CONJUNCTIVE REPRESENTATIONS IN CORTEX AND HIPPOCAMPUS

皮层和海马体的联合表征

• 批准号: 6539073
• 负责人: JERRY Weeks RUDY
• 金额: $ 21.74万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-10 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6539073
• 关键词: artificial intelligence; autogenic training; behavioral /social science research tag; computational neuroscience; computer simulation; discrimination learning; hippocampus; laboratory rat; learning; mathematical model; memory; neocortex; neural information processing; neurophysiology; psychological reinforcement; startle reaction

DESCRIPTION: (Adapted from the Investigator's Abstract) The goal of this work is to help clarify the contribution of the hippocampus to memory by testing the implications of a recently-developed theoretical framework for understanding the complementary roles of the hippocampus and neocortex in learning and memory. This framework centers around a set of principles derived from computational neural network models, and we have instantiated it in a specific biologically-based model. Many prominent theories of the hippocampus assume that it contributes to memory by storing conjunctive representations of the features that make up a particular experience. However, this idea is too general because there are a number of reports that animals with severe damage to the hippocampus solve problems that require conjunctive representations. The present model recognizes that the cortical system alone can store stimulus conjunctions. However, it is posited that the hippocampal and cortical systems differ along two important dimensions: (a) learning rate-the hippocampal system rapidly stores conjunctions whereas the cortical system learns more slowly, and (b) the task demands under which the two systems are driven to develop conjunctive representations-the hippocampal system has a natural bias to automatically store conjunctions just as a function of the organism sampling the environment, whereas the cortex is not naturally biased to store conjunctions, and only does so when forced to by the demands of a problem (e.g., reinforcement contingencies). As implemented in the present model, these ideas provide a good account of many phenomena in the literature. By comparing rats with damage to the hippocampus and intact rats, and conducting additional simulations, the goal is to evaluate the proposed theoretical framework by testing its implications for: (a) when the hippocampus will contribute to complex nonlinear discrimination problems, (b) understanding how the hippocampus contributes to contextual fear conditioning, (c) the role of the hippocampus in tasks where conjunctions are automatically learned versus those where they must be learned to satisfy the contingencies of reinforcement, and (d) how the hippocampus mediates what some call logical reasoning (transitive inferences). By pursuing these aims, the proposed research will provide a more complete understanding of the role of the hippocampus in memory.

描述：（改编自研究者摘要） 这项工作的目标是帮助澄清海马体的贡献， 通过测试最近发展的理论的影响， 理解海马体的互补作用的框架， 大脑皮层在学习和记忆中的作用这个框架围绕着一组 从计算神经网络模型中得出的原理，我们有 在一个特定的基于生物学的模型中将其实例化。许多著名的理论 海马体中的一部分假设它通过储存连接词来帮助记忆 构成特定体验的特征的表征。但是，在这方面， 这个想法太笼统了，因为有很多报道说， 海马体严重受损的人， 表示。目前的模型认识到， 可以存储刺激连词。然而，据推测，海马 和皮层系统在两个重要方面沿着不同：（a）学习 速度-海马系统快速存储连接，而皮层 系统学习更慢，以及（B）两个系统的任务要求 被驱动发展联合代表-海马系统有一个 自然的偏见，自动存储连接词只是作为一个功能， 有机体采样环境，而皮层不是自然偏见 存储连词，并且只有在被一个 问题（例如，加强应急）。如目前实施的 模型，这些想法提供了一个很好的说明在文献中的许多现象。 通过比较海马损伤大鼠和完整大鼠， 进行额外的模拟，目标是评估拟议的 理论框架，通过测试其影响：（a）当海马 将有助于复杂的非线性判别问题，（B）理解 海马体如何有助于情境恐惧条件反射，（c）作用 在自动学习连词的任务中， 那些必须学习它们以满足强化的偶然性， 以及（d）海马体如何调节所谓的逻辑推理 （transitive inference）。通过追求这些目标，拟议的研究将 对海马体在记忆中的作用有更全面的了解。