Persisting Cross-Modal Changes in Sight-Recovery Individuals Modulate Visual Perception.

Recent neuroimaging studies have demonstrated that a brief period of congenital blindness induces long-lasting reorganization within the visual cortex of sight-recovery humans [1, 2]. However, the behavioral consequences of this cross-modal reorganization are not yet known. Here we investigated this question by examining the transfer of motion aftereffects across the visual and auditory modalities within six individuals who had been born blind due to dense bilateral cataracts and regained sight when they were treated at 5-24 months of age. Cataract-reversal individuals were compared to normally sighted participants and-to distinguish between the effects of early visual deprivation and residual visual impairments-to an additional group of individuals who had had pattern vision in childhood but later developed visual impairments. Cataract-reversal individuals-but not normally sighted or visually impaired participants-exhibited a significant visual motion aftereffect following adaptation to auditory motion. Despite this, cataract-reversal individuals were as likely as individuals in either control group to show a significant auditory motion aftereffect following adaptation to visual motion. These results extend previous findings of persisting cross-modal reorganization within the typically visual motion-selective area hMT+/V5 in sight-recovery individuals [3, 4], by providing the first demonstration that cross-modal adaptation to a brief phase of congenital blindness has behaviorally relevant consequences for visual perceptual recovery.