The Freezing Rotation Illusion

Abstract

The freezing rotation illusion arises when a figure is continuously rotating in front of a back and forth rotating ground. The term “freezing rotation” designates the decrease in the perceived rotation speed of a figure when the figure and the ground are turning in equal directions. Subjects had to estimate the rotation speed of a continuously turning figure while the ground was either turning opposite to or with the figure. Their estimations of the figure’s speed were significantly lower, when the ground was moving in the same direction as the figure. In control experiments subjects had to estimate the ground’s speed while the figure was turning opposite to or with the ground. Overall, their estimations of the rotational speed of the ground were not significantly influenced by the rotational direction of the figure