Associations Between Syntax and the Lexicon Among Children With or Without ASD and Language Impairment

Five groups of children defined by presence or absence of syntactic deficits and autism spectrum disorders (ASD) took vocabulary
tests and provided sentences, definitions, and word associations. Children with ASD who were free of syntactic deficits demonstrated
age-appropriate word knowledge. Children with ASD plus concomitant syntactic language impairments (ASDLI) performed similarly
to peers with specific language impairment (SLI) and both demonstrated sparse lexicons characterized by partial word knowledge
and immature knowledge of word-to-word relationships. This behavioral overlap speaks to the robustness of the syntax–lexicon
interface and points to a similarity in the ASDLI and SLI phenotypes.