Receptive and expressive language ability differentially scaffold symbolic understanding over time: picture comprehension in late talking and typically developing children

Symbols are a hallmark of human communication, and a key question is how children’s emerging language skills relate to their ability to comprehend symbols. In particular, receptive and expressive vocabulary may have related, but distinct roles across early development. In a longitudinal study of late talking (LT) and typically developing (TD) children, we differentiated the extent to which expressive and receptive language skills predicted symbolic understanding as reflected in picture comprehension, and how language skills inter-related with social skills. LT and TD children were tested on a picture comprehension task that manipulated the availability of verbal labels at 2.0 – 2.4 years and 3.5 – 3.9 years. While all children improved in accuracy over time as expected, TD children exhibited an advantage over LT children, despite both groups utilising verbal labels to inform their mapping of picture-object relationships. Receptive and expressive vocabulary also differed in their contribution at different ages: receptive vocabulary predicted performance at ~2-years-old, and expressive vocabulary predicted performance at ~3.5-years-old. Task performance at 3.5-years-old was predicted by earlier receptive vocabulary, but this effect was largely mediated by concurrent expressive vocabulary. Social ability across the whole sample at ~2-years-old also predicted and mediated the effect of receptive vocabulary on concurrent task performance. These findings suggest that LT children may have delays in developing picture comprehension over time, and also that social ability and language skills may differentially relate to symbolic understanding at key moments across development.

Investigating the relationship between language and picture understanding in children with autism spectrum disorder

Previous studies report that minimally verbal children with autism spectrum disorder show impaired picture comprehension when matched to typically developing controls on language comprehension. Here, we compare both picture comprehension and picture production abilities in linguistically delayed children with autism spectrum disorder and typically developing controls matched on language comprehension and language production. Participants were 20 children with autism spectrum disorder ( M age: 11.2 years) and 20 typically developing children ( M age: 4.4 years) matched on age equivalents for receptive language (autism spectrum disorder, M: 4.6 years; typically developing, M: 4.5 years) and expressive language (autism spectrum disorder, M: 4.4 years; typically developing, M: 4.5 years). Picture comprehension was assessed by asking children to identify the three-dimensional referents of line drawings. Picture production was assessed by asking children to create representational drawings of unfamiliar objects and having raters identify their referents. The results of both picture tasks revealed statistically equivalent performance for typically developing children and children with autism spectrum disorder, and identical patterns of performance across trial types. These findings suggest that early deficits in pictorial understanding displayed by minimally verbal individuals may diminish as their expressive language skills develop. Theoretically, our study indicates that development in linguistic and pictorial domains may be inter-related for children with autism spectrum disorder (as is the case for typical development).