PREFRONTAL CONTRIBUTIONS TO MEMORY IN THE YOUNG AND OLD

该项目的目标是从认知和神经上更准确地刻画短期记忆或工作记忆(WM；Baddeley，1986)和事件记忆或情节记忆(Tulving，1972)所涉及的过程。尽管工作记忆和情景记忆通常是分开讨论的，但研究人员越来越一致地认为，共同的认知过程，即执行功能，对工作记忆和情景记忆的表现都有贡献。不幸的是，尽管研究人员已经提出了几个模型来说明这些执行功能可能是什么，以及它们是如何参与WM和情景记忆的，但对辅助这些功能的皮质网络的识别一直滞后。现有证据表明，前额叶皮质(PFC)区域尤其参与这些功能。例如，对WM的神经成像研究表明，尽管PFC的腹侧区域参与了意识中“在线”表征的保持(主动维护)，但背侧区域更多地参与了对这些主动表征的操作(操作)。虽然这些发现来自对工作记忆的研究，但同样的机制也可能有助于编码和提取事件的特定知觉细节，这对确定情节记忆的来源是有用的(例如，确定事件发生的时间、地点和方式，区分感知事件与思想和心理图像)。因此，编码和检索这种来源特定的信息可能需要有助于WM和情节记忆的执行功能。

The goal of the proposed project is to more precisely characterize, cognitively and neurally, processes involved in short-term, or working memory (WM; Baddeley, 1986), and memory for events, or episodic memory (Tulving, 1972). Although WM and episodic memory are typically discussed separately, there is a growing consensus among researchers that common cognitive processes, referred to as executive functions, contribute to both WM and episodic memory performance. Unfortunately, although researchers have proposed several models to specify what these executive functions might be and how they are involved in WM and episodic memory, identification of the cortical networks subserving these functions has lagged behind. Available evidence indicates that regions of prefrontal cortex (PFC) are particularly involved in these functions. For example, neuroimaging studies of WM suggest that whereas ventral regions of PFC are involved in keeping representations "on-line" in consciousness (active maintenance), dorsal regions are more involved in performing operations upon these active representations (manipulation). Although these finding have emerged from studies of WM, it is possible that the same mechanisms also contribute to the encoding and retrieval of specific perceptual details of events that are useful for determining the source of an episodic memory (e.g., determining when, where, and how an event took place, differentiating perceived events from thoughts and mental images). Thus, encoding and retrieval of this source-specifying information may require executive functions that contribute to both WM and episodic memory.