Affiliations: Department of Speech, Language, and Hearing Science,
University of Colorado at Boulder, Boulder, CO, USA | Eunice Kennedy Shriver Center, University of
Massachusetts Medical School, Waltham, MA, USA | Department of Speech and Hearing Science, Arizona
State University, Tempe, AZ, USA
Note: [] Corresponding author: Phillip M. Gilley, Ph.D., The University
of Colorado at Boulder, Department of Speech, Language, and Hearing Sciences,
2501 Kittredge Loop Rd., 409 UCB, Boulder, CO 80309-0409, USA. Tel.: +1 303 492
5096; Fax: +1 303 492 3274; E-mail: [email protected]
Abstract: Purpose: Children who experience long periods of auditory
deprivation are susceptible to large-scale reorganization of auditory cortical
areas responsible for the perception of speech and language. One consequence of
this reorganization is that integration of combined auditory and visual
information may be altered after hearing is restored with a cochlear implant.
Our goal was to investigate the effects of reorganization in a task that
examines performance during multisensory integration. Methods: Reaction
times to the detection of basic auditory (A), visual (V), and combined
auditory-visual (AV) stimuli were examined in a group of normally hearing
children, and in two groups of cochlear implanted children: (1) early implanted
children in whom cortical auditory evoked potentials (CAEPs) fell within normal
developmental limits, and (2) late implanted children in whom CAEPs were
outside of normal developmental limits. Miller's test of the race model
inequality was performed for each group in order to examine the effects of
auditory deprivation on multisensory integration abilities after implantation. Results: Results revealed a significant violation of the race model
inequality in the normally hearing and early implanted children, but not in the
group of late implanted children. Conclusion: These results suggest that
coactivation to multi-modal sensory input cannot explain the decreased reaction
times to multi-modal input in late implanted children. These results are
discussed in regards to current models for coactivation to redundant sensory
information.
Keywords: Multisensory integration, cochlear implants, redundant signal effect (RSE), race model inequality
