The Neural
Control of Vision
L. The Processing of Depth
Figure 58 provides a
demonstration of how differential velocity of movement induces the perception
of depth. When stationary, what you see in this figure is just a bunch
of random dots. Now, right click on the picture and select play. Repeat
to stop. The result is that the display begins to rock back and forth.
Almost immediately you can perceive a three dimensional, rigid object
consisting of 3 layers. This is accomplished by having the dots in the
second and third layers move progressively more rapidly and over a greater
distance than in the first layer. The movement exactly mimics what would
happen if a real three dimensional object of this sort were rocked back
and forth.