Grotesque Illusion

December 14, 2011 3:13 PM

Sean Murphy was looking at sets of faces for one of his experiments when he observed something really freaky. Skimming fairly rapidly through pictures of two faces side-by-side, Murphy started noticing that some of the people he had pictures of had grotesque and deformed faces. But when he looked at the pictures again, this time individually, they all looked normal. Watch the video to experience the Flashed Face Distortion Effect and make your brain creep you out.
posted by painquale (3 comments total)

Double, I think.
posted by rtha at 3:16 PM on December 14, 2011

I get the same effect if I cover up one of the faces and continue looking at the cross. It seems it's an effect of slower processing on the edge of the visual field--- and this is exacerbated to an extreme degree if there are two faces present.
posted by melatonic at 3:28 PM on December 14, 2011 [1 favorite]

I don't know if this even qualifies as an optical illusion. They're flashing each set of images so quickly that the brain can barely keep up and begins averaging out a given face to the image before it or after it. To facilitate this, they've lined all the faces up at the eyes, giving the impression that a static face is morphing in odd ways. And they seem to have intentionally juxtaposed faces that are at the extreme edges of normal. Big eyes get glommed onto an elongated chin, etc. It's difficult enough to keep each individual face coherent if you stare at one of the sides of the screen; when you put two sets in the periphery of your vision and stare at a center point, all you see are the points of deviation from the imaginary mean.

To put it another way, I don't know if this "illusion" would work if the faces weren't perfectly centered and if they didn't vary so dramatically from one another in the manner of their sequencing.
posted by R. Schlock at 3:29 PM on December 14, 2011