Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Speech, Language, and Hearing Sciences, and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
Prog Neurobiol. 2021 Aug;203:102077. doi: 10.1016/j.pneurobio.2021.102077. Epub 2021 May 24.
Autism spectrum disorder (ASD) is associated with widespread receptive language impairments, yet the neural mechanisms underlying these deficits are poorly understood. Neuroimaging has shown that processing of socially-relevant sounds, including speech and non-speech, is atypical in ASD. However, it is unclear how the presence of lexical-semantic meaning affects speech processing in ASD. Here, we recorded magnetoencephalography data from individuals with ASD (N = 22, ages 7-17, 4 females) and typically developing (TD) peers (N = 30, ages 7-17, 5 females) during unattended listening to meaningful auditory speech sentences and meaningless jabberwocky sentences. After adjusting for age, ASD individuals showed stronger responses to meaningless jabberwocky sentences than to meaningful speech sentences in the same left temporal and parietal language regions where TD individuals exhibited stronger responses to meaningful speech. Maturational trajectories of meaningful speech responses were atypical in temporal, but not parietal, regions in ASD. Temporal responses were associated with ASD severity, while parietal responses were associated with aberrant involuntary attentional shifting in ASD. Our findings suggest a receptive speech processing dysfunction in ASD, wherein unattended meaningful speech elicits abnormal engagement of the language system, while unattended meaningless speech, filtered out in TD individuals, engages the language system through involuntary attention capture.
自闭症谱系障碍 (ASD) 与广泛的接受性语言障碍有关，但这些缺陷的神经机制仍不清楚。神经影像学研究表明，包括言语和非言语在内的与社会相关的声音处理在 ASD 中是异常的。然而，目前尚不清楚词汇语义的存在如何影响 ASD 中的言语处理。在这里，我们记录了自闭症患者 (N = 22，年龄 7-17 岁，女性 4 名) 和典型发育 (TD) 同龄人的脑磁图数据 (N = 30，年龄 7-17 岁，女性 5 名) 在不注意聆听有意义的听觉言语句子和无意义的 jabberwocky 句子时。在调整年龄后，与 TD 个体在同样的左颞叶和顶叶语言区域对有意义的言语句子表现出更强的反应相比，ASD 个体对无意义的 jabberwocky 句子表现出更强的反应。ASD 中的颞叶区域的有意义言语反应的成熟轨迹是异常的，而顶叶区域则没有。颞叶反应与 ASD 严重程度有关，而顶叶反应与 ASD 中的异常不自主注意力转移有关。我们的研究结果表明，ASD 存在接受性言语处理功能障碍，即无注意的有意义言语会引起语言系统的异常参与，而在 TD 个体中被过滤掉的无注意的无意义言语则通过不自主注意力捕获引起语言系统的参与。
