ELECTROPHYSIOLOGICAL MEASURES OF HUMAN MEMORY FUNCTIONS

该项目的主要长期目标是推进我们对人类记忆的神经认知基础的理解。所研究的中心记忆功能是那些负责成功回忆个人经历事件的功能。情景记忆缺陷在神经和精神疾病以及正常衰老中极为常见。然而，找到更好的治疗记忆障碍的方法的关键一步是了解健康人记忆功能的神经认知结构。提出的研究基于这样一个前提，即情景回忆可以通过使用方法来监测其发生时的组成过程来最有效地研究。换句话说，必须使用与相关神经计算相对应的神经生理学测量，以便最终破译正常和紊乱的人类记忆的大脑基质。拟议的研究计划包括9个实验，旨在利用健康志愿者头皮电极的非侵入性脑电位记录来研究一系列情景记忆功能。这些事件相关电位（ERPs）似乎对负责有效编码和检索存储信息的过程很敏感，正如FIRST奖支持的几项先前研究所显示的那样。其中许多研究都使用了记忆测试，在这些测试中，受试者没有被明确询问他们的记忆。这些内隐记忆测试表明，一些记忆功能与那些产生情景记忆的功能是分开的。因此，内隐记忆和回忆之间的对比可以在认知和神经机制方面提供极其丰富的信息。因此，来自大脑的电记录将用于监测负责回忆和内隐记忆的记忆功能，提供记忆处理的独立测量，其时间分辨率是目前任何可用的研究人脑活动的方法所无法超越的。两种补充方法也将用于支持神经解剖学理论：功能磁共振成像（在2个拟议的实验中）和脑电源建模。这组实验的结果将阐明一组神经测量指标的具体记忆过程。三个具体目标是：(1)提供证据支持大脑电活动的测量可以用来监测有助于情景回忆的几种功能；(2)直接对比情景记忆和内隐记忆的ERP相关；(3)将人类受试者的大脑功能测量数据与当前的巩固和检索神经生物学模型相结合。

The major long-term objective of this project is to advance our understanding of the neurocognitive foundations of human memory. The central memory functions under study are those responsible for the successful recollection of personally experienced episodes. Deficits in episodic memory are extremely common in neurological and psychiatric disorders and in normal aging. However, a critical step towards finding better ways to treat people with memory difficulties is to understand the neurocognitive structure of memory functions in healthy individuals. The proposed research rests on the premise that episodic recollection can be most effectively studied by using methods to monitor the constituent processes as they occur. In other words, neurophysiological measures that correspond to relevant neural computations must be used in order to ultimately decipher the brain substrates of normal and disordered human memory. The proposed research plan includes 9 experiments designed to investigate a range of episodic memory functions using noninvasive recordings of brain potentials from scalp electrodes in healthy volunteers. These event-related potentials (ERPs) appear to be sensitive to processes responsible for effectively encoding and retrieving stored information, as shown in several prior studies supported by the FIRST award. Many of these studies used memory tests in which subjects were not explicitly queried about their memories. These implicit memory tests show that some memory functions are separate from those that give rise to episodic recollection. Contrasts between implicit memory and recollection can thus be extremely informative with respect to both cognitive and neural mechanisms. Accordingly, electrical recordings from the brain will be used to monitor memory functions responsible for both recollection and implicit memory, providing independent measures of memory processing with a temporal resolution unsurpassed by any currently available method for studying the human brain in action. Two supplemental methods will also be used to support neuroanatomical theorizing: functional magnetic resonance imaging (in 2 of the proposed experiments) and brain electrical source modeling. Results from this set of experiments will elucidate a set of neural measures that index specific memory processes. The 3 specific aims are: (1) to provide evidence supporting the idea that measures of the electrical activity of the brain can be used to monitor several functions that contribute to episodic recollection; (2) to directly contrast ERP correlates of episodic recollection and ERP correlates of implicit memory; and (3) to bring data on measures of brain function in human subjects to bear on current neurobiological models of consolidation and retrieval.