Neural plasticity of voice processing: Evidence from event-related potentials in late-onset blind and sighted individuals

Abstract

Purpose: Intra- and crossmodal neuroplasticity have been reported to underlie superior voice processing skills in congenitally blind individuals. The present study used event-related potentials (ERPs) in order to test if such compensatory plasticity is limited to the developing brain. Methods: Late blind individuals were compared to sighted controls in their ability to identify human voices. A priming paradigm was employed in which two successive voices (S1, S2) of the same (person-congruent) or different speakers (person-incongruent) were presented. Participants made an old-young decision on the S2. Results: In both groups ERPs to the auditory S2 were more negative in person-incongruent than in person-congruent trials between 200–300 ms. A topographic analysis suggested a more posteriorly shifted distribution of the Person Match effect (person-incongruent minus person-congruent trials) in late blind individuals compared to sighted controls. Conclusion: In contrast to congenitally blind individuals, late blind individuals did not show an early Person Match effect in the time range of the N1, suggesting that crossmodal compensation is mediated by later processing steps rather than by changes at early perceptual levels.