Visually challenged individuals often compensate for their handicap by developing supra-normal abilities in their remaining sensory systems. Here, we examined the scalp distribution of components N1 and P3 of auditory evoked potentials during a sound localization task in four totally blind subjects who had previously shown better performance than sighted subjects. Both N1 and P3 waves peaked at their usual positions while blind and sighted individuals performed the task. However, in blind subjects these two components were also found to be robust over occipital regions while in sighted individuals this pattern was not seen. We conclude that deafferented posterior visual areas in blind individuals are recruited to carry out auditory functions, enabling these individuals to compensate for their lack of vision.
1Groupe de Recherche en Neuropsychologie Expérimentale, Département de Psychologie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7
2Institut Universitaire de Gériatrie de Montréal, Canada
3Corresponding Author: Franco Lepore
Acknowledgements: We thank the Regroupement pour les Aveugles et Amblyopes de Montréal (RAAM) for their cooperation to this study, and Nadia Lessard and Michel Pare for their assistance in recruiting participants. This work was supported by grants from NSERC, FCAR and FRSQ-FCAR-Santé.
Received 21 October; accepted 9 December 1999