Three-fold cubes: An object whose form can be interpreted in three different ways

Guy Wallis and David Lloyd
University of Queensland, Australia

(© 2013 Guy Wallis and David Lloyd )

Modern brain imaging techniques are allowing scientists to peer into the workings of the brain as never before. Such studies require visual stimuli whose impact on brain activity can be tracked amongst the hubbub of other thoughts. Ambiguous figures are important in this regard because although the stimulus does not change, the viewer’s mental image does; providing a stimulus-independent link to conscious experience. Although ambiguous figures generally offer two interpretations, they can offer more. Stimuli producing three interpretations are rare, but of especial interest because they provide a more exacting test of what is happening in our brains when perceptions switch.

Facebooktwittermail

When Pretty Faces Turn Ugly: The Flashed Face Distortion Effect

2012 Second prize
Jason Tangen, Sean Murphy and Matthew Thompson
The University of Queensland, Australia

(© 2012 Jason Tangen, Sean Murphy and Matthew Thompson)

When you stare directly at the faces, they look normal. But, if you stare at the cross, the faces quickly turn ugly.

Like many interesting scientific discoveries, this one was an accident. An undergraduate student was working on face photographs for an unrelated experiment when he was suddenly shocked by the deformed faces staring back at him.

The distortion comes from the many differences between each face and the one that follows. A particularly tanned face, for example, will make the next face seem pale and squinty eyes will make normal eyes bulge.

More info here: mbthompson.com/research

Facebooktwittermail

Counter-intuitive illusory contours

2010 Second prize
Bart Anderson
University of Sydney, Australia

© 2010 Bart Anderson

In many natural scenes, portions of occluding surfaces and contours can be camouflaged by having an identical color as their background. It is now well known that the visual system will often generate illusory contours and surfaces in order to fill-in this missing information. It is widely believed that the visual system does this in order to provide the best overall “explanation” of the images that form in our eyes. In this illusion, four circular disks are simply translated back and fourth over a thin square outline. Although all of the image data is fully “explained” by the visible disks, the visual system generates a strong and clearly visible additional illusory contour inside the square outline. This illusion cannot be understood with any known mechanism or theory that has been proposed to explain the formation of illusory contours. This quicktime movie is best viewed by downloading it and playing it in “loop” mode.

Facebooktwittermail

World’s Largest Lightness Illusion

Barton Anderson & Jonathan Winawer

University of South Wales, Australia & MIT, USA

(© 2005 Barton L. Anderson & Jonathan Winawer)

In this illusion, it appears that there is one set of black figures and one set of white figures. In fact, the two sets of figures are exactly identical. They appear different because the surrounding regions they are on cause the visual system to segment the images into layers. Thus one set appears to be white figures behind dark clouds, and the other set appears to be dark figures behind light clouds. If you cut out the figures you will see that they are identical!

See the illusion: movie

Read more about the illusion and possible explanations

Image segmentation and lightness perception Barton L. Anderson & Jonathan Winawer Nature. 2005. 434:79-83

Facebooktwittermail