Shape of the past: Revealing detail arcs while narrating memories of autobiographical life events across the lifespan.

Humans can remember past autobiographical events through extended narratives. How these narrated memories typically unfold, however, remains largely unexplored. We evaluated how autobiographical memory details typically come together in a sample of 235 healthy young, middle-aged, and older adults. We found that details providing background knowledge followed a U shape, such that they were most prevalent in the initial moments of remembering before falling and then rising near the conclusion of the memory's retelling. Details about the scene of the memory declined over time, whereas other event-specific, unique details about the main features of the event followed an inverted U shape, peaking around the midpoint of a remembered event's narration. Whereas most detail arcs were not significantly affected by older age, older adults showed a significant underuse of details describing the scene early in memory retrieval. Our findings suggest that behind the ability to narrate the remembered past is a normative waxing and waning of the details that make autobiographical memories.