Representation of spatiotemporal information in human episodic memory and navigation

这个项目的目标是确定空间和时间的神经基础 组成人类情景记忆和导航的组成部分。损坏 人类海马体导致情节记忆和 但行为和神经上的共同点仍不清楚。我们 假设空间和时间上下文表示，这反过来又包括 时间顺序和时间间隔，在两个部分的情景记忆和导航的基础 重叠和独特的方式。为了了解海马体如何编码空间信息 和时间背景下，目标1侧重于采用高分辨率海马 功能磁共振成像（fMRI）和颅内脑电描记术（iEEG） 为了更好地了解人类微电路的具体贡献， 海马体。基于我们过去开发的实验和模型 在资助期间，我们假设海马CA 3/DG亚区在 空间与时间背景的差异，而CA 1在整合中发挥作用 这两种不同形式的背景的共同点。高分辨率海马 功能磁共振成像实验直接测试这些想法，采用实验的组合， 将空间和时间处理与多变量模式分开的设计 分析（MVPA）来映射这些行为的海马分布代码 件.海马脑电实验的重点是了解如何低- 频率振荡编码空间距离和时间背景，特别是 时间间隔，我们假设这主要涉及到的差异， 振荡频率。目标2提供了一个更“宏观”的视角， 情景记忆和导航，重点是独特的皮质海马和 包括空间与时间（顺序和间隔）的皮质-皮质网络 语境处理基于实验和我们开发的模型， 在过去的资助期间，我们将采用全脑功能磁共振成像和多小叶iEEG 记录在患者接受癫痫监测，以确定独特的皮质 对空间和时间背景的贡献。我们假设独特的结构 网络和相互作用的频率，如前额叶-海马相互作用， 时间背景和空间背景的顶叶-压后-海马相互作用 上下文，对这些表示至关重要。建议的实验直接测试这些 再次采用情节记忆和导航相关的范例。的 这一建议的预期成果是在微观和 宏观层面的尺度，空间与时间背景如何有助于人类的情节 记忆和导航具体而言，通过更好地了解 海马电路到情景记忆和导航，我们可以更好地了解 中风和局部缺血等疾病如何影响那里的功能。此外，通过描绘 海马外皮质的贡献，我们可以更好地理解和预测 海马损伤后的补偿。

The goal of this project is to determine the neural basis of the spatial and temporal components that comprise human episodic memory and navigation. Damage to the human hippocampus results in significant impairments to both episodic memory and navigation yet the commonalities behaviorally and neurally remain unclear. We hypothesize that spatial and temporal contextual representations, which in turn include temporal order and interval, underlie episodic memory and navigation in both partially overlapping and unique manners. To understand how the hippocampus codes spatial and temporal context, Aim 1 focuses on employing high-resolution hippocampal functional magnetic resonance imaging (fMRI) and intracranial encephalography (iEEG) to better understand the specific contributions of the microcircuitry of the human hippocampus. Building on experiments and a model we have developed in the past funding period, we hypothesize that hippocampal subfields CA3/DG play a role in differentiation of spatial vs. temporal context while CA1 plays a role in integrating commonalities across these two different forms of context. High-resolution hippocampal fMRI experiments directly test these ideas by employing a combination of experimental designs to tease apart spatial and temporal processing coupled with multivariate pattern analyses (MVPA) to map hippocampal distributed codes for these behavioral components. Hippocampal iEEG experiments focus on understanding how low- frequencies oscillations code both spatial distance and temporal contexts, particularly temporal intervals, which we hypothesize relates primarily to differences in the frequencies of oscillations. Aim 2 provides a more “macro” perspective on human episodic memory and navigation, with a focus on the unique cortical-hippocampal and cortical-cortical networks that comprise spatial vs. temporal (order and interval) contextual processing. Building on experiments and a model we have developed over the past funding period, we will employ both whole brain fMRI and multilobular iEEG recordings in patients undergoing seizure monitoring to determine the unique cortical contributions to spatial vs. temporal context. We hypothesize that unique configurations of networks and frequencies of interactions, such as prefrontal-hippocampal interactions for temporal context and parietal-retrosplenial-hippocampal interactions for spatial context, are critical to these representations. Proposed experiments directly test these ideas by again employing both episodic memory and navigation related paradigms. The expected outcomes from this proposal are a better understanding, at both the micro and macro level scale, of how spatial vs. temporal context contribute to human episodic memory and navigation. Specifically, by better understanding the contributions of the hippocampal circuitry to episodic memory and navigation, we can better understand how diseases like stroke and ischemia impact function there. In addition, by delineating the extra-hippocampal cortical contributions, we can better understand and predict compensation following insults to the hippocampus.