Ames Room

Specially constructed space that demonstrates aspects of visual perception.

People make sense out of visual scenes by relying on various cues. The Ames Room is a specially constructed space that demonstrates the power of these cues. Normally, people use monocular depth cues such as relative size and height in the visual plane as indicators of depth. If two people of similar size stand a distance part, the one closer to the viewer appears larger. Similarly, the person farther away appears higher in the visual plane.

An Ames Room is constructed to look like a normal room. In reality, the floor slants up on one side and, at the same time, slopes up from front to back. Finally, the back wall is slanted so that one side is closer to the viewer than the other. The figure below shows a top view of the shape of the room and the spot from which the viewer looks at the scene.

If one person stands at the back right corner of the room (Person B), and another person at the left corner (Person A), Person A should appear somewhat smaller than Person B because Person A is farther from the viewer. However, because the room is constructed so that the back wall looks normal, the viewer has no depth cues and Person A appears unusually small, while Person B appears very large. If a person moves from one corner to the other, he gives the illusion of shrinking or growing as he moves. That is, the cues that people normally use for size are so powerful that viewers see things that could not possibly be true.