Neural mechanisms of specificity and generalization learning

项目总结 基于记忆的认知既取决于记忆个体经历的具体细节的能力 (专一性)和将不同经验的信息组合在一起以获取新知识的能力 (泛化)。众所周知，海马体快速编码特定的事件，但 记忆泛化的机制还不是很清楚。传统上，分工一直是假定的 在海马体之间，支持快速学习的特异性，与其他记忆系统之间，学习缓慢 并且增量地支持泛化。最近的研究也表明了海马体的作用 在快速推广中，新知识是通过组合少数几个 事件。目前有争议的是，海马体对泛化的贡献是否完全可以用它的 在存储特定体验中的作用，或者海马体是否将各种体验的信息整合到 形成广义知识。此外，还不清楚泛化学习是否在 特定细节的内存开销，或者多种类型的内存表示是否形成并共存 服务于多种形式的认知。当前的项目测试了在DISTINCT表示的假设 特异性水平沿着海马体的长轴平行形成，通过与不同的 皮质区域。更多的前面的广义表示提供了推广。更具体的后部 表征支持记忆专一性，但也可以在某些情况下通知泛化决策 当还没有形成广义表示时。为了检验这些假设，拟议的研究使用 人类在概念学习任务中的功能磁共振成像，在概念学习任务中，特异性学习和概括性学习都是 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以及(3)神经模式进行索引 相似性分析。这些研究将确定记忆泛化的机制(S)及其之间的关系 对于特定事件的记忆，不同表征的形成在多大程度上是策略性的 控制，以及有助于特异性和概括性学习的海马区-大脑皮层相互作用。这个 结果将揭示特定性和概括性是否是单个 神经表征，一个单一的神经系统，可以在以下条件下形成不同类型的记忆表征 不同的任务要求，或形成不同表示的不同神经系统。结果将会通知 当前关于记忆功能的理论有助于调和长达数十年的关于概念本质的争论 申述。在这里获得的基本科学知识将有助于揭示记忆和 在许多神经精神障碍中可能出错的泛化机制。

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. The basic science knowledge obtained here will help shed light on the memory and generalization mechanisms that may go awry in many neuropsychiatric disorders.