Rapid phonological coding and working memory dynamics in children with cochlear implants
Past research on cochlear implants in deaf children has been narrowly focused on speech and language outcomes and efficacy of cochlear implantation as a medical treatment for profound hearing loss. Little, if any, basic or clinical research has investigated the underlying neurobiological and cognitive factors that are responsible for the enormous individual differences and variability in the effectiveness of cochlear implants in this unique clinical population. Our research over the last twenty years has demonstrated that a small number of core elementary cognitive processes such as rapid phonological coding, working memory dynamics, processing speed, inhibition and sequence learning are strongly associated with traditional “endpoint” clinical speech and language outcome measures. These foundational cognitive processes reflect the global coordination, integration and functional connectivity of multiple underlying brain systems used in speech perception, production and spoken language processing. Our findings on the underlying sources of variability in spoken language processing provide a new theoretical framework that can help to understand and explain the enormous individual differences in speech and language outcomes following cochlear implantation. The results of our research have direct clinical implications for improving the diagnosis, treatment and early identification of young profoundly deaf children who may be at high risk for poor speech and language outcomes following cochlear implantation.