ow do I define consciousness so that it can be studied with empirical methods? Mystics, poets and philosophers all have their definitions, but none of these are very helpful to a scientist. The best illustration of the difference between conscious and nonconscious processing is Motion Induced Blindness , discovered by Y. Bonneh, A. Cooperman and D. Sagi in 2001. Look for a minute at some location in the triangle defined by the three yellow spots. Try not to move your eyes while the cloud of blue dots swirl around the image.

Notice how the yellow disks wink in and out of existence? When you keep your eyes steady, one or more of the disks disappear. When you move your eyes even a bit, they reappear. Yet as you can assure yourself by directly looking at one of the disks, they remain unchanged throughout, shining brightly. When you see one or more of the yellow disks, you are conscious of them, you can comment upon their color and so on. When they are gone from sight you just don't see them anymore (yet they continue to affect parts of your brain). Simply put, "The Quest for Consciousness" is about discovering the difference in your brain (and that of monkeys, mice, and other animals) between such conscious and nonconscious states. I argue that once we understand the neuronal mechanism that are responsible for conscious sights, smells, and sounds, science will be close to solving the mind-body riddle.