Eye movements and event segmentation: Eye movements reveal age-related differences in event model updating.

People spontaneously segment continuous ongoing actions into sequences of events. Prior research found that gaze similarity and pupil dilation increase at event boundaries and that older adults segment more idiosyncratically than do young adults. We used eye tracking to explore age-related differences in gaze similarity (i.e., the extent to which individuals look at the same places at the same time as others) and pupil dilation at event boundaries. Older and young adults watched naturalistic videos of actors performing everyday activities while we tracked their eye movements. Afterward, they segmented the videos into subevents. Replicating prior work, we found that pupil size and gaze similarity increased at event boundaries. Thus, there were fewer individual differences in eye position at boundaries. We also found that young adults had higher gaze similarity than older adults throughout an entire video and at event boundaries. This study is the first to show that age-related differences in how people parse continuous everyday activities into events may be partially explained by individual differences in gaze patterns. Those who segment less normatively may do so because they fixate less normative regions. Results have implications for future interventions designed to improve encoding in older adults. (PsycInfo Database Record (c) 2024 APA, all rights reserved).