Al Seckel: Your brain is badly wired

Al Seckel, a cognitive neuroscientist and master of visual illusions, explores some of the perceptual illusions that fool our eyes and our brains. Running through example after example of images that buck our expectations, he asks why such tricks make us so happy (The Pursuit of Happiness was the theme of the 2004 TED conference). He even creates some of his own illusions, challenging our notion of what's true.