Most observers perceive a slow rotation of the ring, periodically interrupted by sharp and fast rotatory jumps. These fast jumps are an illusion, produced by a series of three replacements of the random texture by new, uncorrelated random textures (lasting 50 ms) containing no coherent motion signal. Nevertheless, most observers report perceiving jumps between about 20° and 90° of rotation in the direction opposite to the preceding slow movement. The fact that the fast jumps are usually opposite to the slow rotation can be verified by reversing the rotation direction.

You can see a slowed-down version of the stimulus by clicking on the "Go to slow motion" button.