Motion Integration Unleashed: New Tricks for an Old Dog

2016 First prize
Mathew T. Harrison and Gideon P. Caplovitz :  “Motion Integration Unleashed: New Tricks for an Old Dog”. University of Nevada Reno, USA

Previous illusions have demonstrated that drifting Gabors that translate across the visual field can appear to move in the wrong direction (i.e. in a direction that is different than the actual translation). Here we show that configurations of drifting Gabors that are stationary can give rise to dramatic global motion percepts: a rotating square, oscillating chopsticks and rolling waves. Although the Gabors themselves are not changing position, the drifting motion within them causes the illusion that the entire configuration is moving!

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Ambiguous Cylinder Illusion

2016 Second prize
Kokichi Sugihara: “Ambiguous Cylinder Illusion”. Meiji University, Japan

The direct views of the objects and their mirror images generate quite different interpretations of the 3D shapes. They look like vertical cylinders, but their sections appear to be different; in one view they appear to be rectangles, while in the other view they appear to be circles. We cannot correct our interpretations although we logically know that they come from the same objects. Even if the object is rotated in front of a viewer, it is difficult to understand the true shape of the object, and thus the illusion does not disappear.

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Silhouette Zoetrope

2016 Third prize
Christine Veras:  “Silhouette Zoetrope”. Nanyang Technological University, Singapore

As an homage to early tropes that have been tricking our senses since the Victorian Era, the Silhouette Zoetrope offers a paradigm shift from the traditional Zoetrope. Not only through the inversion of its structure, but also through the combination between shadow puppet tradition and the early optical toy. The renewal of pre-cinematic optical devices in contemporary times offers a possibility to the public to experience animation beyond the limits of the screen. When the Silhouette Zoetrope is rotated, the slots strobe behind the cutout images, animating them apparently inside the empty slotted cylinder, which creates the illusion of moving silhouettes placed into space.

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Caught Inside A Bubble

– Mark Vergeer, Stuart Anstis and Rob van Lier :  “Caught Inside A Bubble”. University of Leuven, Belgium, Radboud University Nijmegen, The Netherlands, and UC San Diego, USA

In this illusion you can see colors that are not presented on the screen. An image of colored bull’s eyes is alternated with an image containing different sized greyscale bubbles. Although these bubbles are colorless, they will actually appear to be colored. These illusory colors are the afterimages of the bull’s eye colors. The intriguing thing is that the colors of the bubbles appear to be completely different, depending on the size of the bubble. Each bubble ‘captures’ the afterimage of the bull’s eye color that matches the size of the bubble. One colored image causes multiple, completely different afterimages.

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A New Illusion At Your Elbow

– Peter Brugger and Rebekka Meier:  “A New Illusion At Your Elbow”.  University Hospital Zurich, Switzerland

Move your finger slowly along a person’s forearm from the wrist towards the elbow crook – eyes closed, the person will anticipate touch in the elbow crook. This illusory anticipation may rest on our experience of tactile velocities that are usually much faster and make us believe we feel touch at a body location not yet reached. Neural characteristics of skin receptors specialized for slow motion may also contribute to the anticipation error. Like previously described illusions, the elbow crook illusion is larger on the non-dominant arm. Women showed a smaller illusion than men, confirming their reportedly superior cutaneous sensitivity.

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The Dalesmen Singers Illusion

– Mike Pickard and Gurpreet Singh:  “The Dalesmen Singers Illusion”. Sunderland University, UK

Are the letters in the illusion actually moving? The answer is no, they are rock steady on screen!  Only  the letters brightness’s are changed where the fill pulses alternatively between the black and white values of the edges. This creates a tiny impression of movement which is then amplified in the viewers mind by optimisation of  the brightness and colour values in the scene, together with different phasing of the letter fill luminance changes. These create uncertainty in the viewer’s mind and the ability to pin down the precise spatial arrangement of the letters and so the sense of movement is increased.

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Remote Controls

– Arthur G. Shapiro : “Remote Controls ”. American University, USA

Two physically identical rectangular bars become light and dark at the same time, but in some conditions they look as if they wink in alternation.  The appearance of winking (alternating) or blinking (bars in sync) can be controlled by rectangles placed in the vicinity of the modulating bars: the bars blink when the rectangles are far away or adjacent to the bars but wink when there is a gap between the bars and the rectangles. The effect is remarkable because of the sudden change from wink to blink or vice versa, and because the change can occur across large distances.

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The Shrunken Finger Illusion

– Vebjørn Ekroll, Bilge Sayim, Ruth Van der Hallen and Johan Wagemans:  “The Shrunken Finger Illusion”. University of Leuven, Belgium

In the video about the “shrunken finger illusion”, we show you how you can make your own finger feel shorter by putting it into a halved ping-pong ball. To experience the illusion, look at your finger directly from above, with your finger extended upwards towards your eyes. Then, put the halved ping-pong ball on top of it, such that your finger is inside the ball. Now, when you look at the halved ping-pong ball, it will look like a complete ball. But what about your finger? It feels shorter, as if to make space for the illusory ball!

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– Sylvia Wenmackers :  “Millusion”. University of Leuven, Belgium

As far as I know, this is a new illusion involving windmills, so I’ve called it “Millusion”. I experienced it myself while driving in the evening. One turbine seemed to be turning “the wrong way” as compared to the others. By the time I got home, I had figured it out: I had only seen the outlines of the windmills, silhouetted against illuminated clouds behind it. Probably I was looking at the front of most turbines and at the backside of the “wrong” one (or vice versa). Later, I asked scientific illustrator Pieter Torrez to help me animate it, to check this conjecture with a 3D model. It worked!


Lights and Darks in Vision

– Jose-Manuel Alonso:  “Lights and Darks in Vision”. State University of New York, USA

This illusion demonstrates that the perception of dark and light features in a face is strongly influenced by context. A picture of a face is split into a dark-half and light-half version by setting either the light or dark pixels to a fixed gray value (while keeping the other pixels unchanged). The ‘white’ of the eyes in the dark-half picture has the same luminance as the ‘dark’ lips in the light-half version but the lips appear much darker. This strong illusion can be demonstrated with any face or visual scene photographed with a standard digital camera.

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