AUDITORY PROCESSING IN VISUAL BRAIN-AREAS OF THE EARLY BLIND - EVIDENCE FROM EVENT-RELATED POTENTIALS

Auditory event-related potentials (ERPs) were recorded in early blind subjects and sighted controls when they attended to stimuli delivered to a designated ear under dichotic conditions. The scalp distribution of the processing negativity (PN), the endogenous negativity elicited by attended stimuli, was in the blind posterior to that in the sighted . This suggests that posterior brain areas normally involved in vision participate in auditory selective attention in the early blind. Furth ermore, occasional higher-frequency tones in the to-be-ignored ear eli cited a negativity (presumably the mismatch negativity; MMN) that had a posterior scalp distribution in the blind as compared to controls. T his suggests that the posterior brain areas of the blind also particip ate in processing of auditory stimulus changes occurring outside the f ocus of attention.