Long misdiagnosed as schizophrenia, the details of what a patient actually sees while suffering from ‘demon face syndrome’ or prosopometamorphopsia (PMO) have long remained a mystery – until now.
Only about 75 cases have ever been documented of the syndrome, in which a person perceives unusual, often grotesque distortions when staring at a human face.
But a rare person with the condition, a 58-year-old man who contacted neuropsychologists at Dartmouth, has the unique ability to see faces normally on paper and on screens, despite having seen more creepy ‘demon faces’ in his real life .
This split allowed him and the researchers to reliably illustrate for the first time what faces might look like to someone living with the terrifying vision of PMO.
“Most articles on PMO are short case reports on individual cases,” says the Dartmouth professor Brad Duchaine told DailyMail.com, “written by the neurologists they happened to encounter in their clinical practice.”
“Our report is especially interesting,” he said, “because … we can be confident that the distortions of his visualizations accurately reflect what he experiences.”
A rare individual with a variant of ‘demon face syndrome’ has the unique ability to see faces normally on paper and on screens, despite having seen more creepy ‘demon faces’ in his real life. The gap allowed researchers for the first time to properly illustrate what faces look like to a person living with the demon-tinted glasses of prosopometamorphopsia (PMO).
Damage leading to PMO was often found in the form of lesions on the occipital and temporal lobes at the back of the brain, near areas that neuroscientists have classified as face-recognition areas, indicated in green above. But some mysterious cases are harder to trace
“It is not unusual for people with PMO not to tell others about their problem with face perception,” Duchaine, co-author of the new study, said in a statement.
“They fear that others will think the distortions are a sign of a psychiatric disorder,” he added. “It’s a problem that people often don’t understand.”
Duchaine and Dartmouth PhD student Antônio Mellon put their 58-year-old PMO patient through a series of tests that resembled modern-day “police sketch artists.”
The researchers, who work with Dartmouth Social Perception Labfirst took a photo of a volunteer participant’s face.
They then showed their case study patient that photo on a computer screen, asking him to stare at the real face of that same participant and give him feedback on the differences he observed.
“The distortions he observes,” Prof. Brad Duchaine (above) told DailyMail.com, “provide a nice illustration that we don’t have access to the world. Instead, all our experiences are constructed by the brain’
Using real-time feedback from their 58-year-old, Mellon and Duchaine used computer software to adjust the volunteer participant’s photo to reflect the way his PMO condition changed the faces he saw.
Their results were published today in the medical journal The Lancet, look almost goblin-like – faces with pointy ears; sharp noses; and wide, reptilian mouths.
“The distortions he observes,” Duchaine told DailyMail.com via email, “provide a nice illustration that we have no access to the world. Instead, all our experiences are constructed by the brain.”
While the study represents a breakthrough in understanding how this one person with PMO sees the world, a broad understanding of the condition is only beginning to emerge.
The visual distortions classified as PMO can vary widely.
A 52-year-old woman, according to a previous investigation in The Lancet, has suffered her entire life seeing human faces turn into dragon-like faces. In another case, it involved a 44-year-old woman described seeing faces that “almost look like a caricature.”
‘Distortions in the vast majority of PMO cases in the literature started after an overt neurological event and almost everyone scanned had brain damage in the visual parts of the brain,’ Duchaine told DailyMail.com.
The damage was often found in the form of lesions on the occipital and temporal lobes, near areas that neuroscientists have classified as face-recognition areas.
But because his Social Perception Lab has continued to look for new expressions of the syndrome – with an open call for new candidates their special web page – the laboratory begins to discover even more mysterious cases.
“We hear from many people through our website who are unaware of a neurological event that coincided with the onset of their deformities,” he said.
‘We have also heard from a handful of people who report having had disfigurements throughout their lives, and even two cases where family members have also suffered from disfigurements.’
Psychologists and other physicians have been aware of the condition since 1953, when a sympathetic neurologist first coined the cumbersome official name “prosopometamorphopsia.”
“MacDonald Critchley, one of the giants of 20th-century British neurology, coined the term,” Duchaine said.
‘Interestingly, Critchley himself was prosopagnosic: he had great difficulty recognizing facial identity.’
The name is derived from the Greek word for face, ‘prosopon’, and a pre-existing medical term for perceptual or vision-based distortions ‘metamorphopsia.’
The variation in symptoms includes not only shapes and sizes, but also colors and even positions of facial features.
Along with the documented fact that PMO can occur suddenly, last only a few days or many years, or in some cases be a lifelong problem from birth, Duchaine noted that mental health professionals have often struggled to diagnose it correctly. identify.
“We have heard from several people with PMO that psychiatrists have diagnosed them with schizophrenia and put them on antipsychotic medications,” Duchaine said, “even though their condition is a problem with the visual system.”