Researchers who study the features of the perception of visual information by the human brain once a year allow themselves to escape from scientific work and participate in the Best Visual illusion of the Year contest. This is a competition where each of them can demonstrate their discoveries in practice. Here is a list of finalists and winners of the 2011 competition.

1st place. Disabling the perception of color changes due to the movement of the background

Description. If you look at a small white dot in the middle of the screen, you can clearly see the color change of the surrounding elements. If the surrounding elements begin to rotate, then the brain can not cope with the processing of information about the color change of each of them.


^{mp4 , webm , ogv , vimeo
Authors: Jordan Suchow, George Alvarez, Harvard University
Scientific work}

Other demonstrations of the same effect.

2nd place. Contrast grouping

Description. The brightness level of four discs changes over time. The top two darken simultaneously, while the bottom two darken simultaneously - and vice versa. Against a contrasting background, it seems that the disks are grouped diagonally, but after replacing the background, it can be seen that they are actually grouped horizontally.


^{Authors: Erica Dixon, Arthur Shapiro, Kai Hamburger, American University of Washington, University of Giessen (Germany)}

3rd place. Loch Ness aftereffect

Description. Concentrating on the red dot in the center, over time it seems that the surrounding gray lines slowly rotate in one direction, and then quickly scroll in the opposite direction. Reverse rotation is an illusion due to the after-effect of slow rotation.


^{Posted by Mark Wexler, Paris Descartes University}
Better version with rotation settings.

Finalist. Face morphing

Description. If you follow the red dot, then the change in facial features is hardly perceptible. If the red dot disappears, then it becomes obvious that a person changes the shape of his eyes, skin color and even sexual characteristics.


^{Authors: Rob van Lier, Arno Koning, Donders Institute (Netherlands)}

Finalist. Mask of love

Description. Looking at this Venetian mask, many observers cannot immediately understand that it actually consists of two people: a man and a woman kissing each other. When the brain recognizes two objects, it is able to stabilize on one or the other (the so-called "bistable illusion").


^{Authors: Gianni Sarconi (Gianni Sarcone), Courtney Smith (Courtney Smith), Mary-Joe Waber (Marie-Jo Waeber)}
Original image .