Friday, October 26, 2018

'Facephenes': Hallucinations of faces, stimulated in the lab

Images courtesy Schalk and Discover Magazine
Facephenes are hallucinations of faces caused by stimulation of the face-recognition area of the brain.


Link to Video on YouTube
The patient was a epileptic Japanese man outfitted with a large number of brain electrodes to find the source of his seizures. He described the experience: "Your face changed completely," he said. “I don’t know what’s going on. Your eyes…change.” Sometimes parts of faces emerged, and at weird angles, and other times an anime-like character appeared over the background object.

It appears that facial recognition skills in the brain are primarily situated in the lower, lateral areas of the brain, right next to areas that play an important role in color perception, so when the stimulation moved over a bit, rainbows instead of faces appeared.

From the researchers notes to the YouTube video:

"The human brain handles several mental processes and cognitive tasks like the visual perception of the environment. Many studies investigated the role of individual brain regions during dedicated mental processes and tried to understand whether a specific brain region is exclusively engaged in such a process. In a recent study we partly answered that question by electrically stimulating the ventral temporal brain of a patient who underwent surgical treatment of epilepsy. Electrical stimulation of color- and face-selective sites, which were identified by means of visual evoked responses in the brain waves, affected only color and face percepts, respectively. The reported symptoms included illusory faces on top of objects and changed perception of faces during stimulation of face-selective regions, and the appearance of illusory rainbows near color-preferring sites. These findings support the theory that the brain at least partly consists of specialized regions that are exclusively and causally engaged in a dedicated mental process."

A key question posed by Neuroskeptic is whether the faces seem "superimposed over" the objects, or whether the objects appear to have the faces integrated into their forms. If they ever try an experiment like this on an artist, they'll get a much clearer description of the experience. 

Discover Magazine “Facephenes”: Brain Stimulation Creates Phantasmal Faces
IFL Science: Brain Stimulation Causes Man to See Ghostly Cartoon Faces Everywhere
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Today, October 26, is the last day of the "American Masters" exhibition in New York City
I'll be giving a talk in Austin, Texas on Monday. Open to the public, but reserve your spot.

4 comments:

Roberto Quintana said...

This is very interesting, though not surprising, that stimulating a region in the brain associated w face recognition would cause face hallucinations.
It’s not even that surprising that the Japanese subject describes part of the illusion as “anime-like.”
I agree w Neuroskeptic : “If they ever try an experiment like this on an artist, they'll get a much clearer description of the experience.”

A portrait artist or animator would be very interesting!

I am really curious if the rainbow effects are really that of a ‘rainbow’ (refracted light w a full color spectrum) or just colorful flashes or colored ‘Auras’. -RQ

Amanda said...

Wow, that must be the part of my brain that doesn't work properly. I wonder if getting it stimulated like that experiment would fix it? It's become socially isolating because people think I'm snubbing them when I don't recognise them. No problem if they speak or I get a glimpse of gait, it's just faces. If anyone is looking for an artist to volunteer, my hand is in the air!

Roberto Quintana said...

@Amanda:
This reminds me of Chuck Close.
Incredibly, in addition to having suffered a debilitating stroke that left him a quadriplegic, He also has ‘Prosopagnosia’ or face blindness! Talk about perseverance!! -RQ
Check out this google-search:

https://www.google.com/search?q=chuch+close+face+recognition&oq=chuch+close+face+recognition&aqs=chrome..69i57.29343j0j8&sourceid=chrome&ie=UTF-8

Muddy Colors said...

Geez, our brains are amazing! Thanks for sharing, James.