Context-dependent abstraction of temporal relationships during naturalistic episodic memory.

How does the human brain represent how far apart in time two remembered moments occurred? Healthy adults played a first-person interactive video game and subsequently judged the temporal order of pairs of event moments during functional MRI. Using representational similarity analysis, we identified a distributed multivoxel activity pattern in the precuneus and surrounding posterior medial cortex whose representational geometry tracked retrieved temporal-distance magnitude across intervals ranging from less than 1 s to approximately 18 min. This representation could not be explained by perceptual similarity, situational change, or task difficulty, and was stronger for events sharing a common episodic context. Applying inhibitory brain stimulation to the precuneus before retrieval attenuated this representational pattern while leaving overall BOLD activity levels unchanged. These findings suggest that the precuneus contributes to organizing temporal relationships among remembered events, representing temporal distance within structured episodic contexts rather than as a simple metric of elapsed time.