School of Psychology, Shaanxi Normal University, Xi'an, 710062, China.
Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
Neuropsychologia. 2019 Sep;132:107135. doi: 10.1016/j.neuropsychologia.2019.107135. Epub 2019 Jul 8.
Reactivation returns a consolidated memory to a plastic state, opening a window for the existing memory to be updated. For episodic memory, learning of competing information upon reactivation either integrates the new information into the reactivated memory or disrupts the reactivated memory directly, but the two effects were found in distinct experimental paradigms and their neural mechanisms are largely unknown. The current study explored the effects and neural mechanisms of episodic memory reactivation using behavioural and MEG techniques. Taking advantage of an independent-cue retrieval procedure, we revealed both the integration and the forgetting effects by a single post-reactivation interference paradigm. However, while the integration effect followed the reconsolidation window, the forgetting effect did not, suggesting only the integration effect being caused by memory reconsolidation. MEG measurements further revealed beta-band power decrease during reactivation and alpha-band power decrease during post-reactivation interference, both of which parametrically predicted the degree of memory integration. But neither the beta nor the alpha desynchronization was related to the forgetting of the original memory. Our results suggest original memory forgetting and new information integration happen in different time periods after memory reactivation, and beta and alpha desynchronizations underlie reconsolidation-mediated episodic memory updating.
再激活将整合记忆恢复到可塑状态，为更新现有记忆打开了一扇窗口。对于情景记忆，再激活时学习竞争信息会将新信息整合到被重新激活的记忆中，或者直接破坏被重新激活的记忆，但这两种效应是在不同的实验范式中发现的，其神经机制在很大程度上尚不清楚。本研究采用行为和 MEG 技术探讨了情景记忆再激活的影响和神经机制。利用独立线索检索程序，我们通过单个再激活后干扰范式揭示了整合和遗忘效应。然而，虽然整合效应遵循再巩固窗口，但遗忘效应并不遵循，这表明只有整合效应是由记忆再巩固引起的。MEG 测量进一步显示，再激活期间β 波段功率降低，再激活后干扰期间α 波段功率降低，这两者都可以参数化预测记忆整合的程度。但β 波和α 波去同步都与原始记忆的遗忘无关。我们的研究结果表明，原始记忆遗忘和新信息整合发生在记忆再激活后的不同时间，β 和α 去同步是再巩固介导的情景记忆更新的基础。
