Characterizing Multimodal Language Input and Development in DeafBlind Children - Decades of research in language development demonstrate that the quantity and quality of linguistic input are powerful predictors of children’s language outcomes across cultures and populations. A growing body of research also points to the role of direct sensory experience in children’s learning; children are quicker to learn words whose referents they can perceive through the senses. DeafBlind children, who have reduced access to both auditory and visual information, provide a natural test case for the role of sensory perception in learning. Furthermore, because neither spoken nor sign language is fully accessible, DeafBlind children are growing up with only partial access to the language around them. The amount of language access varies based on children’s individual hearing and vision levels, combined with the family’s chosen communication strategies. By studying this unique population, we can thus test the resilience and constraints of the link between language input and language development. DeafBlind children often experience severe and persistent language delays. Given the importance of language input for language development, and the role of language in navigating the world, forming interpersonal relationships, and academic outcomes, it is imperative to better understand the relationship between DeafBlind children’s language environment, their access to the language in their environment, and their language outcomes. In the proposed work, we gather data on the early language input and vocabulary of DeafBlind children, which in many cases spans multiple languages and multiple language modalities (spoken, signed, tactile). In Aim 1, we adapt a measure of language input to estimate both the frequencies of language input and the amount of that input that is perceptually accessible to the DeafBlind child. This will clarify how parents make communicative decisions for their DeafBlind child, and how parents linguistically adapt to variation in their child’s visual and auditory ability. To complement this measure, and to capture the moment-to-moment dynamics of language access, we will curate a multi-modal corpus of naturalistic interactions between caregivers and their DeafBlind children, focusing on when the referents of caregiver speech are perceptually accessible to children. A critical next step is to understand how variability in language access relates to DeafBlind children’s language development. In Aim 2, we measure DeafBlind children’s vocabulary, and link vocabulary growth to their perceptual abilities and language input. Throughout every step of the process, a community advisory board—composed of DeafBlind adults, parents of DeafBlind children, and teachers and clinicians—will be actively involved to ensure the assessments are linguistically appropriate for DeafBlind children and relevant to the needs of their teachers and educators. Together, these data will provide critical insights into the early language landscape of DeafBlind children, and contribute to the broader, basic-scientific study of how sensory perception and language input shape children’s early language development.
