Effects of intranasal oxytocin on pupil dilation indicate increased salience of socioaffective stimuli


  • This study was financially supported by a grant from the German Research Foundation (DFG Do1312/1-1). We thank Friederike Pockrandt and Marlies Bebersdorf for assistance during data acquisition, Christoph Berger for technical support, and Gisela Irmisch for help with regard to analysis of the endocrine data.

Address correspondence to: Kristin Prehn, Freie Universität Berlin, Cluster of Excellence “Languages of Emotion,” Habelschwerdter Allee 45, 14195 Berlin, Germany, E-mail: kristin.prehn@fu-berlin.de or Gregor Domes, Department of Psychology, Laboratory for Biological and Personality Psychology, University of Freiburg, Stefan-Meier-Strasse 8, 79104 Freiburg, Germany, E-mail: domes@psychologie.uni-freiburg.de


To investigate the mechanisms by which oxytocin improves socioaffective processing, we measured behavioral and pupillometric data during a dynamic facial emotion recognition task. In a double-blind between-subjects design, 47 men received either 24 IU intranasal oxytocin (OXT) or a placebo (PLC). Participants in the OXT group recognized all facial expressions at lower intensity levels than did participants in the PLC group. Improved performance was accompanied by increased task-related pupil dilation, indicating an increased recruitment of attentional resources. We also found increased pupil dilation during the processing of female compared with male faces. This gender-specific stimulus effect diminished in the OXT group, in which pupil size specifically increased for male faces. Results suggest that improved emotion recognition after OXT treatment might be due to an intensified processing of stimuli that usually do not recruit much attention.