Author Description

Theoretical Background: Appropriately decoding and recognizing facial expressions is a substantial ability that develops very early in infancy and is crucial for the understanding of and adaptation to social interactions (Thomas, De Bellis, Graham, & LaBar, 2007). Furthermore, in humans and other primates, facial expressions serve as important social cues to regulate behavior and for establishing and maintaining social relationships (Kringelbach & Rolls, 2003). Studies with normal adults showed that they direct most of their attention to the core features of the face (i.e. eyes, nose, and mouth) and spend less time on non-feature areas while exploring facial expressions (Pelphrey et al., 2002). Within the core features, the eyes are considered to provide humans with the most information in terms of emotion recognition. Numerous studies confirmed this bias towards inspecting the eyes from very early in ontogeny (Holmes, Richards, & Green, 2006; Walker-Smith, Gale, & Findlay, 1977). Deficits in emotion recognition and eye-to-eye gaze are core symptoms of various disorders with difficulties in social interactions (e.g. autism, schizophrenia, borderline personality disorder, social phobia, etc.). In addition, individuals with a personality trait called alexithymia have distinct difficulties in recognizing emotions. Alexithymia is a non-clinical, psychological concept defined by difficulties in understanding and regulating emotions. The neuropeptide oxytocin (OT) is well known for its physiological functions in milk ejection and during labour. Apart from these functions, OT receptors are distributed in various brain areas associated with social behavior (for a review, see Heinrichs & Domes, 2008). Given that oxytocin is believed to promote social attachment in non-human mammals and approach behavior – such as trust – in humans, we hypothesized that oxytocin might also promote the ability to infer the mental state of others from social cues of the eye region in subject