Abstract
In visual images, we perceive both space (as a continuous visual medium) and objects (that inhabit space). Similarly, in dynamic visual experience, we perceive both continuous time and discrete events. What is the relationship between these units of experience? The most intuitive answer is similar to the spatial case: time is perceived as an underlying medium, which is later segmented into discrete event representations. Here we explore the opposite possibility -- that events are perceptually primitive, and that our subjective experience of temporal durations is constructed out of events. In particular, we explore one direct implication of this possibility: if we perceive time in terms of events, then temporal judgments should be influenced by how an object's motion is segmented into discrete perceptual events, independent of other factors. We observed such effects with several types of event segmentation. For example, the subjective duration of an object's motion along a visible path is longer with a smooth trajectory than when the same trajectory is split into shorter independent pieces, played back in a shuffled order (a path shuffling manipulation). Path shuffling apparently disrupts object continuity -- resulting in new event representations, and flushing detailed memories of the previous segments. In contrast, segmentation cues that preserve event continuity (e.g. a continuous path but with segments separated by sharp turns) shorten subjective durations relative to the same stimuli without any segmentation (e.g. when the segments are bound into a single smoothly-curving path, in trajectory inflection manipulations). In all cases, event segmentation was manipulated independently of psychophysical factors previously implicated in time perception, including overall stimulus energy, attention and predictability. These and other results suggest a new way to think about the fundamental relationship between time and events, and imply that time may be less primitive in the mind than it seems to be.