Dunham-Carr Kacie, Feldman Jacob I, Simon David M, Edmunds Sarah R, Tu Alexander, Kuang Wayne, Conrad Julie G, Santapuram Pooja, Wallace Mark T, Woynaroski Tiffany G
Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.
Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, TN 37232, USA.
Brain Sci. 2023 Jul 8;13(7):1043. doi: 10.3390/brainsci13071043.
Explaining individual differences in vocabulary in autism is critical, as understanding and using words to communicate are key predictors of long-term outcomes for autistic individuals. Differences in audiovisual speech processing may explain variability in vocabulary in autism. The efficiency of audiovisual speech processing can be indexed via amplitude suppression, wherein the amplitude of the event-related potential (ERP) is reduced at the P2 component in response to audiovisual speech compared to auditory-only speech. This study used electroencephalography (EEG) to measure P2 amplitudes in response to auditory-only and audiovisual speech and norm-referenced, standardized assessments to measure vocabulary in 25 autistic and 25 nonautistic children to determine whether amplitude suppression (a) differs or (b) explains variability in vocabulary in autistic and nonautistic children. A series of regression analyses evaluated associations between amplitude suppression and vocabulary scores. Both groups demonstrated P2 amplitude suppression, on average, in response to audiovisual speech relative to auditory-only speech. Between-group differences in mean amplitude suppression were nonsignificant. Individual differences in amplitude suppression were positively associated with expressive vocabulary through receptive vocabulary, as evidenced by a significant indirect effect observed across groups. The results suggest that efficiency of audiovisual speech processing may explain variance in vocabulary in autism.
解释自闭症患者词汇方面的个体差异至关重要，因为理解和运用词汇进行交流是自闭症个体长期预后的关键预测指标。视听言语处理方面的差异可能解释自闭症患者词汇量的变异性。视听言语处理的效率可通过幅度抑制来衡量，即与仅听言语相比，对视听言语做出反应时，事件相关电位（ERP）在P2成分处的幅度会降低。本研究使用脑电图（EEG）测量对仅听言语和视听言语做出反应时的P2幅度，并使用常模参照、标准化评估来测量25名自闭症儿童和25名非自闭症儿童的词汇量，以确定幅度抑制是否（a）存在差异或（b）解释自闭症儿童和非自闭症儿童词汇量的变异性。一系列回归分析评估了幅度抑制与词汇分数之间的关联。两组在平均水平上，相对于仅听言语，对视听言语都表现出P2幅度抑制。组间平均幅度抑制的差异不显著。幅度抑制的个体差异通过接受性词汇与表达性词汇呈正相关，这在各群体中观察到的显著间接效应中得到证明。结果表明，视听言语处理效率可能解释自闭症患者词汇量的差异。
