Fractionating Prefrontal Contributions to Memory

描述(申请人提供)：高阶认知在很大程度上取决于形成和提取对事件的持久记忆的能力，或情景长期记忆(LTM)。前额叶皮质(PFC)被认为在引导LTM形成和提取的认知控制过程中发挥关键作用，在神经(如创伤性脑损伤)和精神障碍(如精神分裂症)中，前额叶皮质(PFC)功能障碍与LTM缺陷有关。澄清特定PFC亚区实施的认知控制过程的性质及其与LTM的关系的研究可以为此类疾病的新诊断和治疗方法提供相关基础。目前的项目将利用来自事件相关功能磁共振成像(FMRI)和事件相关脑电位(ERP)实验的融合证据来测试从前额叶组织的新理论产生的预测。第一个具体目标是明确不同的外侧PFC区域如何对LTM的形成做出贡献。四个事件相关fMRI实验将检验这一假设，即PFC的腹外侧区通过选择和维持与目标相关的项目表征来调节LTM的形成，而PFC背外侧区通过形成和操纵记忆中活跃的多个项目之间的关系来调节LTM的形成。第二个具体目标是明确前部PFC对LTM提取的贡献。我将测试这一假设，即前部PFC对于指定将被用来做出记忆决定的信息种类至关重要。这一假说对提取过程中前部PFC募集的时间和功能特征做出了具体的预测。这一假说将与三项fMRI和三项ERP研究中的相互竞争的描述进行对比，这两项研究将分别检查记忆决定标准的选择和维护过程中以及成功记忆提取过程中的PFC活动。这些研究的结果将使一个理论的发展成为可能，该理论描述了由与记忆有关的特定前额叶区域执行的过程，无论是在认知上还是在神经上。

DESCRIPTION (provided by applicant): Higher order cognition depends critically on the ability to form and retrieve lasting memories for events, or episodic long-term memory (LTM). The prefrontal cortex (PFC) is thought to play a critical role in the implementation of cognitive control processes that guide LTM formation and retrieval, and dysfunction of the prefrontal cortex (PFC) in neurological (e.g., traumatic brain injury) and psychiatric (e.g., schizophrenia) disorders has been linked to deficits in LTM. Research clarifying the nature of cognitive control processes implemented by specific PFC subregions and their relationship to LTM can provide a relevant foundation for new diagnostic and therapeutic approaches to such conditions. The current project will utilize converging evidence from event-related functional magnetic resonance imaging (fMRI) and event-related brain potential (ERP) experiments to test predictions generated from a novel theory of prefrontal organization. The first specific aim is to specify how different lateral PFC regions contribute to LTM formation. Four event-related fMRI experiments will test the hypothesis that ventrolateral regions of PFC modulate LTM formation through the selection and maintenance of goal-relevant item representations, whereas dorsolateral PFC regions through the formation and manipulation of relations between multiple items that are active in memory. The second specific aim is to specify how anterior PFC contributes to LTM retrieval. I will test the hypothesis that anterior PFC is critical for specifying the kinds of information that will be used to make a memory decision. This hypothesis makes specific predictions about both the timing and the functional characteristics of anterior PFC recruitment during retrieval. This hypothesis will be contrasted against competing accounts in three fMRI and three ERP studies that will separately examine PFC activity during the selection and maintenance of memory decision criteria and during successful memory retrieval. Results from these studies will enable the development of a theory that characterizes, both cognitively and neurally, the processes implemented by specific prefrontal regions that relate to memory.