Abstract
The temporal structure of ecological stimuli contains events delineated by event boundaries. Previously, it was shown that Sensory Memory (SM) for motion is allocated exclusively to the current event-segment (Tripathy & Öǧmen, 2018, Frontiers in Psychology). It is not clear however how SM is reset and which items in the current event are stored in SM. We considered two models: In the “complete-reset model”, an event boundary purges completely the prior contents of SM and stores exclusively only those items that underwent change at the event boundary. In the “partial-reset model”, all items that are present post-boundary are stored in SM and those that underwent change are updated. Our stimuli contained four disks moving along linear trajectories with different directions. Two of the disks changed their directions at 400ms and the remaining two at 800 ms. In Experiment 1, the disks that changed direction at 400ms were removed from the display at the time the other two disks changed their direction (800 ms), whereas in Experiment 2, they remained on the display until the end of the presentation (1200ms). Subjects were instructed to report the directions of cued disk(s) from different event segments with varying cue delays. We used two signatures of SM to assess its contents: Rapid decay with cue-delay and partial-report superiority. The results of Experiment 1 showed that the items that changed at the most recent event boundary were stored in SM. Items from previous event segments were not. In Experiment 2, the results indicated that only items that were present after the event boundary were stored in SM. Taken together, the results support the partial-reset model.