Congenital blindness leads to enhanced vibrotactile perception
Previous studies have shown that in comparison with the sighted, blind individuals display superior non-visual perceptual abilities and differ in brain organisation. In this study, we investigated the performance of blind and sighted participants on a vibrotactile discrimination task. Thirty-three blind participants were classified into one of three groups (congenital, early, late), depending on the age at which they became blind. Consistent with previous neuroimaging data, individuals blinded after late childhood (14 years) showed no advantage over sighted participants. Both the congenitally- and early-blind participants were better than the sighted. The congenitally blind participants were even more accurate than the early-blind participants; a distinction that has not been drawn previously. Duration of blindness did not predict task performance and the effect of onset age persisted after duration of daily Braille reading was accounted for. We conclude that complete visual deprivation early in life leads to heightened tactile acuity.