Mapping Human Memory with Electrocorticography & Chronometric Stimulation

描述（由申请人提供）：本项目的目标是确定低频振荡是否作为协调人类情景记忆下的皮层区域的机制。为了解决这个问题，我们将首先采用创新的多小叶皮质电图（ECOG）记录患者，以确定事件记忆，以前的研究和我们的初步工作强烈建议，包括内侧颞叶，前额叶皮层和顶叶皮层的相互连接的大脑区域的集合。然后，我们将使用计时刺激扰乱同一患者的高连通性区域（枢纽），这涉及同时记录和刺激两个不同的大脑区域。计时刺激是有利的，因为它涉及模仿另一个大脑区域中正在进行的记录活动的频率和幅度的刺激，潜在地减轻刺激到其他大脑区域的不必要的传播，同时提供对神经通信实际上可能如何发生的洞察。我们将采用两种不同的刺激方法与这种方法，无论是同相或异相刺激与正在进行的记录振荡连接枢纽。这将允许我们确定1）具有高度连接性的区域（“枢纽”）是否是情景记忆所必需的2）同相、相干振荡是否可以增强情景记忆提取3）异相振荡是否导致记忆表现的下降。我们的方法在这里结合了创新的工具，如皮质电图和计时刺激在人类和分析技术，涉及图论。这些反过来将使我们能够进一步了解大脑区域网络如何以及以何种方式相互作用，作为它们在情景记忆中的作用的一部分。这项工作与临床研究有关，因为它可以提供对其他大脑区域在多大程度上可以补偿中风相关病变后内侧颞叶（情节记忆中的已知“枢纽”）功能丧失的洞察力。它还将促进我们对设计和实施深部脑刺激器以治疗伴随神经疾病的认知障碍的潜在方法的理解。例如，如果这里概述的实验是成功的，它们将意味着将刺激时间与远程记录的振荡活动同步的设备可以恢复甚至增强患有神经疾病的患者受损的记忆功能。

DESCRIPTION (provided by applicant): The goal of this project is to determine whether low frequency oscillations serve as a mechanism for coordinating cortical areas underlying human episodic memory. To address this issue, we will first employ innovative multilobular electrocortigraphic (ECOG) recordings in patients to determine the sets of interconnected brain areas underlying episodic memory, which previous research and our preliminary work strongly suggest to include the medial temporal lobes, prefrontal cortex, and parietal cortex. We will then perturb areas of high connectivity (hubs) in the same patients using chronometric stimulation, which involves simultaneous recording and stimulation from two different brain regions. Chronometric stimulation is advantageous because it involves stimulation that mimics the frequency and amplitude of on-going recorded activity in another brain region, potentially mitigating unwanted spread of stimulation to other brain areas and at the same time providing insight into how neural communication might actually occur. We will employ two different stimulation methods with this approach, either in phase or out of phase stimulation with the on-going recorded oscillations in connecting hubs. This will allow us to determine whether 1) areas with high degrees of connectivity ("hubs") are necessary for episodic memory 2) whether in- phase, coherent oscillatory can enhance episodic memory retrieval 3) whether out-of- phase oscillations result in decrements in memory performance. Our approach here combines innovative tools, such as electrocorticography and chronometric stimulation in humans and analysis techniques involving graph theory. These in turn will allow us to advance our understanding of how and in what manner networks of brain regions interact as part of their role in episodic memory. This work is relevant to clinical research because it can provide insight into the extent to which other brain regions can compensate for lost function following stroke-related lesions to the medial temporal lobes, a known "hub" in episodic memory. It will also advance our understanding of potential ways to design and implement deep brain stimulators to treat cognitive impairments accompanying neural disease. For example, if the experiments outlined here are successful, they would imply that devices that time stimulation to be in-phase with distant recorded oscillatory activity could restore or even enhance impaired memory function in patients suffering from neural disease.