3D Schröder Staircase

2020 First prize
Kokichi Sugihara “3D Schröder Staircase”. Meiji University

Author description: A traditional Schröder staircase is a 2D picture having two interpretation, a staircase seen from above and that seen from below, and the second interpretation can be perceived easily if we turn the picture upside-down. The present 3D object also has two interpretations, both of which are staircases seen from above, and the interpretations switch from one to the other when we rotate the object by 180 degrees around the vertical axis.

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The Real Thing??

2020 Second prize
Matt Pritchard “The Real Thing??”.
United Kingdom

Author description: The video shows a series of illusions of perceiving a reflection of a coke can in a mirror. However, the viewer is just looking through an empty frame at a second can. The question is ‘what is the real thing?’ Even when deceptive elements designed to convince the viewer are stripped away, the illusion of seeing a mirror persists when the scene is viewed for a brief moment. Careful examination will reveal discrepancies in the scene but what causes the vision system to make the initial mirror assumption is not yet fully understood.

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Impossible grid typography

2020 Third prize
Daniël Maarleveld. “Impossible grid typography “.
The Netherlands

Author description: When you look at the grid letters, the shapes seem 3D. But on closer examination, nothing seems to add up. Is the shape rigid or flexible? The bottom becomes top, the back becomes front, and it even looks as if parts of the letters rotate in different directions.

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Landloping ladybugs: Frame-induced position shift

– Mark Wexler, Patrick Cavanagh, and Stuart Anstis. “Landloping ladybugs: Frame-induced position shift”. CNRS and Université de Paris, York University, and University of California at San Diego.
France, Canada, and USA.

Author description: One bug seems to flash on the left and the other on the right—although they’re really aligned one below the other, as you can see when the frame is removed. What’s more, a bug moving up and down looks like it’s going around an oval track, and two bugs flashing in the exact same place look like they’re separated. Instead of seeing objects at their absolute positions, we perceive where they are in relation to other visual landmarks, more so than is often recognized. This could make vision stable when the eyes move.

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The Sunray Illusion

– Michael Karlovich & Pascal Wallisch “The Sunray Illusion”. New York University

Author description: When presented with intersecting ring-like shapes, most people see bright rays coming from the center, akin to what they would see when looking at the sun breaking through the clouds. However, these shimmering rays are entirely illusory—they are not actually there. The tendency to perceive illusory rays is stronger if there are more intersection points in these shapes and if they are better aligned, allowing our brains to “connect the dots,” which produces the rays. Thus, this illusion is one example of our tendency to interpret the information presented to us in the environment in the most plausible fashion.

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– Kento Imai and Kenri Kodaka “XRAYSCOPE”. Nagoya City University

Author description: Wilhelm Röntgen discovered the way of seeing through skin using x-rays in late 1895. Now, in 2020, we find this technology is easily reproduced just by casting a light on the surface of the hand, where the contents you see are not necessarily familiar white-colored bones. This unique experience reminds us of computer-based AR (Augmented Reality), but “XRAYSCOPE” requires the following old fashioned items: one half-mirror and two lights to brighten two divided spaces as well as your favorite bone-like objects (e.x. pens, toothbrushes, vegetable sticks and so on).


Subtitles Illusion

– Masashi Atarashi “Subtitles Illusion”. Gojo high school

Author description: On TV or videos like YouTube, when the subtitles are shown by various speeds, the faster ones look closer, while the slower ones look farther away.

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Transparent Knife Illusion

– Blaise Balas and Benjamin Balas “Transparent Knife Illusion”.
Benjamin Franklin Middle School and North Dakota State University

Author description: This is an illusion in which an ordinary knife looks transparent when it is placed in the middle of the tines of a fork. Even if the knife is reflecting other objects that are nearby, the appearance of the fork still makes the knife itself look like it must be see-through. If you lower the knife into position between the fork’s tines from above, the knife appears to transform from a reflective object to a transparent one.

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The Tapioca Tactile Illusion

– Aya Nishii, Masaki Ohno, Masashi Nakatani “The Tapioca Tactile Illusion”.
Keio University

Author description: The tapioca tactile illusion is a variant of the velvet hand illusion that can produce a smooth tactile perception between two hands. This variant is made with a 8-10 mm hole on a piece of cardboard paper or a plastic sheet of 0.3 mm thickness. When an observer sandwiches the slit with two fingers and then moves the fingers back and forth parallel to the slit direction, he/she perceives a smooth tactile texture with a plump feeling like a tapioca pearl.

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Illusory ‘Misty’ Contours

– Russell D. Hamer and Christopher W. Tyler “Illusory ‘Misty’ Contours”.
Florida Atlantic University, Smith-Kettlewell Eye Research Institute, and City University of London
USA and UK

Author description: The primary ‘goal’ of vision is to efficiently identify objects in a scene and organize them into a perceptual 3D space. In real-world scenes, objects occlude other objects in a figure/ground hierarchy, and the visual brain must perceptually complete occluded features. The mechanisms underlying figure-ground segregation and object-completion employ filling-in, leading to some spectacular effects (e.g., illusory contours, Kanizsa triangle). Our illusion is a surprising elaboration: low-contrast, pseudo-random ‘clouds’ are completed across a gap while preserving complex perceptual properties. The visual brain operates on perceptual ‘units’, not just lines and boundaries, extending them as needed to complete the 3D scene.

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