What constitutes an episode in episodic memory?

The idea of episodic memory implies the existence of a process that segments experience into episodes so that they can be stored in memory. It is therefore surprising that the link between event segmentation and the organization of experiences into episodes in memory has not been addressed. We found that after participants read narratives containing temporal event boundaries at varying locations in the narrative, their long-term associative memory for information across event boundaries was lower than their memory for information within an event. This suggests that event segmentation during encoding resulted in segmentation of those same events in memory. Further, functional imaging data revealed that, across participants, brain activity consistent with the ongoing integration of information within events correlated with this pattern of mnemonic segmentation. These data are the first to address the mechanisms that support the organization of experiences into episodes in long-term memory.