The Alien Faces Illusion explained with youtubers

I've recreated the Flashed Face Distortion Effect with well known youtubers and some of my favourites.

I also talk about some of the theories for how it works. Also in the video is the thatcher illusion and motion after effect.

Here are all the channels as they appear in order on the left hand side:

[glitterypieceofmind]

“... and some of my personal favorites”

*use picture of himself*

I see you!

[henrycgs]

that was actually kind of terrifying. some of them looked so distorted it was almost gorey

[matthewleiner]

@Steve Mould
As a thought after the alien faces demo, I tried watching the rest of the video by looking just off to the right of your face, and I found myself experiencing a more mild version of the same illusion.When you turned your head from slightly sideways to straight on at the camera, your eyes and head would expand as if to compensate for the growing distance between your eyes, and your pupils were easy to tell which direction they were pointed. When you would make an expressive eye or mouth gesture, those parts would grow/shrink or move around more drastically than when I rewatched the few seconds again looking directly on, maybe as my brain was showing me how your emotions were changing.
Perhaps this is some sort of evolutionary social advantage to being able to more easily pick up on when someone out of view changes their emotion towards you as if to warn or update you on your relative social position/change within others' minds. And it could be this way towards the periphery because - besides the fact that middle vision is more detailed - you would want to more easily pick up on general expression changes of onlookers staring at you, making you more quickly aware if you were doing something taboo when you were unknowing of the circumstances of your action prior to make emotional expression look more dramatic.

[sheck]

he really undersold this one.
I literally saw one guy who had just flat skin on his entire face down to his mouth, but instead of his mouth that's where his eyes were. another guy just had a big mouth in the middle of his face, but he looked pretty chill with that

[trdi]

Interesting subject. I have two things to add to this.

When I was a kid I used to see faces everywhere. Cars, trains, rocks, anything had a face. I'm not sure if that's unusual in any way or other children experienced the same.

The second thing is an experiment with true mirror. Yes, I spent 300 or 400 euros and bought a true mirror (they are expensive because they are not manufactured in big quantities, sucks), mirror that doesn't swap left and right side. This means that when I look in the true mirror, I see myself as others see me. It's a weird experience and very big majority of people dislike their image in true mirror. The reason why they dislike it is because they are used to the image they see in a normal mirror. Because 99% of all faces are NOT symmetrical, once we see ourselves in the true mirror we see all the differences from the "normal mirror image" intensified and as such they appear more grotesque. Example... let's say that your left eye is 2 millimeters closer to nose line. You get used to seeing that every day so when you see for the first time a mirror image where the difference is on the other side, it gets multiplied - you see it being 4 mm instead of just 2.

[FlyingJetpack]

You can actually test your theory of the fusiform face area being the main cause of the flash face disturtion effect.
There are people that have a disorder that is called Prosopagnosia, which makes them unable to recognize faces due to some form of damage that was done to the fusiform face area in the brain. Therefore, if your theory is correct, they shouldn't see the effect in action, and just see pictures of people flashing in the corner of their eyes.
But if they do experience this effect, then the main culprit would be the neural adaptation, or something else entirely.

I might be overlooking something here, but this sounds like a pretty effective way of testing your theory out.
These sort of people aren't THAT rare either, according to wikipedia, up to 2.5% people in the US experience it to some degree, so gathering a handful of people that are willing to look at this video shouldn't be impossible either.

[namename-mzje]

5:57 motion illusion starts. For people who want to retry it

[asainsan]

0:51
I love how James has the highest quality portrait out of them all

[gljames]

When those faces are upside down, they're creepily uncanny. Then when you turn them around it gets worse.

[biscuitsalive]

Genuinely think that tripped off a LSD flashback doing that “look at hand” thing!
Very disturbing. I need a cup of tea to recover.

[Mede_N]

I like this warping effect you use to avoid jump cuts. nice attention to detail!

[GuildOfCalamity]

This might be the best channel on Youtube.

[eddievanhorn]

3:05 "Looks normal upside down, but when you flip it, it looks more realistic."

[jaypaans]

I noticed the motion after effect years ago - when I was young. After riding on my bike (continuously) for a rather long time and then stopping on the side of the road, my surroundings (especially the road) seemed to move away from me.

[vampyricon]

I looked at the apple I was eating while staring at the moving stripes before Steve explained it and it was a pretty wtf moment.

[praveenb]

Civilized man has lost the ability to spot aliens posing as humans. By concentrating on the cross, we free up the subconscious mind and it's able to recognize alien faces again.

[Djjminijacko]

I found it more interesting to look at Steve after that illusion rather than my palm

[WyattCayer]

The most bizzare part of the thatcher illusion in my opinion is how she is looking at you when it's upside down but when you flip it appears as if she is staring down. I don't get how that part works.

[reganheath]

Ok, how about this for an alternate explanation. It's a bit like the first of the two explanations given, but not quite... Because you're not looking directly at the faces, your facial recognition algorithm is getting less detailed information about the faces, as it has to rely on peripheral vision. So to do it's job it's taking what gross measurements it can, in other words only the distances between facial features. When the face changes, it refuses to believe that is possible, so instead assumes the new features are in the same position to the old features and to maintain this has to distort (stretch or compress) what little information it has between the features.

[OliviaSNava]

When you introduced the upside down face with the flipped eyes and mouth, I *instantly* realized the eyes were upside down, but it wasn't until you flipped it that I saw the mouth was too. Weird how that happens.