Bagherzadeh-Azbari Shadi, Lau Gilbert Ka Bo, Ouyang Guang, Zhou Changsong, Hildebrandt Andrea, Sommer Werner, Lui Ming
Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany.
Center for Child Development, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China.
Front Hum Neurosci. 2022 Feb 15;16:733852. doi: 10.3389/fnhum.2022.733852. eCollection 2022.
According to the shared signal hypothesis (SSH) the impact of facial expressions on emotion processing partially depends on whether the gaze is directed toward or away from the observer. In autism spectrum disorder (ASD) several aspects of face processing have been found to be atypical, including attention to eye gaze and the identification of emotional expressions. However, there is little research on how gaze direction affects emotional expression processing in typically developing (TD) individuals and in those with ASD. This question is investigated here in two multimodal experiments. Experiment 1 required processing eye gaze direction while faces differed in emotional expression. Forty-seven children (aged 9-12 years) participated. Their Autism Diagnostic Observation Schedule (ADOS) scores ranged from 0 to 6 in the experiment. Event-related potentials (ERPs) were sensitive to gaze direction and emotion, but emotion processing did not depend on gaze direction. However, for angry faces the gaze direction effect on the N170 amplitude, as typically observed in TD individuals, diminished with increasing ADOS score. For neutral expressions this correlation was not significant. Experiment 2 required explicit emotion classifications in a facial emotion composite task while eye gaze was manipulated incidentally. A group of 22 children with ASD was compared to a propensity score-matched group of TD children (mean age = 13 years). The same comparison was carried out for a subgroup of nine children with ASD who were less trained in social cognition, according to clinician's report. The ASD group performed overall worse in emotion recognition than the TD group, independently of emotion or gaze direction. However, for disgust expressions, eye tracking data revealed that TD children fixated relatively longer on the eyes of the stimulus face with a direct gaze as compared with averted gaze. In children with ASD we observed no such modulation of fixation behavior as a function of gaze direction. Overall, the present findings from ERPs and eye tracking confirm the hypothesis of an impaired sensitivity to gaze direction in children with ASD or elevated autistic traits, at least for specific emotions. Therefore, we conclude that multimodal investigations of the interaction between emotional processing and stimulus gaze direction are promising to understand the characteristics of individuals differing along the autism trait dimension.
根据共享信号假说（SSH），面部表情对情绪加工的影响部分取决于目光是朝向还是远离观察者。在自闭症谱系障碍（ASD）中，人们发现面部加工的几个方面存在异常，包括对目光注视的关注以及情绪表情的识别。然而，关于目光方向如何影响正常发育（TD）个体和ASD个体的情绪表情加工，相关研究较少。本文通过两个多模态实验对这一问题进行了研究。实验1要求在面部情绪表情不同的情况下处理目光方向。47名儿童（9至12岁）参与了实验。他们在实验中的自闭症诊断观察量表（ADOS）得分在0至6分之间。事件相关电位（ERP）对目光方向和情绪敏感，但情绪加工并不依赖于目光方向。然而，对于愤怒的面孔，如在TD个体中通常观察到的那样，目光方向对N170波幅的影响随着ADOS得分的增加而减弱。对于中性表情，这种相关性不显著。实验2要求在面部情绪复合任务中进行明确的情绪分类，同时对目光进行偶然操纵。将一组22名患有ASD的儿童与一组倾向得分匹配的TD儿童（平均年龄 = 13岁）进行比较。根据临床医生的报告，对9名社交认知训练较少的患有ASD的儿童亚组进行了同样的比较。ASD组在情绪识别方面总体上比TD组差，与情绪或目光方向无关。然而，对于厌恶表情，眼动追踪数据显示，与回避目光相比，TD儿童在直接注视刺激面孔的眼睛上的注视时间相对较长。在患有ASD的儿童中，我们没有观察到注视行为随目光方向的这种调节。总体而言，目前来自ERP和眼动追踪的研究结果证实了ASD儿童或自闭症特征较高的儿童对目光方向的敏感性受损的假设，至少对于特定情绪是如此。因此，我们得出结论，对情绪加工与刺激目光方向之间相互作用的多模态研究有望理解沿自闭症特征维度不同个体的特征。
