韻律線索對輕度自閉症和一般兒童理解非字面語言之諷刺意涵的影響

Effect of Prosody on the Understanding of Irony in Nonliteral Language among Mildly Autistic and Typically Developing Children

關於輕度自閉症（簡稱輕度ASD）兒童使用韻律線索理解非字面語言之諷刺意涵的表現，過去研究僅有初步的探究，且未有定論。本研究目的在於探究輕度ASD兒童與一般兒童在不同韻律線索下對不同類型諷刺言語之意涵的理解表現。本研究以20名輕度ASD兒童與20名一般兒童（總計40名8—12歲國小中高年級學童）為研究對象，測量此兩組兒童在自編的語言理解作業中聆聽中性韻律線索和諷刺韻律線索時，對5種不同類型諷刺言語（「語意倒置」、「誇張」、「輕描淡寫」、「與先前對話不相關的回答」和「讚美」）的理解情形。結果發現：相較於一般兒童，輕度ASD兒童在諷刺言語的理解表現較弱，但豐富的諷刺韻律線索可提升兩組兒童理解諷刺言語之表現，兩組兒童的諷刺言語理解表現因諷刺類型不同而有所差異，而兩組兒童皆傾向於按照字面意義來理解諷刺言語。進一步分析發現，不同韻律版本、諷刺類型在兒童諷刺言語的理解表現上存在交互作用。另一方面，兒童在聆聽諷刺韻律線索時，對諷刺言語的理解表現與自身整體和部分向度的溝通能力相關。本研究結果支持，口語韻律線索的提供會影響輕度ASD兒童和一般兒童理解不同類型之諷刺言語的表現，推測韻律線索是兒童理解諷刺言語的重要線索。

