The Neural Correlate Society (NCS) has named the winners of its 2019 Best Illusion of the Year Contest, with the top prize going to a spinning structure that appears to be rotating along both axis, in both directions, all at once.
The Best Illusion of the Year Contest is a celebration of illusions and perception, created by the ingenuity of the world’s premier illusion creators.
Illusions are perceptual experiences that do not match the physical reality.
“How we see the outside world―our perception―is generated indirectly by brain mechanisms, and so all perception is illusory to some extent. The study of illusions is critical to how we understand sensory perception, and many ophthalmic and neurological diseases,” the NCS said.
Optical illusions draw the attention of visual scientists, ophthalmologists, neurologists, and artists, who use many different methods to discover the underpinnings of illusory perception.
The NCS is a US-based nonprofit organization that promotes scientific research into the neural correlates of perception and cognition, which includes representatives from several universities and medical centres.
The Best Illusions are selected by a panel of judges, who narrow down all submissions to the top 10, which are then voted on by the public.
These are the top three winners, along with the other seven illusions features in the top 10.
First place: Dual Axis Illusion
This illusion, designed by Frank Force, has a structure which appears to be spinning around a vertical axis – until you’re shown a horizontal axis, then it switches to spinning around that. If you stare long enough, it also then appears to start spinning in the opposite direction.
The trick to this illusion is that it will change depending on which cross-over or overlap of lines you focus on.
Second place: Change the colour
This illusion from the University of Tokyo’s Haruaka Fukuda allows you to change the colour of the dots in motion, by changing your perception of the direction they’re moving in.
If you view the dots moving from left to right, they all appear yellow. If you view them as moving from the bottom to the top, they appear green and red.
Third place: The Rotating Circle
The third-prize winner comes from Ryan Mruczek and Gideon Caplovitz from the College of the Holy Cross and University of Nevada Reno, USA.
In this illusion, the central black dot is always rotating on the same spot, in the same way – but motion introduced by other dots makes it appear as if it is moving in all other sorts of ways.
The rest of the top 10 are:
This physical illusion challenges the cognitive barrier between seeing your fingers as a part of yourself or as detached objects. Using a mirror and a small space to place your hand under, subjects see how “weird” it is experiencing their own fingers as something else entirely.
This physical illusion is of a bird facing right. But spinning it 180 degrees leaves it still facing right.
Using a dark filter (like sunglasses) over one eye, you can change the direction of the spinning helix. By squinting your eyes, you can make them appear to be moving up and down.
What appears to be a 3D box on a wall, is actually nothing like it. An example of how perspective and 3D distance affects how we see and experience the world.
Magic Tic Tac Toe
What appears to be a regular grid for a game of tic-tac-toe (naughts and crosses for us South Africans) actually hides the fact that the squares are a checker-board of light and dark teal. Our brains work in secret to balance out the differences for us.
The Chunder Thunder
In this illusion, the 17th Dutch marine artist Ludolf Bakhuizen’s painting “Ships on a Stormy Sea” appears to be in motion – but there is no movement happening.
Ambiguous Cardboard Arrows
Another physical illusion, where cardboard tubes cut in a certain way depict arrows pointing one way – and their mirror reflection pointing in the opposite direction.