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

Abstract

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.

Oxytocin Modulates Amygdala Reactivity to Masked Fearful Eyes

“…For example, there is evidence that oxytocin facilitates attentional disengagement from negative facial expressions (Domes et al, 2013b;Ellenbogen et al, 2012) and enhances the allocation of attentional resources toward positive but not negative social cues (Domes et al, 2013a;Prehn et al, 2013). In addition, decreased neural reactivity to threat cues from the eyes following oxytocin administration may contribute to its prosocial effects when evaluating negative stimuli.…”

Oxytocin improves mentalizing – Pronounced effects for individuals with attenuated ability to empathize

“…They demonstrate that OXT promotes the identification of happy faces (Guastella et al, 2008b;DiSimplicio et al, 2009;Marsh et al, 2010, Schulze et al, 2011, whereas other studies also show beneficial effects on the recognition of fearful faces (Fischer-Shofty et al, 2010). Some studies indicate that OXT promotes the identification of emotions regardless of valence (Lischke et al, 2012a;Prehn et al, 2013).…”

“…Furthermore, better emotion recognition after OXT administration is associated with increased pupil dilation, suggesting that OXT promotes the allocation of attentional resources during processing of emotionally salient facial expressions (Prehn et al, 2013). The assumption that OXT enhances the salience of social cues also gains considerable support from animal studies.…”

Oxytocin Attenuates Neural Reactivity to Masked Threat Cues from the Eyes

“…For example, intranasal oxytocin enhances covert attention to happy faces (Domes et al, 2013b) and facilitates attentional disengagement from masked angry faces (Ellenbogen et al, 2012). Furthermore, oxytocin improves recognition of dynamic facial expressions at lower intensity levels (Lischke et al, 2012;Prehn et al, 2013), increases sensitivity to implicit and unattended emotional face cues (Leknes et al, 2013), and enhances discrimination of masked facial emotions (Schulze et al, 2011). Together, these results suggest that oxytocin influences facial emotion processing at very early stages of stimulus perception.…”