Effects of Syntactic Complexity on the Comprehension of Passive Clauses and wh-questions in Children with Developmental Language Disorder and Autism Plus Language Impairment.

There is considerable debate over the similarities and differences between developmental language disorder (DLD) and autism spectrum disorder plus language impairment (ALI). Few studies have compared these in terms of complex syntactic operations. This study aimed to explore the similarities and differences between children with DLD and children with ALI via investigating the effects of syntactic complexity operationalized in terms of movement and intervention in Mandarin passives and wh-questions. Fifteen Mandarin-speaking children with DLD (mean age = 60.73 months), sixteen children with ALI (mean age = 64.90 months) and twenty-five typically developing age-matched (TDA) children (mean age = 62.03 months) participated in a picture-choice task and a character-picture task. Lower-than-TDA performance and similar patterns of non-target responses were observed in the DLD and ALI groups. Short-long passive asymmetry was found in the two groups. However, who-which-question asymmetry was identified only in the ALI group, with a significant difference between who- and which-questions found only in the ALI group. Syntactic complexity affected the DLD and ALI groups similarly. The primary deficit lies in establishing a local relationship between a moved phrase and its trace in thematic role transmission when an intervenor is present. A slight difference between the two groups illustrates that DLD and ALI are not identical in language impairment, despite sharing common symptoms. This may be due to problems of children with ALI with referentiality. These findings suggest that non-target responses in language tests are worthy of in-depth analysis to confirm language disorders.