Attentional profiles linked to event segmentation are robust to missing information

Abstract

Everyday experience consists of rapidly unfolding sensory information that humans redescribe as discrete events. Quick and efficient redescription facilitates remembering, responding to, and learning from the ongoing sensory flux. Segmentation seems key to successful redescription: the extent to which viewers can identify boundaries between event units within continuously unfolding activities predicts both memory and action performance. However, what happens to processing when boundary content is missing? Events occurring in naturalistic situations seldom receive continuous undivided attention. As a consequence, information, including boundary content, is likely sometimes missed. In this research, we systematically explored the influence of missing information by asking participants to advance at their own pace through a series of slideshows. Some slideshows, while otherwise matched in content, contained just half of the slides present in other slideshows. Missing content sometimes occurred at boundaries. As it turned out, patterns of attention during slideshow viewing were strikingly similar across matched slideshows despite missing content, even when missing content occurred at boundaries. Moreover, to the extent that viewers compensated with increased attention, missing content did not significantly undercut event recall. These findings seem to further confirm an information optimization account of event processing: event boundaries receive heightened attention because they forecast unpredictability and thus, optimize the uptake of new information. Missing boundary content sparks little change in patterns of attentional modulation, presumably because the underlying predictability parameters of the unfolding activity itself are unchanged by missing content. Optimizing information, thus, enables event processing and recall to be impressively resilient to missing content.

Keywords: Action processing; Event cognition; Event segmentation; Predictability monitoring.

Fig. 1

Selected images from the boot polishing slideshow classified as boundary and within-unit slides. This sequence of images illustrates the consequence of removing every other slide from the 2-fps slideshow to create a 1-fps version

Fig. 2

Alignment of dwell-time patterns across 1-fps and 2-fps slideshow versions. Only matched slides, depicting identical content across the two levels of resolution, are included. FPS frames per second

Fig. 3

Mean residualized dwell times (± standard error) to boundary slides, within-unit slides, and within-unit slides immediately after a boundary that was missed in the 1-fps slideshows (but present in the 2-fps slideshows). fps frames per second

Fig. 4

Average residualized dwell times (± standard error) by region, resolution, and slide type for coarse-level boundaries. Slides occurring one and two pre-boundary and one and two post-boundary were included. Bars in the same color represent the same slide content across 1-fps and 2-fps slideshows (i.e., these are the matched slides). fps frames per second

Fig. 5

Average residualized dwell times (± standard error) by region, resolution, and slide type for fine-level boundaries. Slides occurring one and two pre-boundary and one and two post-boundary were included. Bars in the same color represent the same slide content across 1-fps and 2 fps-slideshows (i.e., these are the matched slides). fps frames per second