reality, allowing blind individuals to harness the power of crossmodal plasticity to perceive, localize and recognize objects with their auditory and tactile senses