Relationships between executive functions and morphosyntactic skills in Spanish-speaking children with and without developmental language disorder

One of the primary markers of developmental language disorder (DLD) is difficulties in the development of morphosyntax. In addition, because children with DLD often have deficits in executive functions (EFs) it has been suggested that EF may be associated with their reduced ability to comprehend and produce different morphosyntactic structures. However, the specific pattern of this relationship remains unclear. The present cross-sectional study examined the association of a set of EFs with the comprehension and production of morphosyntax in a sample of Spanish-speaking children with and without DLD. A total of 204 children aged 6-8 years were assessed: 105 with DLD and 99 with typical development (TD). Multiple regression models and path analyses were performed, with EFs as predictors and morphosyntactic comprehension and production as outcome or mediating variables. The results showed that in children with DLD the EFs of verbal working memory and cognitive flexibility were directly associated with morphosyntactic comprehension and indirectly with morphosyntactic production. This indirect relationship was mediated by morphosyntactic comprehension. In TD children, there was a significant relationship only between verbal working memory and morphosyntactic comprehension. These results suggest that school-aged children with DLD depend more on EFs for morphosyntactic processing than their TD peers. Furthermore, EFs have a more critical influence on morphosyntactic comprehension than production. Interventions aimed at improving morphosyntax in DLD should include EF activities.