Does oxytocin influence the early detection of angry and happy faces?

Oxytocin has a crucial role in social behaviour, although its effects on social cognition are not fully understood. Past research shows that oxytocin enhances encoding and conceptual recognition of positive social stimuli over social-threat stimuli. In this study, we evaluated whether oxytocin modified responses to positive and threatening social stimuli at an earlier perceptual stage of processing using the visual search task. In a double-blind, randomized, placebo-controlled, between-subject design, oxytocin (24 IU) or a placebo was administered to 104 healthy volunteers. Participants returned to complete the visual search paradigm 45 min later. Results showed that angry faces were detected more efficiently than happy faces. Participants also gazed longer and more frequently toward angry faces. Oxytocin did not, however, influence response time, accuracy, or gaze toward angry or happy faces, even when participants were separated into high- and low-social anxiety. The results of this study suggest that oxytocin may not influence the detection of positive and threatening social stimuli at early perceptual levels of processing. Oxytocin may have greater influence in altering the cognitive processing of social valence at more conceptual and elaborate levels of processing. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.