Semantic knowledge and hierarchical event structure can scaffold memory for temporal order.

Remembering the temporal dynamics of past experiences helps people plan for the future. Previous studies using discrete pictorial stimuli showed that people are better at remembering the temporal order of items occurring within the same perceptual context than items spanning across a contextual boundary, suggesting that event segmentation can structure temporal order memory by resetting item-level binding mechanisms. However, in meaningful everyday scenarios, other mechanisms may play equal or greater roles: Two potentially powerful candidates are hierarchical event structure and knowledge about typical temporal order. In a pair of experiments testing order memory with both short (2.5-min) and longer (20-min) delays, we presented narratives that described everyday activities with semantic constraints on order for fine-grained actions or for coarse-grained activity units. Constraints on either level improved order memory, at both delays. In some cases, this reversed the typical finding that temporal order memory within events is better than across events. An additional experiment revealed that serial recall was chunked based on coarse-level event membership and that semantic order constraints helped organize recall order. A final experiment showed that even in the absence of semantic constraints on coarse-grained activity, participants could use episodic memory for coarse-grained order to constrain memory for fine-grained order, given accurate source memory. Collectively, these results provide evidence for important roles played by hierarchical event structure and prior knowledge in scaffolding reconstructive memory, indicating that reconstruction processes use multiple sources of information in addition to simple episodic associations between fine-grained units. (PsycInfo Database Record (c) 2026 APA, all rights reserved).