The Influence of Reward on Facial Mimicry: No Evidence for a Significant Effect of Oxytocin
Lebenswissenschaftliche Fakultät
Recent findings suggest a role of oxytocin on the tendency to spontaneously mimic
the emotional facial expressions of others. Oxytocin-related increases of facial mimicry,
however, seem to be dependent on contextual factors. Given previous literature showing
that people preferentially mimic emotional expressions of individuals associated with high
(vs. low) rewards, we examined whether the reward value of the mimicked agent is
one factor influencing the oxytocin effects on facial mimicry. To test this hypothesis,
60 male adults received 24 IU of either intranasal oxytocin or placebo in a double-blind,
between-subject experiment. Next, the value of male neutral faces was manipulated
using an associative learning task with monetary rewards. After the reward associations
were learned, participants watched videos of the same faces displaying happy and
angry expressions. Facial reactions to the emotional expressions were measured with
electromyography.We found that participants judged as more pleasant the face identities
associated with high reward values than with low reward values. However, happy
expressions by low rewarding faces were more spontaneously mimicked than high
rewarding faces. Contrary to our expectations, we did not find a significant direct effect of intranasal oxytocin on facial mimicry, nor on the reward-driven modulation of mimicry. Our results support the notion that mimicry is a complex process that depends on contextual factors, but failed to provide conclusive evidence of a role of oxytocin on the modulation of facial mimicry.
Notes
This article was supported by the German Research Foundation (DFG) and the Open Access Publication Fund of Humboldt-Universität zu Berlin.