Comprehension of presupposition triggers in Cantonese-speaking children with and without autism spectrum disorders.
Built on a previous finding that children with autism spectrum disorders (ASD) had difficulty comprehending presuppositions, a domain of knowledge which is crucial for successful communication, the present study investigated the comprehension of seven types of presupposition trigger - namely definite descriptions, factive predicates, change-of-state verbs, implicative verbs, iteratives, temporal clauses, and counterfactual conditionals - in Cantonese-speaking children with and without ASD. Twenty-seven children with ASD (mean age 9.07) were compared with 23 typically developing (TD) children matched on chronological age and 21 TD children matched on language ability (LA). Knowledge of presupposition triggers was evaluated on the basis of children's ability to judge whether a given utterance was a correct presupposition of a preceding utterance. Children with ASD were found to perform significantly worse than TD children matched on chronological age in comprehending the seven types of presupposition trigger, but they performed similarly to TD children matched on language ability. After the effects of chronological age, language ability, and non-verbal intelligence were controlled for, children with ASD were still found to show a deficit in comprehending the presupposition triggered by a temporal clause, relative to the two groups of TD children. Future studies should investigate the factors contributing to this specific deficit in children with ASD, such as executive functioning and theory of mind.