Abstract
Face pareidolia is the human tendency to see illusory human-like faces, for example in random patterns exhibiting configural properties of a face. Past research on humans show that oxytocin has a crucial role in enhancing facial processing. By leading to an increased focus on the face in general, and eyes especially, alter the encoding and conceptual recognition of social stimuli, enhancing sensitivity to hidden emotions in facial expressions, and enhancing the ability to interpret the facial cues of others, oxytocin has been proposed to promote prosocial behavior in humans. In this study, we evaluated whether oxytocin modified responses to illusory face perception at an earlier perceptual, bottom-up stage of processing during limited time in the visual search task. In a double blind, randomized, placebo-controlled, within-subject design, oxytocin (24 IU) and placebo was administered to 24 healthy volunteers in two different sessions. Results revealed that random elements were perceived as a face when organized together within a configural facial distance, showing that illusory facial elements both attract pre-attentive attention resources and stands out from background of other objects and natural elements. Random elements presented in a scrambled fashion were not perceived as faces. Oxytocin did not, however, influence the accuracy of detecting pareidolia compared to placebo. Neither response time, nor confidence, gaze toward illusory faces or eyes were enhanced by the neuropeptide. The results of this study suggest that oxytocin may not influence the detection of illusory faces at early perceptual levels of processing. On the other hand, oxytocin may prove to have greater influence in altering the cognitive processing of social valence at more conceptual and elaborate levels of processing.