The Best Illusions of 2020

This year marks the 16th edition of the Best Illusion of the Year Contest, hosted by the Neural Correlate Society since 2005. In the contest, cognitive scientists and visual artists from around the world submit cutting-edge illusions to be evaluated by judges and spectators. Past winners of the contest have gone on to viral fame, such as the Flashed Face Distortion in which normal faces presented in the visual periphery appear grotesquely distorted, and the Break of the Curveball in which a spinning ball that's moving in a straight path appears to permanently curve its path to one side.

Each year, a panel of judges narrows down dozens of illusion entries from around the world to the top 10 finalists based on five factors: (1) their significance to our understanding of the mind, (2) the simplicity of their description, (3) their sheer beauty, (4) their counterintuitive quality, and finally (5) their "spectacularity." Subsequently, the top 10 finalists are rated by hundreds of observers around the world to reveal the top three illusions of the year.

On Dec. 14, 2020, the three top illusions of 2020 were announced.

Coming in at third place is the "Impossible Grid Typography" by Daniël Maarleveld from the Netherlands:

In this illusion, grid-like 3D letters and numbers rotate clockwise on the screen, or is it counter-clockwise? Upon closer inspection, it becomes impossible to decipher which way the shapes are rotating or even whether the shapes are rigid or flexible. The illusion seems to combine the paradoxical topography of a Möbius strip with the bistable perception of a Necker cube. The result is both mind-numbing and mesmerizing to watch.

The second-place illusion is "The Real Thing?" by Matt Pritchard from the UK:

Here, we see what appears to be a mirror reflecting various objects—a can of Coke and a pair of plastic balls. Except, upon moving the objects, the reflections do not behave as expected. In reality, the mirror is not a mirror at all, but rather an opening on a false wall that reveals a second set of objects behind it. The illusion shows how biased our visual system is to interpret surfaces as mirrors when little other information is available.

Finally, the top-rated illusion of 2020 is "3D Schröder Staircase" by Kokichi Sugihara from Japan:

This illusion is a mind-boggling, real-life version of a "Schröder staircase," in which one is never quite sure if the stairs are going up or down. Similar to M.C. Escher's "Ascending and Descending" and the Penrose stairs, which are both two-dimensional renderings, the illusion by Kokichi Sugihara invites the viewer to first interpret the 3D staircase as going down to the right. However, after spinning the display table by 180 degrees, the staircase *still* appears to be going down to the right. In the intermediate angles, one can see that the 3D staircase is not actually shaped as it appears, but the views at 0 and 180 degrees are so convincing that it is nearly impossible for the visual system to perceive the object as it really is.

Each year, the three illusion contest winners take home one of three beautifully designed sculptures designed by Guido Moretti, which are themselves perceptual illusions that appear as different optical illusions depending on where you look at them from. More importantly, the winners, as well as the other top 10 finalists, gain considerable exposure to their work beyond the typical readership of their scholarly publications. In 2015, I was lucky enough to have my submission "Mind-Controlled Motion" selected as a top 10 finalist—as of today, the one-minute video has received over 100,000 views world-wide, far more views than any of my peer-reviewed scientific publications.

As such, the Best Illusion of the Year contest provides unique incentives for perception and cognitive scientists to put their most fascinating work out there for the world to discover.