Ye Zhifang, Zhao Yufei, Allen Emily J, Naselaris Thomas, Kay Kendrick, Hutchinson J Benjamin, Kuhl Brice A
Department of Psychology, University of Oregon, Eugene, OR, USA.
Department of Psychology, University of Minnesota, Minneapolis, MN, USA.
bioRxiv. 2024 Jul 19:2024.07.16.603778. doi: 10.1101/2024.07.16.603778.
A stimulus can be familiar for multiple reasons. It might have been recently encountered, or is similar to recent experience, or is similar to 'typical' experience. Understanding how the brain translates these sources of similarity into memory decisions is a fundamental, but challenging goal. Here, using fMRI, we computed neural similarity between a current stimulus and events from different temporal windows in the past and future (from seconds to days). We show that trial-by-trial memory decisions (is this stimulus 'old'?) were predicted by the in similarity to past vs. future events (temporal asymmetry). This relationship was (i) evident in lateral parietal and occipitotemporal cortices, (ii) strongest when considering events from the recent past (minutes ago), and (iii) most pronounced when veridical (true) memories were weak. These findings suggest a new perspective in which the brain supports memory decisions by comparing what actually occurred to what is likely to occur.
一种刺激可能因多种原因而让人感到熟悉。它可能是最近遇到过的，或者与近期经历相似，又或者与“典型”经历相似。理解大脑如何将这些相似性来源转化为记忆决策是一个基本但具有挑战性的目标。在此，我们使用功能磁共振成像（fMRI）计算了当前刺激与过去和未来不同时间窗口（从几秒到几天）的事件之间的神经相似性。我们发现，逐次试验的记忆决策（这个刺激是“旧的”吗？）可由与过去事件和未来事件的相似性差异（时间不对称性）来预测。这种关系在以下方面表现明显：（i）在外侧顶叶和枕颞叶皮层中；（ii）在考虑最近过去（几分钟前）的事件时最为强烈；（iii）在真实（准确）记忆较弱时最为显著。这些发现提示了一个新的视角，即大脑通过比较实际发生的事情与可能发生的事情来支持记忆决策。
