Bramão Inês, Liu Zhenghao, Johansson Mikael
Department of Psychology, Lund University, Sweden.
Department of Psychology, Lund University, Sweden.
Neuropsychologia. 2025 Jun 6;212:109148. doi: 10.1016/j.neuropsychologia.2025.109148. Epub 2025 Apr 12.
Memories link elements across event boundaries, integrating overlapping content experienced at different times and places. Such memory representations are thought to rely on memory integration mechanisms. The present study used multivariate pattern analysis (MVPA) of electroencephalographic (EEG) data to elucidate the temporal dynamics of integrative encoding memory processes. Memory integration was investigated with the associative inference task. Participants learned overlapping paired associates, AB and BC pairs, comprising a word and a picture (a face or a bird) and were later tested on the AC inferred associations. MVPA was used to measure the online reactivation of previously learned AB memories while encoding overlapping but new BC events. Reliable AB reactivation was observed approximately 1500 ms after the onset of the BC event. Participants (n = 29) were divided into two groups according to their AC performance: high and low memory integration. Interestingly, while both groups showed comparable levels of AB reactivation, the reactivation effects were associated with different behavioral consequences. For participants in the high memory-integration group, reactivation was predictive of later AC performance, suggesting that an integrated ABC representation was formed during BC learning. Conversely, for participants in the low memory-integration group, the reactivation of AB was negatively correlated with BC performance, indicating that reactivation of overlapping memories impaired new learning. The present study extends previous literature by revealing the temporal dynamics of the integrative encoding mechanisms and by providing an account of inter-individual differences in the capacity to integrate memories across distinct episodes.
记忆将跨越事件边界的元素联系起来，整合在不同时间和地点经历的重叠内容。这种记忆表征被认为依赖于记忆整合机制。本研究使用脑电图（EEG）数据的多变量模式分析（MVPA）来阐明整合编码记忆过程的时间动态。通过联想推理任务研究记忆整合。参与者学习重叠的配对联想，即AB对和BC对，其中包括一个单词和一幅图片（一张脸或一只鸟），随后对AC推断联想进行测试。MVPA用于在编码重叠但新的BC事件时测量先前学习的AB记忆的在线重新激活。在BC事件开始后约1500毫秒观察到可靠的AB重新激活。参与者（n = 29）根据他们的AC表现分为两组：高记忆整合组和低记忆整合组。有趣的是，虽然两组显示出相当水平的AB重新激活，但重新激活效应与不同的行为结果相关。对于高记忆整合组的参与者，重新激活可预测后期的AC表现，这表明在BC学习期间形成了整合的ABC表征。相反，对于低记忆整合组的参与者，AB的重新激活与BC表现呈负相关，表明重叠记忆的重新激活损害了新的学习。本研究通过揭示整合编码机制的时间动态，并通过解释个体在跨不同情节整合记忆能力方面的差异，扩展了先前的文献。
