Prism Adaptation

When people first look through prisms that displace the visual world left or right, they experience errors in their behavior. For example, they reach to the side of their coffee cup and may bump into a door frame when walking. With continued exposure to the prisms, however, these errors disappear. The person has adapted to the prisms. When the prisms are removed, the person may initially make similar errors, but now in the opposite direction. These aftereffects demonstrate that a change has occurred in the person's perceptual-motor system (i.e., the organization of senses and limbs), a change that persists until the person relearns the normal manner of interacting with the world. Once an amusing curiosity good for classroom demonstrations, prism adaptation is proving to be ...