Event-related potential correlates of visuo-tactile motion processing in congenitally deaf humans.

The impact of congenital deafness on the development of vision has been investigated to a considerable degree. However, whether multisensory processing is affected by auditory deprivation has often remained largely overlooked. To fill this gap, we investigated the consequences of a profound auditory deprivation from birth on visuo-tactile processing. While the electroencephalogram (EEG) was recorded, dynamic visuo-tactile stimuli with a congruent or an incongruent motion direction were presented to a group of congenitally deaf native signers (N = 21) and matched hearing controls (N = 21). Standard stimuli were moving continuously for 200 ms either upwards or downwards, whereas the motion of deviant stimuli was interrupted in one of the two modalities. Participants were asked to detect deviant stimuli, moving in a predefined direction while ignoring deviants moving in the non-target direction. Behaviorally, deaf individuals committed more false alarms than hearing controls in the incongruent condition, that is, they responded more often when deviants moved in the non-target motion direction. ERPs (140-164 ms) of the deaf group were more anteriorly distributed for the visuo-tactile stimulation in comparison to hearing controls. Moreover, visuo-tactile motion congruency effects emerged with a later latency in the deaf group (350-450 ms) than in the hearing control group (200-280 ms). These findings suggest altered selection strategies and neural correlates for visuo-tactile motion processing as a result of congenital deafness.