Illusory motion reversal (IMR) of periodic moving patterns—such as ceiling fans and hubcaps—can be sporadically observed under continuous light sources (Kline, Holcombe, & Eagleman,
2004; Purves, Paydarfar, & Andrews,
1996; Schouten,
1967; VanRullen, Reddy, & Koch,
2005). One explanation for this phenomenon, offered by Purves et al. (
1996), was based on the hypothesis that the visual system takes snapshots of the scene—in other words, it processes discrete epochs of sensory input, and concatenates them to construct a continuous percept (Andrews, White, Binder, & Purves,
1996). In analogy to the wagon–wheel illusion seen on film, it was suggested that spatiotemporal information between perceptual frames is lost, causing the visual system to mismatch the periodic elements of the stimulus between frames. Thus, through a process of correspondence matching (Burt & Sperling,
1981; Caelli, Manning, & Finlay,
1993), a wheel spoke traveling more than one half of a period clockwise between snapshots will erroneously be matched with its predecessor, giving the impression that the preceding spoke traveled less than half of a period counterclockwise between frames.