Flashed face distortion

[Bonnie]

Tangen, Murphy, and Thompson just published an article on this effect in Perception (40: 628-630, 2011).

They report that

We standardised the presentation rate and found that roughly 4-5 faces per second was ideal [for producing the effect]. After gazing at a continuous sequence for a minute or so, many of the faces will appear highly distorted, even monstrous. The degree of distortion is greatest for faces that deviate from the others in the set on a particular dimension. If one face has an especially large or pronounced forehead compared to the others in the set, for example, then it appears particularly bulbous.

Relative encoding seems to drive the effect. That is, forcing the observer to encode each face in light of the others. By [the investigators'] eye-aligning the faces, it becomes much easier [for the observer] to compare their shape and the relative location of their features, so the differences between them become more evident. The fast, steady presentation rate may also encourage this relative encoding. If the faces are not eye-aligned or if they are presented too slowly or quickly, then the effect lessens. Or, if we insert a brief gap in the sequence, the effect almost completely disappears.

-- Bonnie

[Lainie]

Originally Posted by Singing in the Drizzle

I would say it has more to do with peripheral vision and how the eye processes that information.

I saw little to no distortion, and I test well for peripheral vision.

OTOH, that depth perception test where you have to identify which of a group of dots stands out from the background? I'm really bad at that.

[TrishDaDish]

While you're tripping out, why not make your eyes think you're underwater?

[Diabolus Ex Deus]

I really couldn't see much other than some skin-tone mixing, but my co-worker was floored by the effect. Really interesting how that is.

[jayjaybear]

Originally Posted by TrishDaDish

While you're tripping out, why not make your eyes think you're underwater?

That was just...disturbing. It looked like everything was BREATHING!

As far as the original optical illusion, I thought quite a few of those faces ended up looking like the Forsaken in World of Warcraft.

[thorny locust]

I watched it through following the instructions, focusing on the cross in the middle. Then I watched it once more covering the left face with my hand and looking directly at the right one; and again covering the right face and looking directly at the left one.

I got the exact same effect all three times: as the faces changed from one face to the next, there was a distortion effect during the change; for the moment inbetween, the faces looked normal. Unless there's something there I didn't see at all (which is certainly possible), it's got nothing to do with seeing two faces at once, or with peripheral vision; it's got to do with the rapid change from one face to another.

[RivkahChaya]

Even if you watch just one side, with both eyes, it looks cartoonish, although if you stop it, you see a normal face-- a photo, that it.

I think it's because the images are flashing so fast, they're coming at something like the rate of frames in a motion picture, so it looks like a "morph," rather than a series of discrete images.

Is it downloadable? I'd love to count the actual image-per-second rate, and slow it down. Once it was slowed to something I could perceive as a series of images, and not a moving picture (ie, "morph"), then I'd like to see whether the effect when looking at the + is still there.

I really don't think anything mysterious is happening. I think we're just seeing still images that are so rapid we're being tricked into perceiving them as moving, and in addition to that, we're seeing them peripherally, so discrimination is very poor, and we can't catch on to the trick.

Just as a note, modern films are standardized at 24 frames per second, but that's because early sound films required that speed for good sound quality with sound-on-film. You can see a moving picture from a series of still flashed at a much slower speed, and some old silents were as slow as 14 frames per second.

[missy_pooh_1997]

How strange. Alot of the people looked like they had giant eyes.

[Luka_the_Pooka]

Originally Posted by TrishDaDish

While you're tripping out, why not make your eyes think you're underwater?

The wall are bulging! And the dog looked like it had an Alien trying to get out!

[granola shoes]

Originally Posted by NorthernLite

That was just bizarre. I kept glancing over at the pictures to make sure it wasn't some trick but they all looked normal. And then when I looked back at the cross they all went creepy again. Weird.

That's the same experience I had. I kept seeing faces that appeared to be Sloth from the Goonies.