TY - JOUR TI - Phase separation of competing memories along the human hippocampal theta rhythm AU - Kerrén, Casper AU - van Bree, Sander AU - Griffiths, Benjamin J AU - Wimber, Maria A2 - Luo, Huan A2 - Colgin, Laura L A2 - Newman, Ehren L VL - 11 PY - 2022 DA - 2022/11/17 SP - e80633 C1 - eLife 2022;11:e80633 DO - 10.7554/eLife.80633 UR - https://doi.org/10.7554/eLife.80633 AB - Competition between overlapping memories is considered one of the major causes of forgetting, and it is still unknown how the human brain resolves such mnemonic conflict. In the present magnetoencephalography (MEG) study, we empirically tested a computational model that leverages an oscillating inhibition algorithm to minimise overlap between memories. We used a proactive interference task, where a reminder word could be associated with either a single image (non-competitive condition) or two competing images, and participants were asked to always recall the most recently learned word–image association. Time-resolved pattern classifiers were trained to detect the reactivated content of target and competitor memories from MEG sensor patterns, and the timing of these neural reactivations was analysed relative to the phase of the dominant hippocampal 3 Hz theta oscillation. In line with our pre-registered hypotheses, target and competitor reactivations locked to different phases of the hippocampal theta rhythm after several repeated recalls. Participants who behaviourally experienced lower levels of interference also showed larger phase separation between the two overlapping memories. The findings provide evidence that the temporal segregation of memories, orchestrated by slow oscillations, plays a functional role in resolving mnemonic competition by separating and prioritising relevant memories under conditions of high interference. KW - episodic memory KW - proactive interference KW - hippocampus KW - MEG KW - oscillations KW - computational model KW - memory competition KW - forgetting JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -