Spatiotemporal predictability alters perceived duration of visual events: Memento effect revisited

Does event perception alter perceived duration? Previous research has shown that the perceived duration of a short scene depicting a disk moving along a segmented path is reduced when the temporal order of the motion segments is reversed (Memento effect). This effect has been attributed to the idea that reversed segments give rise to the perception of distinct visual events, whereas continuous segments are perceived as a single event. It has been suggested that the reduction in perceived duration is a result of perceiving multiple distinct events rather than 1. Here, the authors replicate and investigate the origin of the Memento effect. In 4 experiments, they explore the role of the spatiotemporal predictability of the disk's movement as well as the influence of the number of discrete events on perceived duration. Controlling for spatiotemporal predictability eliminates the Memento effect; however, controlling for the number of distinct events does not. Thus, the authors' results suggest that violations in spatiotemporal predictability rather than a varying number of discrete events induce the Memento effect. The authors discuss the impact of these findings for the perception of more naturalistic events.