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.

Barriers to early cochlear implantation

“…visual) systems (Fagan & Pisoni, 2010;Ruben, 1997;Sharma et al, 2009). Delayed access to adequate hearing not only leads to setbacks in language acquisition, but can also impact long-term academic performance, social interaction (Polat, 2003), employment, and quality of life (Markman et al, 2011). To circumvent such enduring implications of significant hearing loss, the Joint Committee of Infant Hearing aims for detection of hearing loss by one month, confirmation by three months, and intervention by six months of age; known as the 1-3-6 guidelines (JCIH, 2007;Muse et al, 2013).…”

Effects of Maternal Sensitivity and Cognitive and Linguistic Stimulation on Cochlear Implant Users' Language Development over Four Years

“…Models of early language learning have long emphasized the key role played by early caregiver interactions in facilitating communicative intent and attentional frames, setting the stage for imitative learning of linguistic expression. 8-13 Observational studies have shown that hearing mothers of young deaf children engage in more controlling, directive, and intrusive interactions with their children and display less positive affect compared with mothers of hearing children. 14-16 The consequences of these dyadic interactions include less secure attachment, difficulty sustaining attention, and slower development of communicative competence.…”

Neurociência na educação: causas, consequências e intervenções corretivas para disgrafia

“…Ao lançar mão de recursos empíricos aliados a uma análise do referencial teórico utilizado para este estudo permitiu-se ponderar sobre a qualidade da comunicação e, com isso, notar a relação entre estes dois fatores, a ponto de a linguagem influenciar a qualidade da aprendizagem, o que impõe a necessidade de se conhecer de forma mais aprofundada os conceitos e mecanismos inerentes à linguagem e sua relação com a aprendizagem, e isso pode ser sustentado na afirmação de (MARKMAN et al, 2011) de que a "A linguagem fornece as ferramentas para nos revelar aos outros no estabelecimento e manutenção de relacionamentos e impulsiona o aprendizado perceptual que contribui para a cognição." Vemos, então que a linguagem, além de ser uma forma de expressar a si mesmo, também é uma poderosa ferramenta de construção da subjetividade do indivíduo, possibilitando que este crie uma estrutura acessível de seus conhecimentos.…”