Center for Neural Science, New York University, New York, New York.
Neuroscience Institute, NYU Langone Medical Center, New York, New York.
J Neurophysiol. 2022 Aug 1;128(2):310-325. doi: 10.1152/jn.00250.2021. Epub 2022 Jul 6.
An integral feature of human memory is the ability to recall past events. What distinguishes such episodic memory from semantic or associative memory is the joint encoding and retrieval of "what," "where," and "when" (WWW) for such events. Surprisingly, little work has addressed whether all three components of WWW are retrieved with equal fidelity when remembering episodes. To study this question, we created a novel task where human participants identified matched or mismatched still images sampled from recently viewed synthetic movies. The mismatch images only probe one of the three WWW components at a time, allowing us to separately test accuracies for each component of the episodes. Crucially, each WWW component in the movies is easily distinguishable in isolation, thereby making any differences in accuracy between components due to how they are joined in memory. We find that memory for "when" has the lowest accuracy, with it being the component most influenced by primacy and recency. Furthermore, the memory of "when" is most susceptible to interference due to changes in task load. These findings suggest that episodes are not stored and retrieved as a coherent whole but instead their components are either stored or retrieved differentially as part of an active reconstruction process. When we store and subsequently retrieve episodes, does the brain encode them holistically or in separate parts that are later reconstructed? Using a task where participants study abstract episodes and on any given trial are probed on the what, where, and when components, we find mnemonic differences between them. Accuracy for "when" memory is the lowest, as it is most influenced by primacy, recency, and interference, suggesting that episodes are not treated holistically by the brain.
人类记忆的一个重要特征是能够回忆过去的事件。这种情景记忆与语义记忆或联想记忆的区别在于，对这些事件进行了“什么”、“哪里”和“何时”（WWW）的联合编码和检索。令人惊讶的是，很少有研究关注在回忆事件时，WWW 的所有三个组成部分是否以相同的保真度被检索。为了研究这个问题，我们创建了一个新的任务，让人类参与者识别最近观看的合成电影中采样的匹配或不匹配的静态图像。不匹配的图像一次只探测 WWW 的三个组成部分之一，使我们能够分别测试每个情节组成部分的准确性。至关重要的是，电影中的每个 WWW 组成部分在孤立的情况下都很容易区分，从而使由于它们在记忆中结合的方式而导致的组件之间的任何准确性差异都变得明显。我们发现，“何时”的记忆准确性最低，它是最受首因效应和近因效应影响的组成部分。此外，由于任务负荷的变化，“何时”的记忆最容易受到干扰。这些发现表明，情节不是作为一个连贯的整体被存储和检索的，而是它们的组成部分作为主动重构过程的一部分被分别存储或检索。当我们存储和随后检索情节时，大脑是整体地还是分别地编码它们，然后再进行重构？使用一种任务，参与者研究抽象情节，在任何给定的试验中都会探测到“什么”、“哪里”和“何时”的组成部分，我们发现它们之间存在记忆差异。“何时”记忆的准确性最低，因为它最受首因、近因和干扰的影响，这表明大脑不会整体地对待情节。
