Characterizing the early vocabulary profiles of preverbal and minimally verbal children with autism spectrum disorder

Children with autism spectrum disorder often have significant language delays. But do they learn language differently than neurotypical toddlers? We compared the lexical skills of 64 preverbal and minimally verbal children with autism spectrum disorder to 461 vocabulary-size-matched typically developing toddlers. We also examined social features of verb knowledge using a novel collection of social ratings. Children with autism spectrum disorder produced proportionally more verbs than typically developing toddlers. Children with autism spectrum disorder produced proportionally more action and food words, while typically developing toddlers produced proportionally more animal, people words, and animal sounds and sound effects. Children with autism spectrum disorder also produced “mommy” and “daddy” at lower rates. We discuss how these differences may reflect an association between lexical development and weaknesses in social communication.

Although preverbal and minimally verbal children with autism spectrum disorder represent a significant portion of the autism spectrum disorder population, we have a limited understanding of and characterization of them. Although it is a given that their lexical profiles contain fewer words, it is important to determine whether (a) the words preverbal and minimally verbal children with autism spectrum disorder produce are similar to the first words typically developing children produce or (b) there are unique features of the limited words that preverbal and minimally verbal children with autism spectrum disorder produce. The current study compared the early word profiles of preverbal and minimally verbal children with autism spectrum disorder to vocabulary-matched typically developing toddlers. Children with autism spectrum disorder produced proportionally more verbs than typically developing toddlers. Also, children with autism spectrum disorder produced proportionally more action and food words, while typically developing toddlers produced proportionally more animal words, animal sounds and sound effects, and people words. Children with autism spectrum disorder also produced “mommy” and “daddy” at lower rates. Our findings identified several areas of overlap in early word learning; however, our findings also point to differences that may be connected to core weaknesses in social communication (i.e. people words). The findings highlight words and categories that could serve as useful targets for communication intervention with preverbal and minimally verbal children with autism spectrum disorder.