Children with mild autism spectrum disorder (ASD) tend to overlook social contextual and nonverbal cues in real-life social interactions because of their psychological characteristics. They often rely solely on literal meaning to understand the intended purpose of speech, resulting in the misinterpretation of nonliteral language used by others.
Irony is a nonliteral language commonly used in everyday communication. Difficulties in understanding ironic language may affect how individuals socially communicate. Research into how individuals with mild ASD understand irony has yielded inconsistent results. While many studies have suggested that individuals with mild ASD face difficulties in understanding ironic language, some studies have indicated that they can both recognize and understand irony to a certain extent. Therefore, further investigation of whether children with mild ASD understand ironic language is warranted.
Ironic language typically consists of verbal and nonverbal cues, with prosodic cues serving as key verbal cues for understanding the intended message conveyed by others. These prosodic cues can be used to differentiate between ironic and nonironic language. Few studies have examined whether children with mild ASD can utilize prosodic cues to understand ironic language, and these studies have yielded inconsistent results. Therefore, further research is required to determine whether children with mild ASD can better understand ironic language through prosodic cues.
To address the aforementioned gap in research, this study aimed to compare children with mild ASD and typically developing children with respect to how well they understand the meaning of different types of ironic language with different prosodic cues. Specifically, this study (1) compared the performance of children with mild ASD and typically developing children in understanding the nonliteral meaning of ironic language; (2) determined whether prosodic cues influence children’s understanding of the nonliteral meaning of ironic language; (3) compared the performance of children in understanding different types of ironic language; (4) identified correlations of children’s disability status (mild ASD or typical development), prosodic cues, and irony type with performance; and (5) identified the factors associated with understanding ironic language among children.
A total of 40 children aged 8–12 years, including 20 children with mild ASD and 20 age-matched typically developing controls, were examined. All children completed a self-developed task to measure their understanding of irony. They listened to audio stimuli containing neutral prosodic cues and ironic prosodic cues, and their understanding of five distinct types of ironic language (semantic inversion, hyperbole, understatement, meaning replacement, and praise) was evaluated. During formal testing, two task versions were randomly presented, with 40 mixed stimuli presented on a computer screen as visual prompts. The audio stimuli contained dialogue scenarios narrated by the researchers (e.g.,“Xiaomei and Daxiong are taking a walk;Xiaomei walks very slowly. Daxiong says:…”). Ironic utterances (e.g.,“Xiaomei, you walk so slowly,”corresponding to the aforementioned scenario) were spoken by an adult or a student assuming the role of the character in the scenario, only in audio form without simultaneous visual cues. After audio playback, comprehension questions (e.g.,“What does Daxiong really mean by this statement?”) and four answer options were presented on the following page to enable the children to form a judgment by selecting the correct answer (1, 2, 3, or 4) on a keyboard. Finally, the percentage of correct answers was calculated to determine the ability of each child to understand ironic language.
During the computer-based language comprehension task, the primary caregivers of the children completed the Taiwanese version of the Children’s Communication Checklist—Second Edition (CCC-2) in a separate quiet room. This checklist was used to evaluate the children’s communication ability across different dimensions and identify correlations between their performance in understanding ironic language and their communication skills.
Mixed-design three-way analysis of variance (ANOVA) was conducted with different groups (mild ASD group and typically developing group), prosody versions (neutral prosody and ironic prosody), and irony types (semantic inversion, hyperbole, understatement, meaning replacement, and praise) as the independent variables and the accuracy of irony understanding as the dependent variable. Post hoc comparisons were conducted if the main effects were detected for each independent variable. Simple main effects tests and post hoc comparisons were conducted if interactions were identified between the variables. To analyze error types, a mixed-design three-way ANOVA was conducted with different groups, prosody versions, and error types (literal meaning, related message, and interpretation) as the independent variables and the frequency of each error type as the dependent variable. Post hoc comparisons were also conducted if the main effects were detected for each variable. In addition, simple main effects tests and post hoc comparisons were conducted if interactions were detected between the independent variables. Finally, Pearson’s product-moment correlations were used to examine the correlations of comprehension performance with background variables (age, estimated intelligence quotient) and dimensions of communication ability (overall communication composite score and subscale scores of the CCC-2).
Regardless of the presence of ironic prosody and the type of irony, children with mild ASD exhibited lower performance in understanding ironic language compared with typically developing children at a similar age and with similar intelligence quotient levels. This finding is consistent with previous research indicating that children with mild ASD exhibit lower performance in understanding irony compared with typically developing children. Further examination of the difficulties that children face in understanding the nonliteral meaning of ironic utterances revealed that both typically developing children and children with mild ASD tended to make the same error of interpreting ironic language depending on its literal meaning, regardless of whether they were exposed to neutral prosody or ironic prosody. This finding is consistent with previous research suggesting that individuals with ASD tend to rely solely on the literal meaning of language, which often results in the misinterpretation and misinference of others’intended messages. Rich prosodic cues improved the understanding of ironic language for the two groups of children, indicating that prosody plays a key role in understanding ironic language and that children with ASD can utilize prosodic cues to recognize and understand the intended meaning of ironic language.
In terms of irony type, the children exhibited higher performance in understanding hyperbole and meaning replacement but lower performance in understanding semantic inversion, understatement, and praise. Prosodic cues enhanced their understanding of semantic inversion, understatement, and praise but did not enhance their understanding of hyperbole and meaning replacement. These findings indicate that children tend to rely on contextual cues rather than on prosodic ones to understand the intended meaning of ironic language involving hyperbole and meaning replacement. By contrast, they tend to rely on rich prosodic cues rather than on contextual ones to understand the intended meaning of ironic language involving semantic inversion, understatement, and praise.
A further examination of the factors associated with the children’s understanding of ironic language revealed that performance was correlated with overall communication ability, speech ability, grammatical ability, narrative cohesion ability, pragmatic ability (e.g., topic initiation ability), stereotypical language identification ability, contextual ability, and nonverbal communication ability. This finding not only indicates that understanding ironic language while listening to prosodic cues may involve multiple dimensions of communication ability but also is consistent with the notion that linguistic ability is a highly crucial predictor of nonliteral linguistic comprehension. Therefore, future research seeking to enhance children’s understanding of ironic language should target various aspects of communication ability.
In summary, prosodic cues play a key role in understanding irony among children because these cues influence how children with mild ASD and typically developing children understand different types of ironic language.