Motion duration is overestimated behind an occluder in action and perception tasks

Abstract

Motion estimation behind an occluder is a common task in situations like crossing the street or passing another car. People tend to overestimate the duration of an object's motion when it gets occluded for subsecond motion durations. Here, we explored (a) whether this bias depended on the type of interceptive action: discrete keypress versus continuous reach and (b) whether it was present in a perception task without an interceptive action. We used a prediction-motion task and presented a bar moving across the screen with a constant velocity that later became occluded. In the action task, participants stopped the occluded bar when they thought the bar reached the goal position via keypress or reach. They were more likely to stop the bar after it passed the goal position regardless of the action type, suggesting that the duration of occluded motion was overestimated (or its speed was underestimated). In the perception task, where participants judged whether a tone was presented before or after the bar reached the goal position, a similar bias was observed. In both tasks, the bias was near constant across motion durations and directions and grew over trials. We speculate that this robust bias may be due to a temporal illusion, Bayesian slow-motion prior, or the processing of the visible-occluded boundary crossing. Understanding its exact mechanism, the conditions on which it depends, and the relative roles of speed and time perception requires further research.

Grasp Orientation in Ambiguous Settings is Sensitive to Prior Object Motion

“…Of course, the major comparative difference between above studies and this study is the presence of occlusion. Without occlusion, one has a reasonable expectation of greater prediction accuracy (Menceloglu and Song, 2023), yet it appears in this instance that inaccuracy can be achieved in the absence of occlusion as long as the motion is quick and towards ambiguity.…”

“…The copyright holder for this this version posted November 21, 2023. ; https://doi.org/10. 1101/2023 As with Experiment 1, trials within Experiment 2 began with home-pad depression and observation of object movement to an initial angle. However, after the hold-period concluded, initiation of object rotation to the target angle was followed by a 150 ms delay until the go cue sounded.…”