, Volume 3, Issue 4, pp 388-404,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 19 Nov 2011

Language development after cochlear implantation: an epigenetic model

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.

CDaCI Investigative Team Members
House Research Institute, Los Angeles, CA: Laurie S. Eisenberg, PhD, CCC-A (principal investigator); Karen Johnson, PhD, CCC-A (coordinator); William Luxford, MD (surgeon); Leslie Visser-Dumont, MA, CCC-A (data collection); Amy Martinez, MA, CCC-A (data collection); Dianne Hammes Ganguly, MA (data collection); Jennifer Still, MHS (data collection); and Carren J. Stika, PhD (data collection).
Johns Hopkins University, Listening Center, Baltimore, MD: John K. Niparko, MD (principal investigator); Steve Bowditch, MS, CCC-A (data collection); Jill Chinnici, MA, CCC-A (data collection); James Clark, MD (data assembly); Howard W. Francis, MD (surgeon); Rick Ostrander, EDD (data collection); and Jennifer Yeagle, MEd, CCC-A (data collection).
Johns Hopkins University, The River School, Washington, DC: Nancy Mellon (administration); Meredith Ouellette (coordinator); Meredith Dougherty (data collection); Julie Verhoff, AuD, CCC-A (data collection); Dawn Marsiglia, MA, CCC-A/SLP (data collection); and Mary O’Leary Kane, MA, CCC-SLP (former coordinator, data assembly).
University of Miami, Miami, FL: Annelle Hodges, PhD, CCC-A (principal investigator); Thomas Balkany, MD (surgeon); Alina Lopez, MA, CCC-SLP/A (coordinator); and Leslie Goodwin, MSN, CCRC (data collection).
University of Michigan, Ann Arbor, MI: Teresa Zwolan, PhD, CCC-A (principal investigator); Caroline Arnedt, MA, CCC-A (clinic coordinator); Hussam El-Kashlam, MD (surgeon); Kelly Starr, MA, CCC-SLP (data collection); Ellen Thomas, MA, CCC-SLP (data collection).
University of North Carolina, Carolina Children’s Communicative Disorders Program, Chapel Hill, NC: Holly F.B. Teagle, AuD, CCC-A (principal investigator); Craig A. Buchman, MD (surgeon); Carlton Zdanski, MD (surgeon); Hannah Eskridge, MSP (data collection); Harold C. Pillsbury, MD (surgeon); and Jennifer Woodard (coordinator).
The University of Texas at Dallas, Dallas Cochlear Implant Program, Callier Advanced Hearing Research Center, Dallas, TX: Emily A. Tobey, PhD, CCC-SLP (principal investigator); Lana Britt, AuD,CCC-A (co-coordinator); Janet Lane, MS, CCC-SLP (data collection); Peter Roland, MD (surgeon); Sujin Shin, MA (data collection); Madhu Sundarrajan, MS,CCC-SLP (data collection); and Andrea Warner-Czyz, PhD, CCC-A (co-coordinator).
Data Coordinating Center, Johns Hopkins University, Welch Center for Prevention, Epidemiology & Clinical Research, Baltimore, MD: Nae-Yuh Wang, PhD (principal investigator, biostatistician); Christine Carson, ScM (study manager, data analysis); Patricia Bayton (data assembly); Enrico Belarmino (data assembly); Thelma Grace (data assembly); Sneha Verma (data assembly).