A functional magnetic resonance imaging investigation of the effect of prior experience on event perception and memory in young and older adults.

Familiar activities may support memory in older adulthood by synchronizing neural processing during event encoding. To test this hypothesis, young and older adults watched videos of everyday activities that were either familiar or unfamiliar to their age group, while undergoing magnetic resonance imaging. After scanning, participants completed tests of their event memory. Older adults remembered less information than young adults in the young adult familiar activities. Contrary to our hypothesis, fMRI analyses showed that these deficits were not explained by age-related differences in vmPFC-hippocampal functional connectivity during encoding. Instead, intersubject correlation analyses revealed that older adults' poorer memory of unfamiliar videos was associated with reduced similarities in the spatiotemporal responses across viewers' at encoding. Specifically, young adults exhibited greater neural synchrony than older adults in occipital and ventral temporal cortices while viewing videos depicting activities more familiar to young adults. In contrast, age-related differences in synchrony were not observed for videos depicting activities more familiar to older adults. These findings indicate that familiarity promotes more similar neural processing across individuals and supports more normative event encoding in older adults when activities align with their prior experience. (PsycInfo Database Record (c) 2026 APA, all rights reserved).