Unedited running notes from TEDGlobal 2009.

Beau Lotto began with a simple game for the audience, based on an illusion. He showed two panels covered with large dots of a variety of colors. The backgrounds of the two panels were white and black, respectively. He then surveyed the audience to find which dots across the two boards were the same colors. The audience split three ways in their guesses, and most were wrong. Lotto said that this tendency to see color “incorrectly” based on context uncovers a crucial fact about the way we’re wired:

We have no direct access to our physical world other than through our senses, and the light that falls on our eyes depends on the color of objects and the color of the space between us and those objects. For this reason, the same image with any single parameter changed would have a completely different appearance.

The patterns of light that fall on our eyes is meaningless — it could mean literally anything. And that’s true of sensory information generally. So, how do we see? The brain evolved to find patterns and associate those patterns with behavioral meaning.

Our brain is good at quickly re-defining reality. He showed two identical desert scenes, one below a red panel and another under a green panel. As you stare at the images, the brain learns that the green and red are important for context. When the context is removes the scenes’ appearance dramatically changes. (The crowd oohed when Lotto removed the colored panels.)

These various illusions illustrate how the brain modifies meaning based on sensory information. But we are not the only creatures to see illusions. Bumble bees see illusions in much the same way as we do. Lotto shows this with a science-art project called the Bee Matrix. Using colored lights, he shows that bees’ behavior can be manipulated with color information that interferes with their ability to recognize patterns in order to find nectar.

Illusions are often used to demonstrate “the fragility of our senses.” Lotto says this idea is rubbish. If our senses were fragile, we would not be here. We evolved to see the world in the way it was useful, and how we see is continually re-defining normality.

How can we exploit this tendency for the better? He shows an amazing wearable interface that interprets visual information as sound, and this allows a blind person to successfully navigate the room based only on the sound information.

No one is an outside observer of nature. We are not defined by the bits that make us up — but our environment, our ecology. Only through uncertainty is there potential for understanding.

Photo: Beau Lotto at TEDGlobal 2009, Session 5: ” Hidden algorithm,” July 22, 2009, in Oxford, UK. Credit: TED / James Duncan Davidson