Audio-tactile integration in congenitally and late deaf cochlear implant users.

Elena Nava,Davide Bottari,Ineke Fengler,Brigitte Röder,Agnes Villwock,Andreas Büchner,Thomas Lenarz,Maurice Ptito

doi:10.1371/journal.pone.0099606

Abstract

Several studies conducted in mammals and humans have shown that multisensory processing may be impaired following congenital sensory loss and in particular if no experience is achieved within specific early developmental time windows known as sensitive periods. In this study we investigated whether basic multisensory abilities are impaired in hearing-restored individuals with deafness acquired at different stages of development. To this aim, we tested congenitally and late deaf cochlear implant (CI) recipients, age-matched with two groups of hearing controls, on an audio-tactile redundancy paradigm, in which reaction times to unimodal and crossmodal redundant signals were measured. Our results showed that both congenitally and late deaf CI recipients were able to integrate audio-tactile stimuli, suggesting that congenital and acquired deafness does not prevent the development and recovery of basic multisensory processing. However, we found that congenitally deaf CI recipients had a lower multisensory gain compared to their matched controls, which may be explained by their faster responses to tactile stimuli. We discuss this finding in the context of reorganisation of the sensory systems following sensory loss and the possibility that these changes cannot be “rewired” through auditory reafferentation.

Highlights

Neurophysiological studies conducted in mammals have shown that multisensory neurons and the ability to integrate crossmodal information require an extensive time of sensory experience during early development in order to fully mature [1,2]
The present study examined whether congenitally and late deaf cochlear implant (CI) recipients are able to integrate simple audio-tactile stimuli as measured in a redundant target paradigm
We found reliable redundancy gains for audio-tactile stimuli compared to unimodal stimuli and a violation of the race model for both congenitally and late deaf CI recipients

Summary

Introduction

Neurophysiological studies conducted in mammals have shown that multisensory neurons and the ability to integrate crossmodal information require an extensive time of sensory experience during early development in order to fully mature [1,2]. This predicts that sensory deprivation may impair multisensory processing, as has been extensively documented in visually deprived animals [3,4] and in blind humans too [5,8]. Older infants did not show any looking preference, suggesting the inability to match non-native faces and calls

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Results

Conclusion