Characterizing the Impact of Auditory Experience on Language, Cognitive, and Neural Development in Children

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Project Summary/Abstract: Research Project (3) Characterizing the Impact of Auditory Experience on Language, Cognitive, and Neural Development in Children It is well-established that children with hearing loss are at risk for language and academic deficits. Hearing loss is also known to impact cognitive measures such as working memory, and language ability positively correlates with these higher-order cognitive skills. However, delays in children with hearing loss are not universal; some fall significantly behind children with normal hearing (CNH), while others perform similarly to CNH. Recent work in children with mild-to-severe hearing loss (i.e., children who are hard-of-hearing (CHH)) who wear hearing aids (HAs) suggests that the severity of language delays correlates with auditory dosage, an index of auditory experience defined by HA audibility, or the degree to which a HA improves access to speech, and the amount of HA use. Taken together, language, cognitive function, and auditory experience appear to be tightly linked, and a combination of these factors likely explains much of the variability in outcomes in CHH. However, there is currently no overall framework that captures these relationships. It is difficult to probe the interactions between language and cognition using behavioral tests, as they rely on end-point metrics and cannot evaluate cognitive processing in real-time; thus, an investigation of the central neural mechanisms is crucial. The proposed project will provide pivotal new data on the impact of auditory experience on cognitive, language, and neural function in children. Our groundbreaking preliminary work has shown altered neural dynamics during higher-order cognitive processing in CHH relative to CNH, and that these neural aberrations are significantly linked with the amount of HA use and language ability. In the current study, we will probe the interactions between auditory experience, language, and cognition using an innovative multimodal approach. Specifically, we will enroll a large cohort of CHH and demographically matched CNH and all will undergo magnetoencephalographic imaging during verbal and nonverbal cognitive tasks, structural MRI, and a battery of neuropsychological and audiometric tests. In Aim 1, we will identify differences in behavior and neurophysiology during verbal and nonverbal cognition in CHH and CNH. We posit that CHH will exhibit altered neural activity in fronto-parietal language regions during verbal cognitive tasks, while executive function and memory networks will be atypical during nonverbal cognitive tasks. In Aim 2, we will determine which neural markers of higher-order cognitive processing predict language ability, and how the relationships between language and neural function are altered in CHH. We hypothesize that neural activity during nonverbal cognition will predict language function above and beyond neural markers of verbal cognitive processing. In Aim 3, we will clarify the impact of auditory dosage on language, cognitive, and neural function in CHH. We posit that auditory dosage will mediate the relationships between behavioral outcomes and neural dynamics in CHH. This study will provide direct physiological evidence linking language development and higher-order cognition in the context of hearing loss, which will lead to better-informed, individualized therapeutic approaches for CHH.