ThinkIR: The University of Louisville\u27s Institutional Repository
Abstract
For typically developing (TD) children, maternal language input (MLI) is an important contributor to early language development. Until now, possible relations between MLI and language development for children with Williams syndrome (WS), a genetic neurodevelopmental disorder associated with language delay and intellectual disability, have not been addressed. The aim of the present study was two-fold: to examine concurrent relations between MLI and child language abilities at 24 months and to determine if individual differences in MLI and children’s lexical and cognitive abilities at 24 months make significant unique contributions to the variance in child language abilities at 48 months for children with WS. Participants included 34 mother-child dyads. Lexical diversity (number of different words; NDW) and grammatical complexity (mean length of utterance in morphemes; MLUm) measures of MLI were assessed during a 30-minute naturalistic play session at 24 months of age. For the child, standardized assessments of language and cognitive ability, as well as lexical (NDW) and grammatical (MLUm) ability measures from the play session were collected at 24 and 48 months of age. Mothers also completed a parent-report measure of child lexical and grammatical abilities at both ages. Concurrent relations between MLI and child measures of language and cognitive development were significant for maternal NDW but not for maternal MLUm. Regression analyses indicated that maternal NDW contributed significant unique variance to child receptive language at 48 months, even after taking into account child 24-month expressive vocabulary and 24-month nonverbal reasoning ability. Maternal MLUm accounted for significant unique variance in child receptive language and child MLUm at 48 months, even after accounting for the contributions of child 24-month expressive vocabulary and nonverbal reasoning ability. Implications of these findings are discussed
