Differences in Language Impairment Between Developmental Language Disorder and Autism: Insights From Mandarin ba and bei Constructions.

Background and aims: Both developmental language disorder (DLD) and autism spectrum disorder (ASD) are characterized by language and communication deficits, and the extent to which commonalities in syntactic difficulties are shared between DLD and autism plus language impairment (ALI), a subtype of ASD, is a matter of debate. Thus, this study aims to further explore the extent of overlapping vulnerabilities in the syntactic profiles of children with DLD and ALI.

Method: We investigated the comprehension and production of two complex syntactic structures, ba constructions and bei constructions in Mandarin by 18 children with DLD (mean age = 5;03) and 17 children with ALI (mean age = 5;05), compared to their 24 typically developing peers matched on chronological age.

Results: The results show that children with DLD and children with ALI differ in the errors committed when producing these two constructions. Specifically, children with DLD are prone to produce ungrammatical responses, use simple sentences, and misuse ba/bei constructions, while children with ALI produce pragmatically inappropriate responses which are scarce in the productions of children with DLD. In addition, the comprehension and production of bei constructions by children with DLD were significantly correlated with their nonverbal working memory (NVWM), while no such correlation was found in the ALI group. Finally, while ba and bei constructions yield higher comprehension than production in the DLD group, only ba constructions showed this pattern in the ALI group.

Conclusions: These findings suggest that children with DLD and children with ALI do not constitute a continuum of the same language disorder despite their superficial resemblance on performance accuracy.

Implications: This study highlights the need for tailored interventions to enhance mastery of ba and bei constructions: for children with DLD, focus on explicit instruction in complex syntax and NVWM training; for children with ALI, emphasize syntactic and pragmatic language development through context-rich activities integrating complex syntax and contextual cues.