Hippocampal-Neocortical Interactions During Naturalistic Learning

项目摘要 情景记忆是我们个人过去的表征，锚定在时间和空间上。幕式 癫痫、创伤性脑损伤和阿尔茨海默病等神经系统疾病的记忆障碍 严重限制了患者独立工作和生活能力。在日常生活中，大脑必须处理 持续的现在形成对过去的离散记忆。这种将经验解析成有意义的 被称为事件分割的组块是人类情景记忆的基础。功能性神经成像 研究表明，海马体和后皮质网络同时增加， 活动在事件边界和结束，但支持这种分界的神经事件是未知的。 许多啮齿动物的研究表明，神经振荡，特别是θ波，γ波和尖波涟漪 (SWR)活动协调大脑皮层-新皮层的相互作用在这些关键的交界处。 我们的长期目标是发现大脑如何组织和巩固连续的经验， 自然环境。这个建议的目的是测量大脑皮层-新皮层动力学 在关键时刻的情景记忆我们的中心假设是海马体在大脑中发挥着关键作用 通过增强θ-γ活动，分割和巩固新皮层传递的信息， 事件边界和观看后休息期间增加的SWR率。为了验证这些假设，我们将 从接受外科手术侵入性监测的癫痫患者获得颅内EEG（iEEG）记录 治疗受试者将观看一系列具有叙事结构和顺序的短片，然后将 被要求回忆选定的内容。当这个项目成功完成后，我们将完成 目标：目标1。测量海马和中性粒细胞对事件分割的相对贡献 在看电影的时候。目标2.为了测量海马对术后记忆巩固的贡献， 观看休息。目标3：为了测试海马通过电刺激进行事件分割的必要性， 刺激（ES）。 这一提议代表了记忆认知神经科学先前工作的重大进展， 使用iEEG来确定参与记忆自然事件的大脑皮层-新皮层振荡。 该项目在理念和方法上都有创新，因为（1）使用短片来调查人类 情景记忆;（2）啮齿类动物记忆中的关键神经生理学发现向人类情景记忆的转化 记忆;（3）确定海马在事件分割和记忆中的必要性 性能通过ES。我们的研究结果将推进机制指导的评估方法， 治疗神经精神障碍如癫痫和创伤性脑损伤中的记忆功能障碍。

PROJECT SUMMARY Episodic memories are representations of our personal past, anchored to time and space. Episodic memory impairments in neurological disorders like epilepsy, traumatic brain injury, and Alzheimer’s Disease significantly limit patients’ ability to work and live independently. In everyday life, the brain must process the continuous present to form discrete memories of the past. This ability to parse experience into meaningful chunks, termed event segmentation, is foundational to human episodic memory. Functional neuroimaging studies suggest that the hippocampus and a posterior cortical network demonstrate a simultaneous increase in activity at event boundaries and endings, but the neural events supporting this demarcation are unknown. Numerous rodent studies suggest that neural oscillations—particularly theta, gamma, and sharp-wave ripple (SWR) activity—coordinate hippocampal-neocortical interactions at these critical junctures. Our long-term goal is to discover how the brain organizes and consolidates continuous experience under naturalistic circumstances. The objective of this proposal is to measure the hippocampal-neocortical dynamics at key moments in episodic memory. Our central hypothesis is that the hippocampus plays a critical role in segmenting and consolidating information delivered from the neocortex, via enhanced theta-gamma activity at event boundaries and increased SWR rate during post-viewing rest. To test these main hypotheses, we will obtain intracranial EEG (iEEG) recordings from epilepsy patients undergoing invasive monitoring for surgical treatment. Subjects will view a series of short films that possess a narrative structure and sequence, then will be asked to recall selected content. Upon successful completion of this project, we will accomplish the following aims: Aim 1. To measure the relative contributions of hippocampus and PMN to event segmentation during film viewing. Aim 2. To measure the hippocampal contribution to memory consolidation during post- viewing rest. Aim 3. To test the necessity of the hippocampus for event segmentation through electrical stimulation (ES). This proposal represents a significant advance from prior work in the cognitive neuroscience of memory by using iEEG to determine the hippocampal-neocortical oscillations involved in remembering naturalistic events. This project is innovative in concept and method because of (1) the use of short films to investigate human episodic memory; (2) the translation of key neurophysiological findings in rodent memory to human episodic memory; and (3) establishing the necessity of the hippocampus in event segmentation and memory performance through ES. Our findings will advance mechanism-guided approaches to the assessment and remediation of memory dysfunction in neuropsychiatric disorders such as epilepsy and traumatic brain injury.