Long misdiagnosed as schizophrenia, the details of what a patient actually sees when suffering from “demon face syndrome,” or prosopometamorphopsia (PMO), have long remained a mystery – until today.
Only about 75 cases have been documented of this syndrome, in which a person perceives unusual, often grotesque distortions when looking at a human face.
But one rare individual 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, although he has seen “demon faces” more often. strange in his real life.
This split allowed him and the researchers to reliably illustrate, for the first time, what the faces of a person living with the haunting vision of PMO may look like.
“Most articles on PMO were brief reports on individual cases,” Dartmouth professor. Brad Duchaine told DailyMail.com, “written by the neurologists who encountered them in their clinical practice.”
“Our report is particularly interesting,” he said, “because … we can be sure that the distortions in 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, even though they see stranger “demonic faces” in their real life. This divide allowed researchers to properly illustrate, for the first time, what the faces of a person living with the demon-tinted glasses of prosopometamorphopsia (PMO) look like.
The damage that led to PMO often appeared as lesions on the occipital and temporal lobes at the back of the brain, near areas that neuroscientists have classified as face recognition areas, marked in green above . But some mysterious cases are more difficult to trace
“It is not uncommon for people with PDO not to tell others about their face perception problem,” Duchaine, co-author of the new study, said in a statement.
“They worry that others will think these distortions are a sign of a psychiatric disorder,” he added. “It’s a problem that people often don’t understand.”
Duchaine and Antônio Mellon, a doctoral student at Dartmouth, put their 58-year-old patient in the Prime Minister’s Office through a series of tests reminiscent of modern-day “police cartoonists.”
The researchers, who work with Dartmouth Social perception laboratoryfirst took a photo of a volunteer participant’s face.
They then showed this photo on a computer screen to the case study patient, asking him to look at that same participant’s real face and provide feedback on the differences he perceived.
“The distortions he sees,” Professor Brad Duchaine (above) told DailyMail.com, “provide a beautiful illustration of the fact that we don’t have access to the world. Instead, all of our experiences are constructed by the brain.
With real-time feedback from their 58-year-old, Mellon and Duchaine used computer software to adjust the volunteer participant’s photo to match how his condition in the PMO changed the faces he ‘He saw.
Their results, published today in a medical journal The Lancet, almost look like goblins – faces with pointy ears; pointed noses; and large reptilian mouths.
“The distortions he sees,” Duchaine told DailyMail.com by email, “provide a beautiful illustration of the fact that we don’t have access to the world.” Instead, all of our experiences are constructed by the brain.
Although the study represents a major step forward in understanding how this person with PMO sees the world, a comprehensive understanding of the disease is only beginning to emerge.
Visual distortions classified as PMO can vary considerably.
A 52-year-old woman, according to a previous study conducted in The Lancet, suffered all his life from seeing human faces transform into dragon faces. In another case, a 44-year-old woman describe seeing faces that “almost look like a caricature.”
“The distortions in the vast majority of PMO cases in the literature began after an obvious neurological event and almost all of those who were scanned had brain damage in the visual regions of the brain,” Duchaine told DailyMail.com.
The damage often appeared as lesions on the occipital and temporal lobes, near areas that neuroscientists have classified as face recognition areas.
But, as its Social Perception Lab continues to search for new manifestations of the syndrome – with an open call for new candidates on their dedicated web page — the laboratory begins to discover even more mysterious cases.
“We get many people on our website who are unaware of a neurological event that coincided with the onset of their distortions,” he said.
“We’ve also heard from a handful of people who said they’ve suffered from distortions their entire lives and even two cases of family members who also experienced facial distortions.”
Psychologists and other clinicians have been aware of this condition since at least 1953, when a sympathetic neurologist first coined its fraught official name, “prosopometamorphopsia.”
“MacDonald Critchley, one of the giants of 20th-century British neurology, coined the term,” according to Duchaine.
“Interestingly, Critchley was prosopagnosic himself – 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 position of facial features.
In addition to the documented fact that PMO can occur suddenly, last a few days or several years, or in some cases arrive at birth as a lifelong problem, Duchaine noted that mental health professionals often have difficulty identifying it. correctly.
“Many people with PMO have told us that they have been diagnosed by psychiatrists as having schizophrenia and have taken antipsychotics,” Duchaine said, “when their condition is a visual system problem.”
