Effects of oxytocin on facial mimicry in autism - linking social attention and facial emotion recognition

自闭症谱系障碍(ASD)的特征通常是社会交流和相互社会互动方面的障碍，以及有限的专业兴趣和重复行为。此外，自闭症患者在对面部表情的自发模仿中表现出变化。在过去的十年里，许多研究表明催产素对人类的社会认知有积极的影响，包括社交突显、情感识别和同理心。我们目前的研究项目《催产素对社会注意的行为影响和神经相关性》(Do1312/2-1)旨在研究催产素是否调节自闭症和典型发育个体对社会刺激及其神经底物的注意。初步结果表明，催产素增加了健康人对积极社交线索的隐蔽注意力，并促进了自闭症患者的面孔加工。拟议的后续项目的直接目标是确定中枢神经催产素可获得性增加对自闭症患者面部情绪处理的影响，明确关注注意力和面部模仿的中介作用。对特定面部特征和面部模仿的关注被认为有助于健康个体的情绪识别。这两个方面都显示出自闭症的变化，因此可能导致这些人在情感识别和认知同理心方面的特征困难。通过将行为测量与电生理方法相结合来测量微妙的面部反应和凝视行为，我们寻求在自闭症和神经典型个体中分离视觉注意和模仿过程对情绪识别的独立和交互贡献。此外，催产素对这些过程的激素调节将通过双盲、安慰剂对照、交叉设计的鼻腔给药进行测试。视觉注意力的改变，特别是对相关面部特征的注意忽视，可能会阻碍对情绪表达的自发模仿。因此，眼球跟踪将用于评估社交注意过程，而对观察到的情绪表达的自发面部模仿将通过面部肌电记录进行评估。基于前面的考虑，我们预测：(I)催产素促进自闭症患者的面部模仿行为；(Ii)面部表情的模仿依赖于注意过程，特别是眼睛凝视；以及(Iii)催产素对面部模仿和情绪识别的影响是通过增加眼睛凝视来实现的。这一建议的综合方法结合了行为学、心理神经内分泌学和电生理学方法，为描述自闭症患者的面部情绪过程提供了一个独特的机会。此外，这项研究可能为考虑催产素在ASD新治疗策略中的作用提供一个切入点。

Autism spectrum disorders (ASD) are generally characterized by impairments in social communication and reciprocal social interactions, as well as a restricted range of specialized interests and repetitive behaviors. Moreover, autistic individuals show alterations in spontaneous mimicry of facially displayed emotions. Within the past decade, numerous studies have demonstrated positive effects of oxytocin on social cognition in humans including social saliency, emotion recognition and empathy. Our current research project "Behavioral effects and neural correlates of oxytocin on social attention" (Do1312/2-1) aims at investigating whether OT modulates attention to social stimuli and its neural substrates in autistic and typically developed individuals. Initial results show that oxytocin increases covert attention towards positive social cues in healthy individuals and promotes face processing in autism. The immediate objective of the proposed follow-up project is to identify the effect of increased central nervous oxytocin availability on facial emotion processing in autism, explicitly focusing on the mediating role of attention and facial mimicry. Attention to specific facial features and facial imitation are assumed to facilitate emotion recognition in healthy individuals. Both aspects show alterations in autism and may therefore contribute to characteristic difficulties in emotion recognition and cognitive empathy in these individuals. By combining behavioral measures with an electrophysiological approach to measure subtle facial reactions and gazing behavior, we seek to disentangle independent and interactive contributions of visual attention and imitation processes to emotion recognition in autistic and neurotypical individuals. Furthermore, hormonal modulation of these processes by oxytocin will be tested by intranasal administration of oxytocin in a double-blind, placebo-controlled, cross-over design. Alterations in visual attention, especially attentional neglect of relevant facial features, may hinder spontaneous imitation of emotional expressions. Therefore, eye-tracking will serve to assess social attention processes while spontaneous facial mimicry of an observed emotional expression will be assessed via facial electromyographic recordings. In the context of the previous considerations, we predict that (i) oxytocin promotes facial mimicry behavior in individuals with ASD; (ii) facial mimicry of emotional expressions depends on attention processes, particularly eye gaze; and (iii) effects of oxytocin on facial mimicry and emotion recognition are mediated by increased eye gaze. The integrative approach of this proposal, combining behavioral, psychoneuroendocrinological, and electrophysiological approaches, offers a unique opportunity for characterizing facial emotional processing in autism. In addition, this research may provide an entry point for considering the role of oxytocin in new treatment strategies in ASD.