Central coherence in relation to reading in Hong Kong bilingual children with autism spectrum disorder

Abstract

Autism Spectrum Disorder (ASD), a neurodevelopmental disorder affecting approximately 1% of the worldwide population, is characterized by impaired development of social communication, cognition, emotions and behavior. This study explores the reading behavior of Chinese-English bilinguals with ASD in Hong Kong in relation to the Central Coherence Theory. Six tasks were conducted with 22 Chinese-English bilinguals with ASD and 24 Typical Developing (TD) bilinguals to investigate reading at word and sentence levels.

In the Homograph Task, two-character words were used to investigate context effects. Participants used the local context to give appropriate pronunciations of the homographs. In the Word Recall Task, participants freely recalled a list of semantically-related and unrelated words. The results showed weaker performance of participants with ASD in using the context for retrieval, and weaker ability to use links between word representations in semantic networks. Both weak central coherence and verbal working memory affected their performance. In the Homophone Task, participants made judgements on the use of homophones based on the content of the sentence. While the results for English Homophones were consistent with previous studies, judgements of the Chinese homophones depended instead on the word level. The participants benefitted from the immediate Chinese linguistic context. In the Lexical Choice Task, participants selected a word to fill gaps in the Chinese sentences given. Participants with ASD were able to use the linguistic context to perform as well as TD participants due to the detailed-focus cognitive style and ability to focus on local features. In the Sentence Unscrambling task, participants had to reassemble scrambled words into sentences. Participants with ASD showed difficulty in integrating the scrambled information into coherent sentences. In the Vocabulary Selection Task, Participants with ASD showed no impairment in choosing mental-state words, suggesting that theory of mind was not a factor affecting their performance. Instead the participants with ASD selected fewer concrete nouns and abstract nouns than TD participants, showing their weakness in using semantic relatedness for categorization.

The findings suggested that participants with ASD ignored global features and focused on local ones, in accordance with the central coherence theory. They performed as well as TD participants given the word-level context and explicit instructions. These results contradicted previous findings in English homograph/homophone studies because in Chinese one character in a two-character word can be a contextual cue to the pronunciation of homographs or usage of homophones. Therefore, immediate linguistic context and local contextual cues facilitate ASD children’s reading of homographs/homophones in Chinese. However, they showed decreased ability to make connections or interpret the incoming linguistic information, weaker retrieval performance, difficulties in unscrambling information and decreased ability to use organizational strategies to integrate information or form meaningful links between stimuli in a semantic network, as in the Sentence Unscrambling, Vocabulary Selection and Word Recall tasks.

These findings suggest explicit short instructions benefit children with ASD. Short contextual cues help them to focus on local information in reading. Their language ability is not affected by their cognitive processing style. They have the capacity to function successfully as bilinguals.