Abstract
Oxytocin (OT) is a neuropeptide that is well known for its effects on social cognition (Ebert & Brüne, 2017). Suppression of oscillatory activity in the mu/alpha and beta bands is associated with social cognitive processes, such as the perception of biological motion (Perry et al., 2010) and facial emotions (Moore et al., 2012). It has been shown that intranasal OT delivery enhances both mu and beta desynchronisation in electroencephalography (EEG) signals during the viewing of biological motion (Perry et al., 2010). Here, we investigated whether OT influences EEG oscillatory responses to emotional faces. In a double-blind, placebo-controlled, within subjects design, thirty healthy, young males were administered intranasal sprays of 24 IU of OT and placebo. After a delay of 45 minutes, participants viewed images of faces with fearful, neutral and happy expressions. In the 100–300ms time window after viewing neutral and fearful faces, desynchronisation in the low (8–10 Hz) and high (10–12 Hz) alpha/mu ranges was significantly stronger after OT than placebo delivery for a frontal, left-lateralised cluster of electrodes. However, OT did not significantly affect oscillatory responses to happy faces, nor did it affect oscillatory responses in the beta band (15–20 Hz). These results suggest that even at relatively early stages of visual processing, OT can affect facial emotion processing, and it may mediate the allocation of cortical processing resources towards socially relevant information.
Acknowledgement: LH and DC were supported by the Australian Research Council (ARC) (150104172). Nasal sprays were purchased with funding from Swinburne University of Technology and the Australian Catholic University.