A direct examination of the effect of intranasal administration of oxytocin on approach-avoidance motor responses to emotional stimuli.

Angeliki Theodoridou*, Ian S. Penton-Voak, Angela C. Rowe

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

36 Citations (Scopus)

Abstract

Oxytocin has been shown to promote a host of social behaviors in humans but the exact mechanisms by which it exerts its effects are unspecified. One prominent theory suggests that oxytocin increases approach and decreases avoidance to social stimuli. Another dominant theory posits that oxytocin increases the salience of social stimuli. Herein, we report a direct test of these hypotheses. In a double-blind, placebo-controlled study we examined approach-avoidance motor responses to social and non-social emotional stimuli. One hundred and twenty participants self-administered either 24 IU oxytocin or placebo and moved a lever toward or away from pictures of faces depicting emotional expressions or from natural scenes appearing before them on a computer screen. Lever movements toward stimuli decreased and movements away increased stimuli size producing the illusion that stimuli moved away from or approached participants. Reaction time data were recorded. The task produced the effects that were anticipated on the basis of the approach-avoidance literature in relation to emotional stimuli, yet the anticipated speeded approach and slowed avoidance responses to emotional faces by the oxytocin group were not observed. Interestingly, the oxytocin treatment group was faster to approach and avoid faces depicting disgust relative to the placebo group, suggesting a salience of disgust for the former group. Results also showed that within the oxytocin group women's reaction times to all emotional faces were faster than those of men, suggesting sex specific effects of oxytocin. The present findings provide the first direct evidence that intranasal oxytocin administration does not enhance approach/avoidance to social stimuli and does not exert a stronger effect on social vs. non-social stimuli in the context of processing of emotional expressions and scenes. Instead, our data suggest that oxytocin administration increases the salience of certain social stimuli and point to a possible role for oxytocin in behavioral prophylaxis.

Original languageEnglish
Article number58113
Number of pages6
JournalPLoS ONE
Volume8
Issue number2
DOIs
Publication statusPublished - 28 Feb 2013

Structured keywords

  • Cognitive Science
  • Social Cognition

Keywords

  • FACIAL EXPRESSIONS
  • AUTOMATIC EVALUATION
  • ARM FLEXION
  • FACES
  • HUMANS
  • AMYGDALA
  • RECOGNITION
  • BEHAVIOR
  • FEAR
  • NEUROPEPTIDES

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