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 组成人类情节记忆和导航的组件。损坏的地方 人类海马体导致情景记忆和 然而，在行为和神经上的共性仍然不清楚。我们 假设空间和时间上下文表示，这又包括 时间顺序和时间间隔是情节记忆和导航的部分基础 重叠和独特的举止。为了了解海马体是如何编码空间的 和时间背景，目标1专注于使用高分辨率的海马体 功能性磁共振成像(FMRI)和颅内脑电图(IEEG) 为了更好地理解人类微电路的具体贡献 海马体。建立在我们过去开发的实验和模型基础上 资助期，我们假设海马区CA3/DG在 时空语境的分化而CA1在整合中的作用 这两种不同形式的语境的共性。高分辨率海马区 功能磁共振成像实验通过使用实验组合来直接测试这些想法 将空间和时间处理与多变量模式相结合的设计 分析(MVPA)以映射这些行为的海马区分布代码 组件。海马区iEEG实验专注于了解脑电活动有多低 频率振荡编码了空间距离和时间背景，尤其是 时间间隔，我们假设这主要与 振荡的频率。《目标2》为我们提供了一个更宏观的人类视角 情景记忆和导航，重点是独特的皮质-海马区和 构成空间和时间(顺序和间隔)的皮质-皮质网络 上下文处理。以实验和我们开发的模型为基础 在过去的资助期，我们将同时使用全脑功能磁共振成像和多小叶iEEG 接受癫痫监测以确定独特皮质的患者的记录 对空间和时间背景的贡献。我们假设独特的配置 相互作用的网络和频率，例如前额叶-海马体的相互作用 对于时间背景和顶叶-脾后-海马区的空间相互作用 背景，对这些表述至关重要。拟议的实验直接测试这些 通过再次使用情景记忆和与导航相关的范式来获得想法。这个 这项建议的预期结果是更好地理解，在微观和 宏观层面，即空间和时间背景对人类事件的影响 记忆和导航。具体地说，通过更好地理解 海马体回路对情景记忆和导航的作用，我们可以更好地理解 中风和缺血等疾病是如何影响那里的功能的。此外，通过划定 对于海马区外皮质的贡献，我们可以更好地理解和预测 在海马体受到侮辱后的补偿。

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.