Neural Dynamics underlying Sensory Processing in Children with Mild-to-Severe Hearing Loss

Summary/Abstract Children with mild-to-severe hearing loss (i.e., children who are hard-of-hearing [CHH]) are at a heightened risk for developmental delays in language and cognitive ability compared to children with normal hearing (CNH), despite early detection and intervention. It is well-appreciated that the ability to adequately process sensory stimuli is crucial for downstream cognitive and language processing, and recent studies suggest that auditory experience, including degree of hearing loss, amount of hearing aid use, and aided audibility, plays a major role in cognitive and language ability in CHH. Despite such knowledge, the impact of mild-to-severe hearing loss and subsequent hearing aid intervention parameters on the cortical dynamics serving sensory processing, both in the auditory domain and in other sensory domains, remains poorly characterized. Thus, a better understanding of the impact of mild-to-severe hearing loss on the neural dynamics underlying key sensory processing parameters may help identify the root of alterations in behavioral outcomes in CHH. Our groundbreaking preliminary data indicates that CHH exhibit cortical hyper-responsivity to both auditory and non-auditory sensory stimuli, and that the integrity of sensory gating and sensory entrainment dynamics uniquely predict academic and verbal outcomes in CHH. Such aberrations in fundamental sensory responses indicate major therapeutic targets that must be rectified to optimize outcomes in CHH. The current study will expand on these preliminary findings to probe the impact of mild-to-severe hearing loss on sensory processing parameters and their relationships to cognitive and language development using a novel multimodal imaging approach that combines magnetoencephalography, structural MRI, and comprehensive neuropsychological and audiometric testing. In Aim 1, we will determine the neural dynamics underlying sensory gating in CHH and demographically matched CNH, and quantify how differences in gating-related neural markers predict developmental outcomes. We posit that CHH will exhibit cortical hyper-responsivity to sensory input across all modalities relative to CNH, while gating will remain intact. We also hypothesize that the integrity of sensory gating will predict cognitive and language ability in CHH, but not CNH. In Aim 2, we will identify the brain dynamics serving sensory entrainment in CHH and CNH, and quantify how variability in entrainment response dynamics predict developmental outcomes. We predict that CHH will show altered dynamics during sensory entrainment, and these alterations will uniquely relate to cognitive and language outcomes in CHH. In Aim 3, we will probe how individual differences in auditory experience impact the neural dynamics underlying sensory gating and entrainment in CHH. We predict that milder degrees of hearing loss, greater hearing aid use, and better aided audibility will “normalize” the cortical dynamics serving sensory gating and entrainment and will be related to better outcomes. This study will provide direct physiological evidence linking sensory processing to language and cognitive ability in CHH, which will lead to new, optimized, and individualized therapeutic approaches for this underserved population.