Biological Motion

Click the picture above to see the flash illusion.
Do these dots form a figure?
What happens when the dots start to move?

The exhibit shows the movement of lights connected to the joints of a non-existent person. When the lights are motionless, we can't see the person. But when they move again, the brain recreates the image of the person, who we perceive to be walking.

The points of light themselves give us very little information about the outline of the person, but when these specially placed lights are moving, they create a pattern that the brain recognizes as a person walking.

People are so good at recognizing biological movement from a relatively small number of moving points that they know, simply by the way a person walks, if it is a man or a woman or even a specific person they know. The illusion also works when the biological movement is that of an animal.

Try it yourself:
http://www.biomotionlab.ca/Demos/BMLsexID.html