Revealed masks: Facial mimicry after oxytocin administration in forensic psychopathic patients

What Was Tested

The paper reports a study of Oxytocin, published as a randomized controlled trial.

Facial mimicry serves as an evolutionarily rooted important interpersonal communication process that touches on the concepts of socialization and empathy.

Facial electromyography (EMG) of the corrugator muscle and the zygomaticus muscle was recorded while male forensic psychopathic patients and controls watched morphed angry or happy facial expressions.

Who Took Part

According to the abstract, 20 patients were involved.

By PubMed's age tags, the people studied were young adults and adults, men only.

How the Study Was Run

In design terms this was a randomized, placebo-controlled and crossover study.

Random assignment meant chance, not the researchers, decided who got Oxytocin and who got the comparison, which limits bias.

A placebo (an inactive look-alike) gave the Oxytocin group a baseline to be compared against.

In the crossover set-up each of the patients took both Oxytocin and the comparison in turn, acting as their own control.

What Was Measured

The researchers tested the hypothesis that psychopathic patients would show weaker short latency facial mimicry (that is, within 600 ms after stimulus onset) than controls.

Exclusively in the group of 20 psychopathic patients, the researchers tested in a placebo-controlled crossover within-subject design the hypothesis that oxytocin would enhance short-latency facial mimicry.

The subject headings attached to it are Oxytocin, Facial Expression, Electromyography, Antisocial Personality Disorder, Facial Muscles, Emotions and Imitative Behavior.

What This Means in Plain Language

The paper is a randomized, placebo-controlled and crossover study of Oxytocin in 20 patients.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 2024 (Journal of psychiatric research), a journal based in England.

More context: the Oxytocin compound page, all human trials.