Effects of signs on word learning by children with developmental language disorder

Purpose: The present study investigated the effects of signs on word learning by children with Developmental Language Disorder (DLD), in comparison with typically developing children (TD), and the relation between a possible sign effect and children's linguistic and cognitive abilities. Method: Nine- to eleven-year-old children with DLD (N=40) and TD children (N=2659) participated in a word learning experiment. Half of the spoken pseudo words were taught with a pseudo sign with learning outcomes being assessed in accuracy and speed. To investigate whether sign effects would hold for children with varying linguistic and cognitive abilities, we measured children's linguistic (vocabulary, syntax) and cognitive skills (divided attention, working memory (WM), lexical access). Results: The children with DLD showed a positive sign effect in both accuracy and speed. For the TD children, there was no effect of signs on word learning. Principle component analyses of the linguistic and cognitive measures evidenced a four-component solution (Language Skills, Visual WM, Verbal WM, Executive Attention). A rRepeated measures ANCOVAs with the component scores as covariates yielded no significant interactions with the linguistic and cognitive components. Conclusions: Our results suggest that children with DLD benefit from signs for word learning, regardless of their linguistic and cognitive abilities. This implies that using sign-supported speech as a means to improve vocabulary skills of children with DLD is effective, even still at the age of nine to eleven years.