Figurative language processing in autism spectrum disorders: A review

Impairments in the broader domain of pragmatics are considered to be a defining feature of Autism Spectrum Disorders (ASD). A challenging aspect of pragmatic competence is the ability to process nonliteral language. Interestingly, previous studies in figurative language comprehension in ASD have demonstrated conflicting results regarding participants' performance. The main scientific debate focuses on the underlying skills which facilitate processing of nonliteral speech in ASD. Namely, Theory of Mind (ToM), language abilities and Executive functions (EFs) are regarded as factors affecting autistic individuals' performance. This review addresses figurative language comprehension in ASD in light of the above three interpretive accounts. We reviewed data from recent studies in this field concluding that autistic children indeed encounter systematic difficulties in the processing of non-literal language. Moreover, only ToM and verbal skills were found to correlate the most with figurative language comprehension in ASD. Notably, we found that differences related to research methodology and tasks' properties may have led to discrepancies between studies' results. Finally, we argue that future studies should encompass in their experimental design figurative comprehension tasks with minimal linguistic demands and also measures of ToM, verbal ability and EFs in order to shed more light in the independent contribution of those skills to the processing of nonliteral language in ASD.

Metaphor comprehension and production in verbally able children with Autism Spectrum Disorder

Research in the field of figurative language processing in Autism Spectrum Disorders (ASD) has demonstrated that autistic individuals experience systematic difficulties in the comprehension of different types of metaphors. However, there is scarce evidence regarding metaphor production skills in ASD. Importantly, the exact source of metaphor processing difficulties in ASD remains largely controversial. The debate has mainly focused on the mediating role of structural language skills (i.e., lexical knowledge) and cognitive abilities (i.e., Theory of Mind and executive functions) in ASD individuals' ability to comprehend and generate metaphors. The present study examines metaphor comprehension and production in 18 Greek-speaking verbally able children with ASD and 31 typically-developing (TD) controls. Participants completed two tasks, namely, a low-verbal multiple-choice sentence-picture matching task that tested their ability to comprehend conventional predicate metaphors, and a sentence continuation task that assessed their ability to generate metaphors. The study also included measures of fluid intelligence, expressive vocabulary, and working memory within the sample. The results show that the ASD group had significantly lower performance than the TD group in both metaphor comprehension and production. The findings also reveal that expressive vocabulary skills were a key factor in the metaphor comprehension and production performance of the children with ASD. Working memory capacity was also found to correlate significantly with metaphor comprehension performance in the ASD group. Conversely, no correlations were found in the TD group with neither of the above factors. Of note, children with ASD generated significantly more inappropriate responses and no-responses to the metaphor production task compared with the control group. The overall results reveal that children with ASD had difficulty with both comprehending and using metaphorical language. The findings also indicate that TD children may employ diverse cognitive strategies or rely on different underlying skills when processing metaphors compared with children with ASD.

Bilingualism Effects in Metaphor and Simile Comprehension and Production in Children With Autism Spectrum Disorder

Figurative language, including metaphors and similes, is a crucial component of communication; yet, it presents significant challenges for individuals with autism spectrum disorder (ASD). A critical gap in existing research is the impact of bilingualism on the ability of children with ASD to understand and produce non-literal speech. This study addresses this gap by examining the comprehension and production of metaphors and similes in monolingual and bilingual Greek-speaking children with high-functioning ASD. To the best of our knowledge, this is the first study to investigate these abilities in bilingual children with ASD. Thirty-three monolingual and 18 bilingual children participated in tasks designed to assess comprehension, production, and error patterns for metaphors and similes. The study has also investigated the roles of non-verbal intelligence, language skills (expressive vocabulary), and executive functions (working memory) in the children's performance in the metaphor and simile tasks. Results showed that the two groups did not differ in metaphor comprehension; however, bilingual autistic children with higher non-verbal intelligence appeared to have superior performance in metaphor comprehension compared to their bilingual peers with lower non-verbal intelligence. The bilingual autistic children outperformed their monolingual peers in metaphor production, likely due to their higher non-verbal intelligence ability, despite the fact that the bilingual group had lower expressive vocabulary scores than the monolingual children. Simile comprehension, on the other hand, favored monolingual children, while no significant group differences were observed in simile production. Regarding errors, both groups exhibited similar error patterns, with literal interpretations being the dominant error type across both groups, suggesting that pragmatic language difficulty is a hallmark feature in ASD. The findings challenge the misconception that bilingualism hinders language development in children with ASD and highlight its potential to provide benefits in the realm of non-literal language processing.