Article

Journal of Neurodevelopmental Disorders

, Volume 3, Issue 4, pp 388-404

Open Access This content is freely available online to anyone, anywhere at any time.

Language development after cochlear implantation: an epigenetic model

  • Timothy M. MarkmanAffiliated withJohns Hopkins School of Medicine
  • , Alexandra L. QuittnerAffiliated withUniversity of Miami
  • , Laurie S. EisenbergAffiliated withHouse Ear Institute
  • , Emily A. TobeyAffiliated withUniversity of Texas at Dallas
  • , Donna ThalAffiliated withSan Diego State UniversityCenter for Research on Language, University of California
  • , John K. NiparkoAffiliated withDepartment of Otolaryngology-Head and Neck Surgery, The Johns Hopkins School of Medicine Email author 
  • , Nae-Yuh WangAffiliated withDepartment of Medicine, Johns Hopkins School of MedicineDepartment of Biostatistics, Johns Hopkins Bloomberg School of Public Health
  • , The CDaCI Investigative Team

Abstract

Growing evidence supports the notion that dynamic gene expression, subject to epigenetic control, organizes multiple influences to enable a child to learn to listen and to talk. Here, we review neurobiological and genetic influences on spoken language development in the context of results of a longitudinal trial of cochlear implantation of young children with severe to profound sensorineural hearing loss in the Childhood Development after Cochlear Implantation study. We specifically examine the results of cochlear implantation in participants who were congenitally deaf (N = 116). Prior to intervention, these participants were subject to naturally imposed constraints in sensory (acoustic–phonologic) inputs during critical phases of development when spoken language skills are typically achieved rapidly. Their candidacy for a cochlear implant was prompted by delays (n = 20) or an essential absence of spoken language acquisition (n = 96). Observations thus present an opportunity to evaluate the impact of factors that influence the emergence of spoken language, particularly in the context of hearing restoration in sensitive periods for language acquisition. Outcomes demonstrate considerable variation in spoken language learning, although significant advantages exist for the congenitally deaf children implanted prior to 18 months of age. While age at implantation carries high predictive value in forecasting performance on measures of spoken language, several factors show significant association, particularly those related to parent–child interactions. Importantly, the significance of environmental variables in their predictive value for language development varies with age at implantation. These observations are considered in the context of an epigenetic model in which dynamic genomic expression can modulate aspects of auditory learning, offering insights into factors that can influence a child’s acquisition of spoken language after cochlear implantation. Increased understanding of these interactions could lead to targeted interventions that interact with the epigenome to influence language outcomes with intervention, particularly in periods in which development is subject to time-sensitive experience.

Keywords

Epigenetics Spoken language Cochlear implant results