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bioRxiv · 10.64898/2026.07.26.740756

Beyond Temporary Scaffolding: Persistent Hippocampal Engagement and Brain-Wide Network Reorganization in Remote Memory Consolidation

Wang, R.·Keerativittayayut, R.·Morioka, S.·Takeda, M.·Jimura, K.·Hasegawa, I.·Nakahara, K.
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Abstract

The standard model of memory consolidation posits a temporary role for the hippocampus. We challenge this view by combining a novel face-name associative memory task with cross-modal decoding of fMRI data. We demonstrate that the hippocampus remains persistently engaged in representing both recent and remote memories, with distinct subregional contributions: recent memories were represented in the right posterior hippocampus, whereas remote memories additionally recruited the left anterior hippocampus. This sustained hippocampal involvement occurred alongside a large-scale network reorganization. Remote memory retrieval was accompanied by increased global connectivity among semantic regions, yet the hippocampus itself did not emerge as a major hub. Instead, network hubs shifted from the medial prefrontal cortex (mPFC) for recent memories to the mPFC and bilateral inferior parietal lobule for remote memories. These findings reveal a dynamic process in which the hippocampus preserves long-lasting representational functions while the broader memory network undergoes extensive reorganization.

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Wang, R., Keerativittayayut, R., Morioka, S., Takeda, M., Jimura, K., Hasegawa, I., Nakahara, K.. 2026-07-28. Beyond Temporary Scaffolding: Persistent Hippocampal Engagement and Brain-Wide Network Reorganization in Remote Memory Consolidation. https://doi.org/10.64898/2026.07.26.740756

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