title: Visual Cross-Modal Re-Organization in Children with Cochlear Implants.
abstract: BACKGROUND
  Visual cross-modal re-organization is a neurophysiological process that occurs in deafness. The intact sensory modality of vision recruits cortical areas from the deprived sensory modality of audition. Such compensatory plasticity is documented in deaf adults and animals, and is related to deficits in speech perception performance in cochlear-implanted adults. However, it is unclear whether visual cross-modal re-organization takes place in cochlear-implanted children and whether it may be a source of variability contributing to speech and language outcomes. Thus, the aim of this study was to determine if visual cross-modal re-organization occurs in cochlear-implanted children, and whether it is related to deficits in speech perception performance.
  
  
  METHODS
  Visual evoked potentials (VEPs) were recorded via high-density EEG in 41 normal hearing children and 14 cochlear-implanted children, aged 5-15 years, in response to apparent motion and form change. Comparisons of VEP amplitude and latency, as well as source localization results, were conducted between the groups in order to view evidence of visual cross-modal re-organization. Finally, speech perception in background noise performance was correlated to the visual response in the implanted children.
  
  
  RESULTS
  Distinct VEP morphological patterns were observed in both the normal hearing and cochlear-implanted children. However, the cochlear-implanted children demonstrated larger VEP amplitudes and earlier latency, concurrent with activation of right temporal cortex including auditory regions, suggestive of visual cross-modal re-organization. The VEP N1 latency was negatively related to speech perception in background noise for children with cochlear implants.
  
  
  CONCLUSIONS
  Our results are among the first to describe cross modal re-organization of auditory cortex by the visual modality in deaf children fitted with cochlear implants. Our findings suggest that, as a group, children with cochlear implants show evidence of visual cross-modal recruitment, which may be a contributing source of variability in speech perception outcomes with their implant.
authors.affiliation: Brain and Behavior Laboratory, University of Colorado at Boulder, 409 UCB, 2501 Kittredge Loop Road, Boulder, Colorado, 80309, United States of America.|Institute of Cognitive Science, University of Colorado at Boulder, 344 UCB, Boulder, Colorado, 80309, United States of America.|Department of Speech, Language and Hearing Sciences, University of Colorado at Boulder, 409 UCB, 2501 Kittredge Loop Road, Boulder, Colorado, 80309, United States of America.
authors.forename: Julia
authors.initials: J
authors.lastname: Campbell
authors.affiliation: Brain and Behavior Laboratory, University of Colorado at Boulder, 409 UCB, 2501 Kittredge Loop Road, Boulder, Colorado, 80309, United States of America.|Institute of Cognitive Science, University of Colorado at Boulder, 344 UCB, Boulder, Colorado, 80309, United States of America.|Department of Speech, Language and Hearing Sciences, University of Colorado at Boulder, 409 UCB, 2501 Kittredge Loop Road, Boulder, Colorado, 80309, United States of America.
authors.forename: Anu
authors.initials: A
authors.lastname: Sharma
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D001303:Auditory Cortex / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D003054:Cochlear Implants; D003638:Deafness / Q000503:physiopathology* / Q000601:surgery; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D010775:Photic Stimulation; D013067:Speech Perception / Q000502:physiology; D014793:Visual Cortex / Q000503:physiopathology*; D014796:Visual Perception / Q000502:physiology*