Each year, the Neural Correlate Society holds a contest among experts on perception and visual illusions. The top ten entries get selected by a panel, and the three best are then picked in an international gathering that I imagine as some sort of wizards convention. Here are are the winners.
1. The Dynamic Ebbinghaus
The Dynamic Ebbinghaus takes a classic, static size illusion and transforms it into a dynamic, moving display. A central circle, which stays the same size, appears to change size when it is surrounded by a set of circles that grow and shrink over time. Interestingly, this effect is relatively weak when looking directly at a stationary central circle. But if you look away from the central circle or move your eyes, or if the entire stimulus move across the screen, then the illusory effect is surprisingly strong -- at least twice as large as the classic, static Ebbinghaus illusion.
Christopher D. Blair, Gideon P. Caplovitz, and Ryan E.B. MruczekUniversity of Nevada Reno, USA, USA
2. Flexible colours
One coloured image can lead to several colour perceptions, depending on the position of black outlines that are presented on top of the coloured image. The shape of a surface depends more on changes of luminance in the visual scene than on specific colours themselves. By presenting black outlines on top of coloured images, the whole area between outlines is seen as having one single colour. Instead of seeing the actual colours presented at each location, our brain prefers to see one homogenous colour, as surfaces in real life are usually also perceived with one single colour.
By Mark Vergeer, Stuart Anstis, and Rob van Lier
3. A Turn in the Road
By Kimberley D. Orsten and James R. Pomerantz, Rice University, Houston, TX, USA
The Neural Correlate Society is "an organisation that promotes scientific research into the neural correlates of sensory perception, awareness, and cognitive experience." According to their site, "the contest is a celebration of the ingenuity and creativity of the world's premier visual illusion research community. Visual illusions are those perceptual experiences that do not match the physical reality. Our perception of the outside world is generated indirectly by brain mechanisms, and so all visual perception is illusory to some extent. The study of visual illusions is therefore of critical importance to the understanding of the basic mechanisms of sensory perception, as well as to cure many diseases of the visual system. The visual illusion community includes visual scientists, ophthalmologists, neurologists, and visual artists that use a variety of methods to help discover the neural underpinnings of visual illusory perception."
In other words: They are just trying to screw our minds -- and succeeded.