Memory hierarchies map onto the hippocampal long axis in humans

Memories, like the internal representation of space, can be recalled at different resolutions ranging from detailed events to more comprehensive, multi-event narratives. Single-cell recordings in rodents indicate that different spatial scales are represented as a gradient along the hippocampal axis. Here, we show that a similar organisation holds for human episodic memory: memory representations systematically vary in scale along the hippocampal long-axis, which may enable the formation of mnemonic hierarchies.