Department of Psychology, National Taiwan University, Taipei, Taiwan.
Imaging Center for Integrated Body, Mind, and Culture Research, National Taiwan University, Taipei, Taiwan.
Autism Res. 2019 Oct;12(10):1484-1494. doi: 10.1002/aur.2184. Epub 2019 Aug 6.
Impaired language and communication are commonly observed in youths with autism spectrum disorders (ASDs). However, the organization of semantic knowledge in youths with ASD remains unclear compared to typically developing (TD) youths. The present study addresses this issue by using functional magnetic resonance imaging (fMRI) to examine the distinction between association strength and categorical relatedness of semantic knowledge. A sample of 31 male youths with ASD (mean age = 12.1 years, SD = 1.2) and 38 TD youths (mean age = 11.9 years, SD = 1.0) was recruited with matched age, gender, and handedness. Participants decided if two visually presented Chinese characters were semantically related during fMRI scanning. For weaker association strength, the ASD group showed greater left cuneus activation, which was positively correlated with the picture completion for visual perception, whereas the TD group showed greater middle temporal gyrus and inferior frontal gyrus activation. For higher categorical relatedness, the TD group showed greater activation than the ASD group in the occipitotemporal cortex and left precuneus, which was positively correlated with the similarities for concept formulation. Findings imply that the ASD group may use lower-level visual information for both association strength and categorical relatedness. The TD group showed higher-level controlled processes of more elaborate semantic representations for association strength and more elaborate features of categorical knowledge for semantic selection and integration. Autism Res 2019, 12: 1484-1494. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Individuals with autism spectrum disorder (ASD) often present language/communication impairments. Exploring the difference of semantic processing between youths with ASD and typically developing (TD) youths is crucial for understanding the organization of semantic knowledge. We found different neural substrates of semantic knowledge between these two groups. ASD youths may rely more on lower-level visual information during semantic judgments, whereas TD youths showed higher-level controlled processes of more elaborate semantic representations for selection and integration of words, phrases, and sentences.
自闭症谱系障碍（ASD）患者常伴有语言和交流障碍。然而，与典型发育（TD）青少年相比，ASD 青少年的语义知识组织仍不清楚。本研究通过使用功能磁共振成像（fMRI）来检查语义知识的联想强度和类别相关性的区别，从而解决了这一问题。研究招募了 31 名男性 ASD 青少年（平均年龄=12.1 岁，标准差=1.2）和 38 名 TD 青少年（平均年龄=11.9 岁，标准差=1.0），年龄、性别和利手相匹配。参与者在 fMRI 扫描过程中判断两个视觉呈现的汉字是否在语义上相关。对于较弱的联想强度，ASD 组表现出左侧楔前叶更大的激活，这与视觉感知的图片完成呈正相关，而 TD 组表现出更大的中颞叶和下额叶激活。对于更高的类别相关性，TD 组在枕颞叶和左侧楔前叶的激活大于 ASD 组，这与概念形成的相似性呈正相关。研究结果表明，ASD 组可能将较低水平的视觉信息用于联想强度和类别相关性。TD 组表现出更高水平的控制过程，用于更精细的联想强度语义表示，以及更精细的类别知识特征用于语义选择和整合。自闭症研究 2019, 12: 1484-1494. © 2019 自闭症国际研究协会，威利父子出版公司。 要点总结：自闭症谱系障碍（ASD）患者通常存在语言/交流障碍。探索 ASD 青少年和典型发育（TD）青少年之间语义处理的差异对于理解语义知识的组织至关重要。我们发现这两组之间存在不同的语义知识神经基础。ASD 青少年在进行语义判断时可能更多地依赖于较低水平的视觉信息，而 TD 青少年在词汇、短语和句子的选择和整合方面表现出更高水平的控制过程，以更精细的语义表示。
