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Neural mechanisms of specificity and generalization learning

特异性和泛化学习的神经机制

基本信息

批准号：
10786969
负责人：
Dagmar Zeithamova
金额：
$ 8.16万
依托单位：
UNIVERSITY OF OREGON
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2025-05-31
项目状态：
未结题

项目摘要

Project summary Memory-based cognition depends on both the ability to remember specific details of individual experiences (specificity) and the ability to combine information across experiences to derive new knowledge (generalization). It is well established that the hippocampus rapidly encodes specific events, but the mechanisms of memory generalization are less clear. Traditionally, a division of labor has been postulated between the hippocampus, learning rapidly to support specificity, and other memory systems, learning slowly and incrementally to support generalization. More recent research has also shown a role of the hippocampus in rapid generalization, where new knowledge is derived by combining information across a small number of events. It is currently debated whether the hippocampal contribution to generalization is fully explainable by its role in storing specific experiences or whether the hippocampus integrates information across experiences to form generalized knowledge. Furthermore, it is unclear whether generalization learning proceeds at the expense of memory for specific details or whether multiple types of memory representations form and co-exist to serve multiple forms of cognition. The current project tests the hypotheses that representations at distinct levels of specificity form in parallel along the long axis of the hippocampus through interactions with distinct cortical regions. More anterior generalized representations inform generalization. More posterior specific representations support memory specificity but can also inform generalization decisions under circumstances when generalized representations have not been formed. To test these hypotheses, the proposed studies use functional MRI in humans during concept-learning tasks in which both specificity and generalization learning is indexed using (1) behavioral methods, (2) cognitive modeling and model-based fMRI, and (3) neural pattern similarity analyses. The studies will determine the mechanism(s) of memory generalization and how it relates to memory for specific events, the degree to which the formation of distinct representation is under strategic control, and the hippocampal-cortical interactions that contribute to specificity and generalization learning. The results will reveal whether specificity and generalization are two behavioral expressions supported by a single neural representation, a single neural system that can form different types of memory representations under different task demands, or distinct neural systems that form distinct representations. The results will inform current theories of memory function and help reconcile a decades-long debate regarding the nature of concept representations. In this supplemental application, we request funding for research experience for Troy Houser, a graduate student in the Brain and Memory lab of the PI Dr. Zeithamova. The supplementee will conduct novel analyses addressing alternative hypotheses regarding the organization of specific and generalized memory representations within hippocampus, and receive training in fMRI analyses and grant writing.

项目摘要基于记忆的认知取决于记住个人经历的具体细节的能力（特异性）和将经验中的信息联合收割机结合起来以获得新知识的能力（一般化）。海马体快速编码特定事件是公认的，但是海马体的编码是非常重要的。记忆泛化的机制还不太清楚。传统上，劳动分工被假定为海马之间，学习迅速，以支持特异性，和其他记忆系统，学习缓慢并逐渐支持泛化。最近的研究也显示了海马体的作用在快速概括中，新知识是通过组合少数事件目前还在争论海马体对泛化的贡献是否完全可以用它的海马体在存储特定经验中的作用，或者海马体是否整合了经验中的信息，形成广义知识。此外，目前还不清楚泛化学习是否在特定细节的记忆消耗，或者多种类型的记忆表征是否形成并共存为多种认知形式服务。目前的项目测试的假设，表示在不同的特异性水平通过与不同的神经元相互作用而沿着海马的长轴平行形成，皮质区更靠前的一般化表征告知一般化。更后部特异性表征支持记忆特异性，但也可以在特定情况下告知泛化决策当一般化的表示还没有形成时。为了验证这些假设，拟议的研究使用在概念学习任务中，特异性和概括性学习都是索引使用（1）行为方法，（2）认知建模和基于模型的功能磁共振成像，（3）神经模式相似性分析这些研究将确定记忆泛化的机制以及它们之间的关系对于特定事件的记忆，不同表征的形成在多大程度上是战略性的，控制，以及有助于特异性和泛化学习的大脑皮层相互作用。的结果将揭示是否特异性和泛化是两个行为表达支持一个单一的神经表征，一个单一的神经系统，可以形成不同类型的记忆表征下，不同的任务需求，或者不同的神经系统形成不同的表征。结果将告知目前的记忆功能理论，并帮助调和长达数十年的辩论，关于概念的性质表示。在这份补充申请中，我们要求资助特洛伊·豪泽的研究经验，研究生在大脑和记忆实验室的PI博士。学员将进行新的分析，解决有关组织的具体和广义的替代假设，海马体内的记忆表征，并接受功能磁共振成像分析和赠款写作的培训。