11 - Cross-modal plasticity in sensory systems

Summary

This chapter reviews studies of cross-modal interactions from two perspectives. One is the issue of crossmodal plasticity resulting from sensory deprivation, which is considered in terms of the twin questions: does deprivation of inputs in one sensory modality (1) improve perception in the remaining modalities? and (2) alter neural processing of the remaining inputs? With respect to this issue, plasticity of sensory-perceptual processing is distinguished from that of linguistic processing. Further, the effects of shortterm versus long-term sensory deprivation, and of the age of onset of deprivation are addressed, to the extent that they have been studied. A complementary perspective is offered by investigations of cross-modal involvement and multisensory processing in cortical regions that have traditionally been associated with a single sensory modality. The focus in this chapter is on studies of cross-modal interactions that affect the visual system. Similar interactions affecting the auditory system are reviewed in the previous chapter (this volume) by Rauschecker. The interested reader is referred to a review of the phenomena, neural correlates and possible mechanisms of cross-modal plasticity (Bavelier and Neville, 2002).

Superior non-visual perception in the blind

According to common belief, blindness is associated with superior non-visual perception. However, the empirical literature offers mixed support for this idea, despite over a century of investigation (Griesbach, 1899; Hollins, 1989).