Lightness and contrast illusions help illuminate the visual system
You may not have noticed that the banner artwork for this month’s topic is itself an illusion, based on a design by Stuart Anstis: Each diamond is identical, yet each row of diamonds appears to be darker than the row above it. I can construct a simpler version of the illusion with just two squares: [...]
Daniel Simons interview, continued: Change Blindness
Last week I interviewed Daniel Simons for Seed Magazine. But the interview that ran there actually only included a little over half of our discussion. In addition to his work on inattentional blindness, Simons is also a leading figure in a different line of research, called change blindness. Here’s a quick video demonstrating the phenomenon [...]
The hollow mask gets a nose ring!
The hollow face mask illusion is a great three-dimensional effect that’s remarkable because it not only works in movies, it also works in real life. Check this out: This is a computer-generated image (from the Max-Planck-Institut für biologische Kybernetik in Tübingen), but it can just as easily be perceived with a real hollow mask. Here’s [...]
Can Kids Ken Kanizsa?
The Kanizsa Illusion is one of the best-known and simplest visual phenomena: Most adults readily see not only the three “pac-men,” but also the triangle formed by their “mouths.” This effect can be used to create virtual rectangles, stars, and other more complicated shapes. What’s less clear is at what age children are first able [...]
Best Illusion of the Year 2010
I’m here at the Illusion of the year contest, which is held at the symphony hall here in Naples, Florida. It’s an enormous room, just now beginning to fill with some of the pre-eminent vision scientists in the world. Since I have journalist credentials for this conference, I was able to get a sneak peak [...]
Live Blogging at VSS
I’m here at the Vision Sciences Society 2010 convention in Naples, Florida — a fantastic meeting of vision scientists from around the world. So far the wifi is working well, so I’m going to try liveblogging a session. The session I’m at is “Motion: Perception,” moderated by Scott Stevenson. First speaker: Albert van den Berg: [...]
Spinning ellipses perplex the visual system
Take a look at this video (Click on the image to play, QuickTime required): Which ellipse is rotating faster? While at first it seems quite obvious that the ellipse on the right is rotating faster, if you download the movie and play in loop mode, by counting rotations you should be able to convince yourself [...]
May will be a month of illusions
For the next month, I’m going to be blogging about illusions and the people who create them. So let’s get started. Take a look at the following short movie, following the on-screen instructions. Just watch it once! This one is based on an illusion by Stuart Anstis, who in turn based it on a very [...]


