Science has a knack for creating lengthy, complex names. Take prosopometamorphopsia, or PMO for short—this condition is quite rare, as noted by neuroscientist Dr. Austin Lim, who recently discussed it in an interview. Essentially, PMO causes individuals to perceive other people’s faces as they progressively morph into different, face-like forms.
Dr. Lim elaborates on this unusual neurological condition in his recent book, Horror On The Brain. It’s not something that happens instantly. A person might initially look at a normal face only to see it shift and transform, which can be quite perplexing given that their overall vision might still be normal. The condition can affect the perception of a whole face or just parts of it.
A particular case from 2020 described a patient, referenced as AD, who complained about faces appearing to melt on one side, a phenomenon that significantly impacted his daily life. To investigate this, researchers showed him various images of faces and objects in differing angles and perspectives. Notably, AD was able to recognize inanimate objects without issue, but faces were consistently distorted for him, no matter how they were presented.
The type of PMO AD experienced is termed hemi-prosopometamorphopsia, or hemi-PMO, which has only been documented 25 times in medical history when his case study was shared. It usually stems from some form of brain damage, and, in AD’s instance, was linked to a lesion in the splenium, an area associated with visual processing.
The core issue with PMO seems to resemble how facial recognition technology operates. When encountering a new face, we draw from a mental library of previously seen faces. For AD, a malfunction in the brain region tasked with this integration led to his perception of faces resembling something out of a Salvador Dalí painting.
PMO is also commonly referred to as “demon face syndrome,” which definitely captures the essence of what it involves. A paper published in 2024 was the first to visualize how individuals with PMO perceive faces, and the findings are quite unsettling.
At the time of that publication, about 75 cases of PMO had been reported. Even though much remains unclear, this demonic distortion appears to be a recurrent theme among some cases. Understanding its effects is important, as it can be mistaken for other conditions, like schizophrenia, which might lead to inappropriate treatments if the underlying visual system issues are overlooked.
Interestingly, those with PMO don’t only see faces morphing into gruesome forms. Dr. Lim mentions bizarre reports in his book, including faces resembling glued-together features, witches, melting zombies, and even one instance where a woman observed ordinary faces shifting into a dragon’s visage.
“There was a case described by Oliver Sacks, one of my favorite science writers,” Dr. Lim recounts. “In this case, if a woman stared at someone’s face for long enough, it would start morphing into a dragon—skin changing colors, often to shades of purple, developing scales, and ears becoming pointier. The perceptual changes were just astonishing.”
It’s really remarkable to think about what can happen when our brains start processing things differently.
