The semantic structure of events consistently influences episodic memory recall over time in young and older adults.

Remembering the past often involves constructing narratives that connect various events. Despite older adults retaining the temporal organization of events, it remains unclear whether content similarity between events influence their recall as they do in young adults. Moreover, it remains to be clarified whether such semantic influence is consistent over time. Here we adopted a naturalistic paradigm involving video-based event encoding and multiple recalls over a week to investigates how semantic relationships among events shape memory in young and older adults. Narratives describing the content of each video were transformed into a network of interconnected events based on semantic similarity. Each event was further segmented into central details (essential to the storyline), or peripheral details (contextual and perceptual information). We found that content similarity between events systematically influenced recall across testing sessions, and similarly in young and older adults. Furthermore, this benefit of the semantic structure of events predicted the amount of central but not peripheral details in participants' narratives. Finally, repeated retrieval stabilized recall within individuals over time without promoting convergence among individuals of the same age group. Our findings highlight the need of using naturalistic stimuli to understand which forms of memory are preserved and preferred in ageing.