Injury- and use-related plasticity in the adult auditory system

After restricted cochlear lesions in adult animals, the frequency selectivi ty of neurons in the cortical region deprived of its normal input by the le sion is changed such that the region is occupied by expanded representation s of adjacent (perilesion) frequencies. Analogous changes in cortical frequ ency selectivity and organization are seen as a consequence of behavioral t raining that enhances the significance of particular acoustic stimuli. The occurrence of such reorganization in a wide range of species (including sim ian primates) suggests that it would also occur in humans. Direct evidence in support of this suggestion is provided by a small body of functional ima ging evidence. Although such reorganization almost certainly does not have a compensatory function, such a profound change in the pattern of cortical activation produced by stimuli exciting perilesion parts of the receptor ep ithelium would be expected to have perceptual consequences and, perhaps, cl inical implications. (C) 2000 by Elsevier Science Inc.