title: The superiority in voice processing of the blind arises from neural plasticity at sensory processing stages.
abstract: Blind people rely much more on voices compared to sighted individuals when identifying other people. Previous research has suggested a faster processing of auditory input in blind individuals than sighted controls and an enhanced activation of temporal cortical regions during voice processing. The present study used event-related potentials (ERPs) to single out the sub-processes of auditory person identification that change and allow for superior voice processing after congenital blindness. A priming paradigm was employed in which two successive voices (S1 and S2) of either the same (50% of the trials) or different actors were presented. Congenitally blind and matched sighted participants made an old-young decision on the S2. During the pre-experimental familiarization with the stimuli, congenitally blind individuals showed faster learning rates than sighted controls. Reaction times were shorter in person-congruent trials than in person-incongruent trials in both groups. ERPs to S2 stimuli in person-incongruent as compared to person-congruent trials were significantly enhanced at early processing stages (100-160 ms) in congenitally blind participants only. A later negative ERP effect (>200 ms) was found in both groups. The scalp topographies of the experimental effects were characterized by a central and parietal distribution in the sighted but a more posterior distribution in the congenitally blind. These results provide evidence for an improvement of early voice processing stages and a reorganization of the person identification system as a neural correlate of compensatory behavioral improvements following congenital blindness.
authors.affiliation: Biological Psychology and Neuropsychology, University of Hamburg, 20146 Hamburg, Germany. jfoecker@bcs.rochester.edu
authors.forename: Julia
authors.initials: J
authors.lastname: Föcker
authors.forename: Anna
authors.initials: A
authors.lastname: Best
authors.forename: Cordula
authors.initials: C
authors.lastname: Hölig
authors.forename: Brigitte
authors.initials: B
authors.lastname: Röder
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001766:Blindness / Q000151:congenital*; D016022:Case-Control Studies; D004193:Discrimination Learning; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D011930:Reaction Time; D060865:Repetition Priming; D019987:Persons with Visual Disabilities; D014831:Voice