The illusion: Mask of Love

(Image: Gianni Sarcone, Courtney Smith & Marie-Jo Waeber)

At first, it looks like a pensive face in a Venetian mask (see photo above) but take a closer look at its features and you'll see that it conceals a couple kissing.

Aptly named Mask of Love, the illusion was created by Gianni Sarcone, Courtney Smith and Marie-Jo Waeber from Archimedes' Laboratory in Genoa, Italy, after discovering the blurry photograph.

Optical Illusion: Ball in glass mystery

It's a simple set-up: a ball appears to be in a glass. But when a hand appears to pluck the ball out, you'll see that there's some trickery involved (see video above).

It's the latest illusion filmed by psychologist Richard Wiseman that ties into his new book, Paranormality: Why we see what isn't there. He assures us that the scene is not computer-generated and was filmed in a single continuous shot, without the use of editing tricks afterwards.

Floating Dice illusion

It may seem like an impossible construction. In this video, stacked-up dice seem to float on top of each other. They even appear to hover when viewed up close, until a hand appears on camera to reveal the visual trick. Were you fooled by the illusion?

This set-up, recreated by illusion fanatic Rex Young, is a classic devised by legendary illusionist Jerry Andrus. You may be familiar with the effect as it's one example of the hollow mask illusion.

When viewing a concave mask, most people perceive a convex face. It's our brain's most common interpretation of the visual information since we're so used to seeing people's everted faces.

The late British psychologist Richard Gregory studied the illusion and saw it as evidence for the top-down processing of visual information. Interestingly, a recent study found that people with schizophrenia are immune to the effect, raising the possibility that the illusion could be used as a diagnostic tool.

The dice arrangement was one of our favourite illustrations of this illusion, but we came across a lot of other examples. Have you seen a version of the effect that you find particularly effective? Let us know in the comments below.

Optical Illusion: The warped chessboard

Moving Wheel Illusion

Want to see an illusion that will get your cogs turning? In the video above, you can see three versions of a new illusion by Sung Ho-Kim at Rutgers University, New Jersey, that trick your brain into thinking circular patterns that shift across a screen are actually spinning. Make sure you are close to the screen to see the full effect.

In the first animation, the top and bottom halves of the shape should look like they are rotating in opposite directions. They switch directions as the motion of the pattern changes from left to right. In the second version of the illusion, a block covers half of the shape. This time it looks like the spokes of a wheel are rotating as the whole pattern travels left and right across the screen. In the final animation, two gears connected by a chain appear to be rotating together.

If you're convinced that these shapes are actually turning, try tracking each of the short lines, and you'll see that it's an illusion. The physical trajectory of each line segment is purely horizontal and none of the circles are rotating.

Optical illusions

Why do these two surfaces in the same shade of grey appear so different?

Optical illusions are more than just a bit of fun. Scientist Beau Lotto is finding out what tricking the brain reveals about how our minds work. Here he explains his findings.

Sight, hearing, taste, touch, smell. We believe what our senses tell us but most of all we trust our eyes.
But our brains are extraordinarily powerful organs.
Without us realising it, they are instantly processing the information they receive to make sense of the world around us.
And that has been crucial to our evolution.

More....

Optical Illusions are Fun

An animation that appears to have illusory contours was awarded second place in the contest. Created by Bart Anderson at the University of Sydney, Australia, it's made up of four circles and four dots that move back and forth over the outline of a rectangle. Contours connecting the moving dots in the middle seem to appear, creating a diamond that sometimes seems to morph into a more rounded shape as it stretches out.

Contours appear in many illusions. They can normally be explained by the way fragments of objects are arranged: a well-known shape without visible contours is inferred because our brains choose the most likely configuration based on the visual information.

But this explanation doesn't seem to apply to Anderson's illusion. The moving circles and dots are never partially obscured, so the brain shouldn't have to infer another shape. "This illusion can't be understood with any known mechanism that has been proposed to explain the formation of illusory contours," says Anderson.