Shifts in Context Affect Hippocampal Activity and the Sequence of Recall

People often find that memories linked to the same place or period come to mind together. Visiting a former workplace can prompt recall of events that had not been thought about for years, such as conversations or group activities. Yet a change of setting can also impair access to recent information; for example, when a person enters a room and forgets what they intended to do there. Temporal context models (Howard and Kahana, 2002) provide a framework for understanding these phenomena. They propose that internal context changes gradually, and this drifting state becomes linked to each event. When experiences share a similar context, they are more likely to be retrieved together. However, changes in context can increase the rate of internal neural drift, separating experiences that occurred close together in time. The hippocampus is thought to maintain these representations by integrating spatial and temporal information. Research across neural and behavioral domains indicates that the organization of memory reflects both gradual contextual change and event boundaries. Studies have shown gradual changes in hippocampal activity as time passes during an event, consistent with neural drift (Folkerts et al., 2018). Additionally, hippocampal pattern resets have been observed at event boundaries, such as moving between rooms (Baldassano et al., 2016). These event boundaries segment experience into discrete units, which support the chunking of information in memory (Radvansky and Zacks, 2017). Behavioral work has demonstrated that context changes during learning can disrupt temporal clustering, suggesting that shifts in context weaken temporal associations (DuBrow and Davachi, 2013; Horner et al., 2016). However, prior neural work has not tested whether experimentally induced context changes alter the rate of hippocampal drift. As a result, there is no direct evidence connecting experimentally induced context change, hippocampal drift, and the organization of recall. Rait et al. (2025) provide evidence … Correspondence should be addressed to Jamie P. Cockcroft at jamie.cockcroft{at}york.ac.uk.