A review of the footsteps illusion

Studies on the footsteps illusion proposed by Anstis (2001) and its variants are reviewed in this article. The footsteps illusion has been explained as a difference in perceived speed depending on edge contrast (Thompson, 1982). In addition to this explanation, it is suggested that the footsteps illusion and its variants can also be attributed to the geometrical illusion presented by Gregory and Heard (1983), to the extinction effect similar to hidden images by Wade (1990), and to subsequent position or motion captures. Related illusions, for example, the kickback illusion (Howe, Thompson, Anstis, Sagreiya, & Livingstone, 2006), the kick-forward illusion, the driving-on-a-bumpy-road illusion, or the footsteps illusion based upon reverse phi motion, are discussed in this article.