Spatiotemporal investigations of parietal cortex contributions to episodic memory

描述（由申请人提供）：情景记忆是对先前经历事件的有意识记忆。回忆过去事件和个人经历的能力是适应性行为的基本能力。脑功能成像研究表明，除了先前确定的内侧颞叶结构外，在情景记忆检索过程中，还参与了一组一致的分布皮质区域。在这个网络中最突出的是外侧和内侧顶叶皮层。然而，尽管有强有力的证据表明顶叶参与情景检索，但目前尚不清楚顶叶次区域在检索服务中执行什么计算或什么机制调解这种贡献。目前的应用程序采用多模式的方法来研究在情景检索过程中人类顶叶外侧和内侧皮层的神经活动的空间和时间模式。我们将在同一受试者中结合神经成像（功能磁共振成像：fMRI），电生理学（皮质电图：ECoG）和刺激（脑电刺激：EBS）技术，并将结果数据提交给先进的多变量分析。具体来说，我们将使用功能磁共振成像定位功能解剖顶叶亚区，并在同一受试者中，使用ECoG量化这些顶叶亚区内部和之间的时间动态。最后，我们将使用目标EBS来查询这些区域对内存行为的贡献。这种多模式策略为功能分离顶叶亚区提供了一种最佳方法，并随后揭示了人类顶叶皮层中基于检索的激活模式的神经事件的精确时间序列。为了实现这些研究目标，候选人将在Anthony Wagner博士（斯坦福大学）的指导下追求一系列的训练目标，特别侧重于使用fMRI研究记忆检索的神经机制。培训将侧重于发展用功能磁共振成像探测情景记忆的实验范例方面的专业知识，以及用多元技术对功能磁共振成像数据进行高级分析。将这些技能与候选人之前在内侧顶叶皮层的认知电生理学（ECoG）方面的工作相结合，以及候选人现任导师Josef Parvizi博士（联合导师；斯坦福大学）的持续指导，将为开发一个专注于研究情景记忆的神经认知网络的独立研究项目提供强有力的方法和分析基础。该应用的多模态方法将为涉及情景检索的顶叶回路提供重要的新杠杆。这种回路是许多精神健康障碍的核心，对过去事件的过度和生动的反思或对过去事件的扭曲回忆会导致心理痛苦，例如分别出现创伤后应激障碍、重度抑郁症、广泛性焦虑症或精神分裂症。

DESCRIPTION (provided by applicant): Episodic memory is the conscious memory for previously experienced events. The ability to recollect past events and personal experiences is a fundamental faculty for adaptive behavior. Functional brain imaging studies have shown that, in addition to previously identified structures in the medial temporal lobe, a consistent set of distributed cortical regions are also engaged during episodic memory retrieval. Most prominent among this network has been the lateral and medial parietal cortex. However, despite strong evidence of parietal engagement during episodic retrieval, it is not clear what computations parietal subregions perform in the service of retrieval or what mechanisms mediate this contribution. The current application takes a multimodal approach to studying the spatial and temporal patterns of neural activity in the human lateral and medial parietal cortex during episodic retrieval. We will combine neuroimaging (functional magnetic resonance imaging: fMRI), electrophysiology (electrocorticography: ECoG) and stimulation (electrical brain stimulation: EBS) techniques within the same subjects, and will submit the resulting data to advanced multivariate analyses. Specifically, we will localize functional-anatomic parietal subregions with fMRI, and in the same subjects, quantify the temporal dynamics within and between these parietal subregions using ECoG. Finally, we will use targeted EBS to causally interrogate the contributions of these regions to memory behavior. This multimodal strategy provides an optimal approach for functionally dissociating parietal subregions and subsequently revealing the precise temporal sequence of neural events underlying retrieval-based activation patterns in human parietal cortex. To achieve these research aims, the candidate will pursue a series of training aims under the mentorship of Dr. Anthony Wagner (Stanford University), specifically focused on the use of fMRI to study the neural mechanisms of memory retrieval. Training will focus on developing expertise in experimental paradigms for probing episodic memory with fMRI, and in the advanced analysis of fMRI data with multivariate techniques. Combining these skills with the candidate's previous work on the cognitive electrophysiology (ECoG) of medial parietal cortex, along with ongoing mentoring from the candidate's current advisor Dr. Josef Parvizi (co-mentor; Stanford University), will provide a strong methodological and analytical basis for developing an independent research program focused on studying the neurocognitive networks of episodic memory. The multimodal approach of this application will provide important new leverage on the parietal circuits involved in episodic retrieval. Such circuits lie at the core of many mental health disorders, where excessive and vivid rumination of past events or the distorted recollection of past events contributes to psychological distress, such as post-traumatic stress disorder, major depression, generalized anxiety disorder or schizophrenia, respectively.