Everaert et al. (2023) Nonverbal executive functioning in relation to vocabulary and morphosyntax in preschool children with and without developmental language disorder. JSLHR, 66, 3954-73.
Children with Developmental Language Disorder (DLD) have a persistent language difficulty that has a significant impact on school learning and everyday interactions. Executive functions are brain-based processes that allow us to create and sustain action towards goals while acting insightfully with others. Three cognitive resources support executive functions including the ability to update information held in mind or working memory, the ability to inhibit unnecessary information which, along with working memory, allows for selective attention, and cognitive flexibility, or the ability to put things together in unique ways. There are well-recognized links between executive functions and language learning. For example, working memory can support holding novel phonological forms in mind so that new vocabulary can be learned. In addition, putting words to the steps you need to complete helps you achieve goals. Given this link, there has been interest in examining executive functions in children with DLD.
One challenge with examining executive functions in children with DLD is that many executive functions tasks involve language. Indeed, systematic reviews has reported that children with DLD differ substantially from their typically developing peers when compared on verbally-loaded executive function tasks. The group difference, however, while reliable, is considerably smaller when the groups are compared on nonverbal function tasks such as recalling the sequence of indicated blocks.
This study examined the relationship between language (vocabulary; morphosyntax) and nonverbal executive function measures in 3-6 year old children with and without DLD. The children with DLD scored significantly lower than the typically developing group on all four executive function measures. An executive function factor was found to add significant predictive value to morphosyntax but not vocabulary performance in children with DLD. For typically developing children, executive functions predicted both vocabulary and morphosyntax. Diagnosis (DLD or not) was not a significant moderator of these relationships.
These results highlight the importance of using strategies to scaffold executive functions when providing language-based interventions with a high verbal load such as sentence-level activities. Strategies might include repeating information, providing visual supports, and breaking the task into smaller steps.