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

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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.