Disconnected Dots

DISCONNECTED DOTS illustrates that seeing motion is more complicated than it would seem. Visitors are instructed to hold the card, shown in the picture, horizontally and look down on it. They then move it gently from side to side as they watch the dots. The white and yellow dots appear to "detach" from the background and move more slowly than the other dots. The brain processes information about color and motion separately. The part that interprets motion relies mainly on changes in an object’s brightness, or luminance. Here, the white and yellow dots have the same luminance as its background, so its hard for the brain to see their motion. That is why they seem to lag behind the other dots.