Investigating prefrontal contributions to source and temporal order memory for faces and words

前额叶皮层（PFC）包含了人类额叶的大部分，对于调节人类区别于其他灵长类动物的可控、灵活、高级认知能力起着重要作用。其中一种较高的认知能力是对过去个人经历的详细描述进行编码和回忆的能力。这种记忆被称为情景记忆（EM）。神经影像学研究已经发现，在检索项目信息（识别记忆）、与个人过去有关的空间/感知细节（源记忆）和与个人过去有关的时间细节（时间顺序记忆）时，PFC参与的区域差异分别存在。然而，关于这些不同的PFC区域分别贡献了哪些认知过程，以及这些过程本质上是em特异性的，还是与更一般的认知控制或“执行”过程有关，例如：记忆形成和检索过程中基于规则的信息组织（战略组织），任务目标的在线维护，反应协调和反应监测，等等，还有很多争论。当前研究项目的目标是研究PFC对EM检索的区域特异性贡献。具体来说，本研究将使用一种创新的脑成像技术：事件相关功能磁共振成像（event-相关fMRI），来检查健康成年志愿者在执行语言和非语言（面部）刺激的源、时间顺序和项目记忆任务时PFC活动的在线区域变化。在检索时呈现的刺激数量和所需的运动反应数量将被参数化地操纵，并将分别控制策略组织和反应协调过程。用于反应监测过程的刺激+运动反应控制的组合参数操作。这一建议的结果将有助于确定PFC中是否存在与上述执行过程相关的子区域，这些子区域在不同的情境记忆任务和不同的刺激类型中是否一致。

The prefrontal cortex (PFC) comprises most of the human frontal lobes and is known to be important for mediating controlled, flexible, higher cognitive abilities that differentiate human beings from other primates. One such higher cognitive ability, is the ability to encode and recollect highly detailed accounts of our past personal experiences. This type of memory is referred to episodic memory (EM). Neuroimaging studies have identified regional differences in PFC involvement during the retrieval of: item information (recognition memory), spatial/perceptual details pertaining to one's personal past (source memory) and temporal details pertaining to one's personal past (temporal order memory), respectively. However, there is much debate over what cognitive processes these distinct PFC regions contribute, respectively, and whether these processes are EM-specific in nature, or related to more general cognitive control or "executive" processes, such as: rule-based organization of information during memory formation and retrieval(strategic organization), on-line maintenance of task goals, response coordination and response monitoring, to name a few. The goal of the current research project is to investigate the region-specific contributions of PFC to EM retrieval. Specifically, this research will use an innovative brain imaging technique: event-related fMRI, to examine on-line regional changes in PFC activity as healthy adult volunteers perform source, temporal order, and item memory tasks for verbal and non-verbal (face) stimuli. The number of stimuli presented at retrieval, and the number of motor responses required, will be parametrically manipulated across tasks, and will control for strategic organization and response coordination processes, respectively. The combined parametric manipulation of stimulus+motor response controls for response monitoring processes. Results from this proposal will help determine whether there are subregions in PFC that are differentially related to the aforementioned executive processes,  consistently, across context memory tasks and across stimulus type.