Oxytocin effects on emotion recognition under conditions of unlimited and limited awareness

Abstract

The present thesis comprises a series of studies investigating the effects of oxytocin on facial emotion recognition. Study I and Study II examined whether the effects of oxytocin on emotion recognition are related to shifts in overt and/or covert attention. To this end, participants’ eye gaze and pupil size were recorded while they performed an emotion recognition task that involved the presentation of dynamically changing expressions. Oxytocin enhanced participants’ recognition sensitivity for all expressions, irrespective of the expressions’ emotional valence. These effects appeared to be due to shifts in covert rather than overt attention because oxytocin affected participants’ pupil size but not eye gaze during face processing. Study III further examined whether oxytocin-induced changes in emotion recognition are unrelated to shifts in overt attention. To this end, participants performed an emotion recognition task that involved the masked presentation of static expressions. Oxytocin enhanced participants’ recognition accuracy for all expressions, presumably due to shifts in covert rather than overt attention because the task design precluded any gaze changes during face processing. Taken together these studies suggest that oxytocin generally improves the recognition of various facial expressions, even in the absence of overt attention shifts.