Spatiotemporal investigations of parietal cortex contributions to episodic memory

描述(申请人提供)：情节记忆是对先前经历的事件的有意识记忆。回忆过去事件和个人经历的能力是适应行为的基本能力。脑功能成像研究表明，除了先前发现的内侧颞叶结构外，在情景记忆提取过程中，也参与了一组一致的分布皮质区域。这个网络中最突出的是外侧和内侧顶叶皮质。然而，尽管有强有力的证据表明在情景提取过程中顶叶参与，但尚不清楚顶叶亚区域在提取过程中执行什么计算，或者是什么机制调节这种贡献。目前的应用程序采用多模式方法来研究人类情景提取过程中外侧和内侧顶叶皮质神经活动的空间和时间模式。我们将在相同的受试者中结合神经成像(功能磁共振成像：fMRI)、电生理学(皮质脑电成像：ECOG)和刺激(脑电刺激：EBS)技术，并将结果数据提交给高级多变量分析。具体地说，我们将使用fMRI定位功能解剖的顶亚区，并在相同的受试者中，使用ECoG量化这些顶亚区内和这些顶亚区之间的时间动力学。最后，我们将使用有针对性的EBS来因果询问这些区域对记忆行为的贡献。这种多模式策略提供了一种在功能上分离顶叶亚区并随后揭示人类顶叶皮质基于提取的激活模式下神经事件的精确时间序列的最佳方法。为了实现这些研究目标，候选人将在斯坦福大学安东尼·瓦格纳博士的指导下追求一系列培训目标，特别是专注于使用功能磁共振成像来研究记忆提取的神经机制。培训将侧重于发展利用功能磁共振成像探测情节记忆的实验范式方面的专业知识，以及利用多变量技术对功能磁共振成像数据进行高级分析的专业知识。将这些技能与候选人之前在内侧顶叶皮质认知电生理学(ECoG)方面的工作结合起来，再加上候选人目前的导师Josef Parvizi博士(共同导师，斯坦福大学)的持续指导，将为开发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学和分析基础。这一应用的多模式方法将在涉及情节提取的顶脑回路上提供重要的新杠杆。这类回路是许多精神健康障碍的核心，对过去事件的过度生动沉思或对过去事件的扭曲回忆分别会导致心理痛苦，如创伤后应激障碍、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.