Effects of Repetition on Learning and Memory in Amnesia

描述（由申请人提供）：本提案代表了对失忆症患者重复对学习和记忆影响的系统调查。虽然很明显，重复是增强健忘症患者记忆的最有力的方法之一，但对于哪些重复是最有益的，以及不同形式的重复是如何产生效果的，我们知之甚少。目前的研究以区分由内侧颞叶介导的快速学习系统和由新皮层介导的慢速学习系统的框架为指导，并基于重复在每个系统中具有不同影响的假设。本研究的第一部分通过评估三种不同的机制来研究快速内侧颞叶学习系统中的重复，这三种机制被认为有助于记忆功能完整的个体的重复效应，即：(1)编码；(2)工作记忆中的时间；(3)研究阶段检索。我们预测，健忘症患者的这些机制会受损，但我们可以创造条件，使这些损害最小化，从而优化他们的表现。该提案的第二部分涉及重复在慢速新皮层学习系统中的影响。我们对慢速学习系统中重复的性质和特征知之甚少，因为之前的研究未能将慢速新皮层学习的贡献与快速内侧颞叶学习的贡献分离开来。在这里，我们使用了一种新的范式，允许孤立地评估缓慢的新皮层学习系统，并测试这种学习在健忘症患者中是完整的假设。我们还研究了不同的编码和检索条件如何影响基于重复的慢学习，目的是揭示如何在失忆症患者中优化这种学习。对快速和慢速学习系统中重复运作方式的更好理解将阐明这些记忆系统的运作，并将为旨在增强健忘症中不同形式记忆的具体策略的发展提供理论基础。

DESCRIPTION (provided by applicant): This proposal represents a systematic investigation of the effects of repetition on learning and memory in amnesic patients. Although it is clear that repetition provides one of the most powerful methods to enhance memory in amnesia, little is known about the kinds of repetition that are most beneficial, and the mechanisms by which different forms of repetition have their effect. The present studies are guided by a framework that distinguishes between a fast learning system mediated by the medial temporal lobes and a slow learning system mediated by neocortex, and are based on the assumption that repetition has distinct effects in each of these systems. The first section of the proposal examines repetition in the fast medial temporal learning system by evaluating the operation in amnesic patients of three different mechanisms thought to contribute to repetition effects in individuals with intact memory function, namely (1) encoding; (2) time in working memory; and (3) study-phase retrieval. We predict that these mechanisms will be impaired in individuals with amnesia, but that conditions can be created that minimize these impairments, thus optimizing their performance. The second section of the proposal concerns the effects of repetition in the slow neocortical learning system. Little is known about the nature and characteristics of repetition in the slow learning system, because previous studies have failed to isolate the contribution of slow neocortical learning from that of fast medial temporal learning. Here we make use of a novel paradigm that allows assessment of the slow neocortical learning system in isolation and test the hypothesis that such learning is intact in amnesic patients. We also examine how various encoding and retrieval conditions affect repetition-based slow learning, with the aim of uncovering how such learning can be optimized in amnesic patients. A better understanding of the ways in which repetition operates within the fast and the slow learning systems will elucidate the operation of these memory systems and will provide a theoretical basis for the development of specific strategies aimed at enhancing distinct forms of memory in amnesia.