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.

Comprehension of literal statements and similes in Cantonese-speaking children with and without autism spectrum disorders.

While it has been proposed, following relevance theory, that similes can be understood at a purely literal level on a par with literal statements, it remains unclear whether children with high-functioning autism spectrum disorders (HFASD) perform similarly to typically developing (TD) children in comprehending literal statements and similes. The present study investigated comprehension of literal statements and similes in Cantonese-speaking children with HFASD and TD children matched on both chronological age and verbal mental age. An utterance-picture matching task was devised to assess their comprehension of literal statements and similes in Cantonese. Overall results showed that Cantonese-speaking children with HFASD performed worse than TD children in comprehending literal statements and similes, and both groups showed more difficulty in comprehending similes than literal statements. After the effects of chronological age and verbal mental age were controlled for, no group difference was found between children with HFASD and TD children in comprehending literal statements, whereas the group difference in simile comprehension still existed, suggesting that children with HFASD showed deficits in comprehending similes relative to TD children. These findings challenge the proposal that similes can be understood at a purely literal level on a par with literal statements. Future studies should investigate the role of different aspects of language ability and different levels of theory-of-mind skills in comprehension of similes and metaphors in children with HFASD.

Comprehension of presuppositions in school-age Cantonese-speaking children with and without autism spectrum disorders.

While an enormous amount of research has been done on the deficient conversation skills in individuals with autism spectrum disorders (ASD), little is known about their performance on presuppositions, a domain of knowledge that is crucial for successful communication. This study investigated the comprehension of four types of presupposition, namely existential, factive, lexical and structural presuppositions, in school-age Cantonese-speaking children with and without ASD. A group of children with ASD (n = 21), mean age 8.8, was compared with a group of typically developing children (n = 106). Knowledge of presuppositions was evaluated based on children's ability to judge whether a given utterance was a correct presupposition of a preceding utterance. Children with ASD were found to show a deficit in the comprehension of presuppositions, even after controlling for differences in general language ability and non-verbal intelligence. The relative difficulty of the four types of presupposition did not differ between the two groups of children. The present findings provide new empirical evidence that children with ASD have a deficit in the comprehension of presuppositions. Future research should explore whether the deficit in the comprehension of presuppositions is related to the development of theory of mind skills in children with ASD.

Linguistic Tone and Non-Linguistic Pitch Imitation in Children with Autism Spectrum Disorders: A Cross-Linguistic Investigation.

The conclusions on prosodic pitch features in autism spectrum disorders (ASD) have primarily been derived from studies in non-tonal language speakers. This cross-linguistic study evaluated the performance of imitating Cantonese lexical tones and their non-linguistic (nonspeech) counterparts by Cantonese- and Mandarin-speaking children with and without ASD. Acoustic analyses showed that, compared with typically developing peers, children with ASD exhibited increased pitch variations when imitating lexical tones, while performed similarly when imitating the nonspeech counterparts. Furthermore, Mandarin-speaking children with ASD failed to exploit the phonological knowledge of segments to improve the imitation accuracy of non-native lexical tones. These findings help clarify the speech-specific pitch processing atypicality and phonological processing deficit in tone-language-speaking children with ASD.