To prevent getting lost, the elevator goes directly to the safety island to report Liu Yadong A
Source: Global Science
Author: Shi Xiaozhou (compiler)
图片来源:A. Mello et al., The Lancet, 2024
Wake up and have nightmares.
We often take for granted that what we see as others is who they really are. However, there is a part of the population that has a distorted perception of the face.
Veronica Smith looked at her partner's face and suddenly noticed a change in his facial features: his eyes were close and apart, his chin was wide and narrow, his skin was moving, even glistening. This phenomenon is not uncommon for Smith, 32, who has been experiencing it since she was four or five years old. This phenomenon comes and goes when she looks at other people's faces, and more persistent when she looks at her own faces.
Smith suffers from an extremely rare condition called prosopometamorphopsia (PMO). In the patient's eyes, the shape, texture, position, or color of the face may be distorted. Brad Duchaine, a professor of psychology and brain science at Dartmouth College in the United States, explains that some patients see a distortion of the entire face (bilateral PMO), while others only see a distortion of the left or right side of the face (unilateral PMO).
Image credit: pixabay
In the past, it was thought that PMO was a form of propatophosia, or "face blindness". But it is now increasingly clear to scientists that the two diseases do not occur with each other, and that the pathogenesis overlaps only a small part. Today, scientists believe that PMO is a visual distortion and is one of more than 40 "Alice in Wonderland syndromes," which often distort a person's perception, making people or objects appear larger or smaller than they actually are.
"In the last century, only about 75 cases of PMO have been reported in the literature. We know very little about this disease because these cases are often recorded by neuroscientists who have neither the expertise in optic neuroscience nor the time to delve into these cases." Jan Dirk Blom, a professor of clinical psychopathology at Leiden University in the Netherlands, believes that research on PMO is important because it may help scientists find clues to the areas of the brain responsible for facial representation.
Many patients with PMO (e.g., Smith) will see facial features distorted, while others will see the face droop or distort, skin texture become like tree bark, facial features become geometric, or a face superimposed on many people. In some cases, a person's face may even look like a demon.
Image credit: pixabay
Most PMO patients perceive facial distortion whether they look at a real face or a photo of a face. However, a recent study published in The Lancet described a highly unusual case: a 58-year-old male patient had no abnormalities when he looked at a face on a screen or on a piece of paper, and only when he saw someone in person did the face become demonic. In order to reproduce the patient's face, the researchers showed him a photograph of the face on a computer screen, while also having the person in the photo stand in the room. The researchers asked the patient to describe the difference between the photo and the real person, and gradually modified the photo until the patient felt that the photo matched the real face in his eyes.
Smith, who has long suffered from migraines, said she has seen more frequent and intense facial distortions this year, followed by an equally higher frequency of migraines. This suggests that migraine may be associated with PMO. But so far, researchers don't know the exact cause of PMO, only that migraines, epilepsy, eye and brain lesions, among others, may be involved. Similarly, there is currently no proven treatment for PMO.
People with PMO are often diagnosed with mental illnesses, such as schizophrenia, so medications prescribed by doctors are often used to treat mental illness, even if the real problem is the visual system, Dischena said. Psychoactive drugs, such as selective serotonin reuptake inhibitors (SSRIs), have been used to treat PMO, but have had little success. It's important to note that short-term facial distortions usually improve on their own, so it's hard to determine if this is the effect of the medication.
Blom explained that clinically, brain magnetic resonance imaging, EEG and blood tests can be used to try to identify the different factors behind PMO so that appropriate drugs can be used.
Image credit: pixabay
In April, Dichener co-authored a review that uses PMO to illustrate the basic theories of facial representation, including whether our perception and judgment of faces depend on the same way the brain represents them, what the nature of facial symmetry is, and how the visual system separates the two halves of the face.
In 2021, Di Xena set up a website specifically for PMOs. To date, he has been contacted by 60 patients describing their PMO symptoms. Only a small percentage of them were able to pinpoint that an event was responsible for their distorted facial perception. Dischena argues that there could be two explanations for this discrepancy. One is that many patients have brain damage that needs to be detected by brain scans, and the other is that many patients have no brain damage and that Dichener's research is not limited to people who have suffered neurological damage, so they were discovered.
Some patients develop PMO at a young age, possibly because they have problems with the development of their facial perception mechanisms, Dichena said. He and his team's ongoing research shows that distortions of facial perception in many cases can be mitigated by manipulating the appearance of the face in their eyes, such as changing color. For example, when Smith wore orange glasses, her symptoms were alleviated.
Wearing "tinted glasses" is just one way scientists manipulate the brain's input signals. In other studies, scientists have been able to give specific stimuli to boost brain function while people are asleep.
Reference Links:
https://www.scientificamerican.com/article/a-rare-visual-disorder-twists-faces-out-of-shape1
https://gizmodo.com/haunting-distorted-demon-faces-rare-syndrome-insights-1851355281
https://medicalxpress.com/news/2024-03-visualizes-demonic-distortions-case-prosopometamorphopsia.html
https://www.iflscience.com/does-every-face-look-demonic-to-you-then-you-might-have-this-super-rare-condition-73500
https://www.smithsonianmag.com/smart-news/this-extremely-rare-neurological-condition-makes-faces-appear-distorted-or-like-a-demon-180984015/
https://www.sciencealert.com/seeing-demons-mans-rare-brain-condition-transforms-faces-into-monsters
This article is from the WeChat public account "Global Science" (ID: huanqiukexue), if you need to reprint, please contact [email protected]