Impaired comprehension of alternating syntactic constructions in autism

Individuals on the higher-functioning end of the autism spectrum have significant impairments in communication. Language delay can occur, particularly in syntactic or structural linguistic knowledge. However, classically observed semantic deficits generally overshadow these structural deficits. This research examined the potential effects on comprehension of dative expressions that exhibited syntactic alternation versus those that were restricted, whether in syntactic construction or through marked semantic differences in construction. Children with autism and matched neurotypical control participants were presented with a sentence battery of dative statements representing these variations in construction and were asked to display basic comprehension of the sentence meaning by identifying the recipient, or indirect object, of the dative verb. Construction, restriction, and semantic differentiation variables were analyzed for potential effects on the rate of accurate comprehension. Both groups performed with greater accuracy when dative expressions used a prepositional phrase than when the dative action was expressed in the syntax. The autism group performed more poorly when the dative expression could syntactically alternate than when it was restricted. These effects improve our knowledge of how children with autism understand alternating grammatical constructions.