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• Posted March 22, 2024

Rare Condition Makes Others' Faces Appear 'Demonic'

Some people diagnosed with schizophrenia might instead be suffering from a rare visual condition that can cause other people's faces to appear “demonic,” a new study argues.

The condition, called prosopometamorphopsia (PMO), can cause others' facial features to appear horrific -- drooped, larger, smaller, out of position or stretched in disturbing ways.

“Not surprisingly, people with prosopometamorphopsia often find it disturbing to look at other people's faces,” researchers said on their website on the condition. “Fortunately, most cases last only a few days or weeks, but some cases perceive distortions in faces for years.”

Unfortunately, this disorder in vision has led to a diagnosis of mental illness in some patients. 

"We've heard from multiple people with PMO that they have been diagnosed by psychiatrists as having schizophrenia and put on anti-psychotics, when their condition is a problem with the visual system," said senior study author Brad Duchaine, a professor of psychological and brain sciences and principal investigator of the Social Perception Lab at Dartmouth University.

To help people understand PMO, Duchaine and his colleagues have produced the first case report to provide accurate and photorealistic examples of the facial distortions experienced by a specific patient with PMO.

The patient, a 58-year-old man, sees faces without any distortions if they're on a screen or on paper.

But when he sees someone in person, their face appears demonic and twisted, researchers said.

This provided a unique opportunity to see the world through the eyes of someone with PMO, since these patients usually see distortions in all faces, whether they're presented in photos or in person, said lead study author Antonio Mello, a doctoral student of psychology and brain sciences at Dartmouth University.

"In other studies of the condition, patients with PMO are unable to assess how accurately a visualization of their distortions represents what they see because the visualization itself also depicts a face, so the patients will perceive distortions on it, too,” Mello explained in a university news release.

The research team took a picture of a person's face, then had the patient compare that photo -- displayed on a computer screen -- to what he was seeing in person.

Using real-time feedback from the patient, the researchers then modified the photo to match the facial distortions seen by the patient.

Published March 20 in The Lancet journal, the finished product displays an average male face twisted into that of a goblin, with long slanted eyes, a leering grin, pointed ears and furrowed brow.

The researchers hope the images will increase understanding of PMO and how it can affect people with the condition.

"It's not uncommon for people who have PMO to not tell others about their problem with face perception because they fear others will think the distortions are a sign of a psychiatric disorder," Duchaine said. "It's a problem that people often don't understand."

However, they added that the condition is quite rare, with only around 80 case reports ever published on people suffering from PMO.

It's not clear what causes people to develop PMO, researchers said on their website. They speculate that the condition could be caused by abnormalities in either the brain regions used to process faces or the connections between those regions. 

More information

The American Academy of Neurology has more on prosopometamorphopsia.

SOURCE: Dartmouth University, news release, March 21, 2024