Altered tactile spatial attention in the early blind

To investigate whether superior tactile acuity in the blind is due to alterations of attentional selection mechanisms, event-related brain potentials (ERPs) were measured in a group of early blind and a group of sighted individuals who performed a difficult tactile spatial selection task. We found systematic differences in the attentional processing of tactile events between early blind and sighted individuals. The blind not only responded faster to tactile targets, but also showed attentional modulations of early somatosensory ERP components (P100 and N140). In contrast, ERP effects of spatial attention in the sighted only emerged at longer-latencies (about 200 ms post-stimulus). Our findings suggest that increased use of one sense due to sensory deprivation, such as touch in blind people, leads to alterations of attentional selection mechanism within modality-specific cortex.