The above optical illusion is in the form of a GIF. Click the image to see it animate, and then blink really fast. You’ll see Mandalas appear all over the place.
Mandalas, incidentally, are shapes of particular spiritual importance in Hindu and Buddhism. Yes, Wikipedia is the Internet citizen’s friend.
Whenever awards are given from criteria that aren’t quantitative, it’s pretty easy to question their validity. The above illusion won the Best Illusion of The Year 2007 as sponsored by the Neural Correlate Society, and while it’s interesting, perhaps 2007 was just a slow year. Still, this is what was said:
These images of the Leaning Tower are actually identical, but the tower on the right looks more lopsided because the human visual system treats the two images as one scene. Our brains have learned that two tall objects in our view will usually rise at the same angle but converge toward the top—think of standing at the base of neighboring skyscrapers. Because these towers are parallel, they do not converge, so the visual system thinks they must be rising at different angles.
These optical illusions were discovered at Harvard, and demonstrate a phenomenon they’re calling silencing:
Play the movie while looking at the small white speck in the center of the ring. At first, the ring is motionless and it’s easy to tell that the dots are changing color. When the ring begins to rotate, the dots suddenly appear to stop changing. But in reality they are changing the entire time. Take a look.
SILENCING demonstrates the tight coupling of motion and object appearance. Simply by changing the retinotopic coordinates—moving the object or the eyes—it is possible to silence awareness of visual change, causing objects that had once been obviously dynamic to suddenly appear static.
Well the above is pretty self explanatory, just look at it and you should see it pulsating somewhat. Click on it for a larger version and stronger effect.
We’re not sure what’s causing the illusion, but suspect it has something to do with your eyes’ microsaccades, the small, jerk-like, involuntary eye movements we all experience but usually don’t notice.
You’ve probably seen the above girl in those stupid ads that ask you “Are you right brained or left brained?” Or some such idiocy. But most people had a really hard time seeing the illusion. The above interpretation makes that easier. Look at the girl on the right, then on the left and hopefully you’ll notice the middle one changing directions. It doesn’t always work, but when it does it’s pretty awesome.
Look at the red dot. Then look at the green dot. Notice something? If your eyes are working right, you should notice the rotation of the rings change directions every time. This illusion uses the fact that vision is different at the fovea (the center of the retina and point of sharpest vision) and at the periphery. Here comes the science:
There are two sources of information.
The global motion rotates counter-clockwise; the internal motion rotates clockwise.
Your visual system has to “choose” how to perceive these conflicting sources of information. In other words, will perception be guided by the motion of the ovals? Or by the motion of the internal lines? Or by a combination of these two? Or will you be able to see both types of motion at the same time, while keeping their signals separate?
When you look directly at the one-ring display, you can discern both sources of information (the ring will spin one way, and the motion caused by the internal lines goes the other way). But when you look at this display peripherally, it becomes difficult to separate the two sources of information, and the internal motion drives the perceived direction of the ring.
We hypothesized that the machinery of the foveal visual system allows us to represent multiple features simultaneously, but this machinery is absent in the periphery. The peripheral visual system seems to mix up the features that are available in the scene.
The above illusion is the courtesy of Arthur Shapiro, Associate Professor, Department of Psychology, American University in Washington DC.