Medial temporal lobe contributions to episodic memory

项目摘要 众所周知，内侧颞叶(MTL)中的结构，包括海马体，是必要的 用于形成、巩固和找回新的情节记忆。可能是最常见的 了解支持情节记忆的大脑系统的神经科学方法是检查 对单项试验提供的信息进行编码和检索。虽然这种方法已经产生了显著的 洞察力，它忽略了这样一个事实，即新的体验通常与先前的体验有意义地相关，并且作为 这些都与现有的知识相结合，这样我们就可以保留和更新我们对世界的内部模型。 这一观察提出了一个重要的问题，即我们(1)如何存储作为一部分的个别事件的细节 对于更大的整体，(2)提取跨空隙发生的多个相关事件的结构共性 时间上，以及(3)知识如何构建新的学习。到目前为止，人们对这种神经机制知之甚少。 隐藏在情节记忆的这些关键方面。长期目标是了解 支持开发、表达和使用先验知识，以支持新的情节学习。这个 当前提案的目标是(1)测试先验知识如何以预测的形式 经验的结构可以通过腹内侧支持的招募过程来增加记忆编码 在新的学习中的PFC和(2)测试关于基于特征的整合的假设，该假设导致记忆 相似的功能和环境通过整合演变为具有重叠的皮质表示 机械装置。该项目的中心目标是确定vmPFC和其他皮质区域在 与海马体的沟通，通过先前的知识来调节新学习的益处。这个 这项拟议的研究的基本原理是，更好地理解记忆是如何变得稳定的 随着时间的推移，整合将导致更好的认知疗法来补救记忆丧失。在目标1下，各种 测量/技术--包括行为、功能磁共振成像、脑磁图(MEG)和皮层脑电图术 (ECOG)-将用于检查有关正在展开的事件的预期结构的先验知识如何 影响对事件细节进行时间编码的神经机制。目标1：S的实验将 通过调整当前事件的序列结构的可预测性来建立这一基础研究 了解先验知识如何调节与事件记忆相关的行为和神经过程。 目标2将探索关于相关事件的结构化知识的初始学习，这涉及到 整合不同情节中的相关信息。拟议的实验将把这项工作扩展到 考察跨经验的共性如何通过记忆随着时间的推移而出现 整合。

Project Summary It is well known that structures in the medial temporal lobe (MTL), including the hippocampus, are necessary for the formation, consolidation and retrieval of new episodic memories. Perhaps the most common neuroscientific approach to understanding the brain systems supporting episodic memory is to examine encoding and retrieval of information presented on single trials. While this approach has yielded significant insights, it overlooks the fact that new experiences often are meaningfully related to prior experiences, and as such, are integrated with existing knowledge so that we may retain and update our internal models of the world. This observation raises the important questions of how we (1) store the details of individual events that are part of a greater whole, (2) extract the structural commonalities across multiple related events that occur over gaps in time, and (3) how knowledge structures new learning. To date, little is known about the neural mechanisms underlying these critical aspects of episodic memory. The long-term goal is to understand the mechanisms that support the development, representation and use of prior knowledge to bolster new episodic learning. The objectives of the current proposal are (1) to test a model of how prior knowledge in the form of prediction about the structure of experience can increase memory encoding by recruiting processes supported by ventromedial PFC during new learning and (2) to test hypotheses about feature-based integration that leads memories with similar features and contexts to evolve to have overlapping cortical representations through consolidation mechanisms. The central aim of the project is to establish the role of vmPFC and other cortical regions in communication with the hippocampus in mediating the benefits of new learning with prior knowledge. The rationale for the proposed research is that a better understanding of how the memories become stabilized and integrated over time will lead to better cognitive therapies to remediate memory loss. Under Aim 1, a variety of measures/techniques – including behavior, fMRI, magnetoencephalography (MEG) and electrocorticography (ECoG) – will be used to examine how prior knowledge about the expected structure of an unfolding event influences the neural mechanisms underlying the temporal encoding of event details. Aim 1's experiments will build on this foundational research by modulating the predictability of the sequential structure of a current event to understand how prior knowledge modulates behavior and neural processes associated with event memory. Aim 2 will explore the initial learning of structured knowledge about related events, which involves the integration of related information across distinct episodes. The proposed experiments will extend this work to examine how the representation of commonalities across experiences can emerge with time via memory consolidation.