Posterior cingulate cortex and executive control of episodic memory

项目摘要 情景记忆涉及编码和检索过去的经验，以支持学习行为。一边 从这些记忆过程中，它还需要调节记忆的能力（即执行过程）。为 例如，许多现实世界的决策将涉及情景检索，执行过程必须帮助 整合和评估记忆信息（记忆证据）的质量，并指导行为， 无论是决定，行动，还是持续的记忆搜索。而情景记忆编码的神经基础和 提取一直是研究的一个主要焦点，但对其执行方面的了解却少得多。执行 记忆功能可能涉及解剖学基底，其（i）多感觉/联想，（ii）参与 记忆/执行处理，以及（iii）与内侧的两个记忆区域密切相关 颞叶（MTL）和执行前额叶（PFC）区域。先前的非人类灵长类动物研究，以及 人类电生理学和神经成像数据表明，后扣带皮层（PCC）实现了这些功能 的搜索.我们的中心假设是，PCC在执行控制情节中起着关键和独特的作用， 记忆提取我们进一步假设它包括三个亚区：背侧PCC，腹侧PCC， 和压后皮质（RSC）。建议这些次区域发挥互补作用， 检索规则、检索集成和场景感知与转换。在这 PCC是记忆和执行系统的汇聚区，其特定的功能 组织解释了研究和物种之间的先前差异。在这里，我们利用人类颅内 记录，包括PCC内的单个单元数据和刺激，以更好地解析功能组织 这一地区。因此，我们将采用一系列的认知实验，以划定三个PCC亚区 支持记忆处理的编码、检索和执行控制（目标1）。在描绘这些 子区域，我们还将寻求区分PCC反应与记忆中发生的反应（MTL）， 执行（dlPFC和ACC）功能网络（目标2）。最后，根据这些观察，我们将 证明PCC子区域对行为和局部/网络活动的因果作用（目标3）。通过研究 PCC是记忆和执行系统的融合区，可以在阐明PCC如何 在日常行为中未能成功地利用过去的经验可能是两者的共同症状 神经退行性疾病（如阿尔茨海默病）和多种精神疾病（如精神分裂症） 暗示PCC功能障碍。

Project Summary Episodic memory involves the encoding and retrieval of past experiences to support learned behavior. Aside from these mnemonic processes, it also requires the ability to regulate memory (i.e. executive processes). For example, many real-world decisions will engage episodic retrieval, for which executive processes must help to integrate and evaluate the quality of remembered information (mnemonic evidence) and guide behavior to either decision, action, or continued memory search. While the neural basis of episodic memory encoding and retrieval have been a major focus of research, far less is known about its executive aspects. Executive mnemonic functions likely involve an anatomical substrate that is (i) multisensory/associative, (ii) engaged by memory/executive processing, and (iii) strongly interconnected with both mnemonic regions in the medial temporal lobe (MTL) and executive prefrontal (PFC) regions. Prior non-human primate studies, as well as human electrophysiology and neuroimaging data, suggest that posterior cingulate cortex (PCC) fulfills these criteria. Our central hypothesis is that the PCC plays a critical and unique role in executive control of episodic memory retrieval. We further hypothesize that it comprises three subregions regions: dorsal PCC, ventral PCC and retrosplenial cortex (RSC). These subregions are proposed to play complementary roles, corresponding to retrieval regulation, retrieval integration, and scene perception and transformation, respectively. In this account, PCC is a convergence zone of memory and executive systems, whose specific functional organization accounts for prior discrepancies between studies and species. Here, we utilize human intracranial recordings, including single unit data and stimulation within PCC, to better resolve the functional organization of this region. We will therefore employ an array of cognitive experiments to delineate three PCC subregions supporting the encoding, retrieval and executive control of memory processing (Aim 1). In delineating these subregions, we will also seek to differentiate PCC responses from those occurring in memory (MTL) and executive (dlPFC & ACC) functional networks (Aim 2). Finally, based on these observations, we will demonstrate the causal role of PCC subregions on behavior and local/network activity (Aim 3). By studying PCC, a convergence zone of memory and executive systems, progress can be made in elucidating how the failure to successfully leverage past experiences in daily behavior can occur as a common symptom of both neurodegenerative disease (e.g. Alzheimer’s disease) and multiple psychiatric conditions (e.g. schizophrenia) implicating PCC dysfunction.