The effects of early exposure to nonnative sign language on language acquisition and memory abilities following cochlear implantation

‍

Evidence suggests that exposure to sign language prior to implantation has important benefits for oral language development in deaf children – benefits reported for deaf children who have had early exposure to native sign language and continued their exposure post-implantation (Mayberry, 2007). However, in Quebec, a large proportion of deaf children receive early, but non-native sign input. Indeed, most deaf children are born to normal-hearing parents who try to learn sign language in order to communicate with their deaf child, thus providing them with nonnative sign input (Pierce et al., 2017). Moreover, if deaf children receive some formal sign language input during interventions provided by speech-language pathologists (SLPs), these interventions occur at best on a weekly basis. Also, deaf children’s exposure to sign language, from both SLPs and parents, is limited between the moment of their diagnostic and the moment of their implantation (CHHA, 2018). Thus, early exposure to sign language is limited because in Quebec deaf children receive their diagnostic in the first months of life and their implantation occurs between 12-24 months of age (CADTH, 2011). This raises the question whether such short exposure to nonnative sign language affects CI children’s oral language development after implantation. Also, while exposure to nonnative sign input was found to be associated with delays in the development of nonverbal WM in deaf children in comparison to hearing children and native signers with CIs (Marshall et al., 2015), no study has examined the impact of nonnative sign input on phonological memory or the impact of short-term exposure to sign language pre-implantation on phonological and nonverbal WM. Our study will examine the post-implantation effects of early but short-term nonnative sign input during the first 24 months of age on the language and memory abilities of deaf children with CIs in comparison to that of deaf children who experience long-term maintenance of sign language after implantation, deaf children with no exposure to sign language prior to implantation, and normal hearing French-speaking children. The project will control for variables specific to CI children as well as for basic cognitive abilities and background variables. Some groups (children with CIs and no prior exposure to sign language; French-speaking controls) have already been recruited and tested. We have already conducted studies on deaf children with CIs and we have access to this population. Collaborators have complementary expertise that will ensure timely progress and we will create a team comprised of competent colleagues. The project will be of interest for researchers in several areas (audiology, SLPs, psychology). Indeed, the project will examine theoretical questions that are currently prominent and important for in these domains of research–such as issues concerning delays in language acquisition. Examining the impact of a short-term nonnative exposure to sign language on CI children’s language and memory development will also inform and benefit professionals. Since most deaf children in Quebec receive this type of input before implantation, it is important determine the effects of such input to optimize speech-language/audiology interventions. The findings will provide professional development programs with guidance on how best to train professionals who work with CI children. The project will have an impact beyond the research community as we have been approached by associations and readaptation centers to present our results because they believe that this project will help them better understand and characterize their understanding of early short-term nonnative sign language input as well as these children’s strengths/weaknesses.

Chercheur principaux : François Champoux et Fred Genesee