Neural mechanisms underlying recognition memory

识别记忆背后的神经机制

• 批准号: RGPIN-2014-05959
• 负责人: Barense, Morgan
• 金额: $ 2.91万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=687894
• 关键词: Neural; mechanisms; underlying; recognition; memory

The overarching goal of the proposed research is to understand how the brain supports memory. It is well-established that long-term memory relies on a set of heavily interconnected structures deep inside the brain that make up what is called the medial temporal lobe (MTL). Most memory researchers believe that these structures in the MTL form a system that is solely dedicated to long-term memory, meaning that these structures have no role in any other cognitive processes such as perception, attention, or working memory. This view is consistent with a popular paradigm in cognitive neuroscience, in which the brain is understood in terms of neatly segregated regions or cognitive modules that are each responsible for different broad psychological functions. Within this framework, it is argued that separate brain systems account for distinct cognitive processes, like "long-term memory," "working memory," or "perception." The proposed research will suggest that this view is neither the most parsimonious nor the most compelling account of the data. Although it is clear that the structures in the MTL are essential for memory, recent findings indicate that these MTL structures do, in addition, play a critical role in perception - a finding that is fundamentally incompatible with the notion of a dedicated MTL memory system specifically, or cognitive modules more generally.**In contrast to a modular view of memory, the proposed research will use neuropsychological and neuroimaging techniques to demonstrate that the functions of brain regions can be better understood in terms of the types of information they represent and the computations they perform. This research will suggest that the MTL should be considered as belonging to the ventral visual stream, a continuous hierarchy of regions that gradually increase in the complexity of information that they process. We propose that whereas regions lower down in the ventral visual stream are responsible for representing the simpler features that make up objects, the perirhinal cortex (PRC) - a key structure of what is currently thought to be the MTL memory system - sits at the peak of this ventral visual stream hierarchy. We argue that a critical function of the PRC is to represent the complex combinations of features that comprise whole objects, and will demonstrate that these complex "object-level" PRC representations are what allow us to make fine-grained distinctions between objects that have similar features. Importantly, we will show that the loss of this ability to discriminate between visually similar objects leads not to memory loss, as is commonly assumed, but rather to a paradoxical false memory for objects that were never seen before. **This project stands to redefine current conceptions of memory by shifting the focus away from explaining functions in terms of specialized cognitive modules (e.g., for long-term memory or perception), and instead towards explaining cognitive processes in terms of how the underlying information is represented in the brain. In addition, through the use of convergent techniques - behavioural studies using modern cognitive paradigms and state-of-the-art neuroimaging - this project will provide exceptional research training opportunities that will strengthen Canada's knowledge-based economy.

拟议研究的总体目标是了解大脑如何支持记忆。众所周知，长期记忆依赖于大脑深处一组紧密相连的结构，这些结构构成了所谓的内侧颞叶（MTL）。大多数记忆研究人员认为，MTL 中的这些结构形成了一个专门用于长期记忆的系统，这意味着这些结构在任何其他认知过程（例如感知、注意力或工作记忆）中没有任何作用。这种观点与认知神经科学中的流行范式一致，其中大脑被理解为整齐隔离的区域或认知模块，每个区域或认知模块负责不同的广泛心理功能。在这个框架内，有人认为不同的大脑系统负责不同的认知过程，例如“长期记忆”、“工作记忆”或“感知”。拟议的研究表明，这种观点既不是最节俭的，也不是最令人信服的数据解释。尽管很明显 MTL 中的结构对于记忆至关重要，但最近的研究结果表明，这些 MTL 结构确实在感知中发挥着关键作用——这一发现从根本上与专门的 MTL 记忆系统或更一般的认知模块的概念不相容。**与记忆的模块化观点相反，拟议的研究将使用神经心理学和神经影像技术来证明 通过大脑区域所代表的信息类型和执行的计算，可以更好地理解大脑区域的功能。这项研究表明，MTL 应被视为属于腹侧视觉流，这是一个连续的区域层次结构，其处理的信息的复杂性逐渐增加。我们认为，虽然腹侧视觉流中较低的区域负责表示构成物体的更简单的特征，但嗅周皮层（PRC）——目前被认为是 MTL 记忆系统的关键结构——位于腹侧视觉流层次结构的顶部。我们认为 PRC 的一个关键功能是表示构成整个对象的特征的复杂组合，并将证明这些复杂的“对象级”PRC 表示使我们能够在具有相似特征的对象之间进行细粒度的区分。重要的是，我们将证明，区分视觉相似物体的能力的丧失不会像通常假设的那样导致记忆丧失，而是会导致对以前从未见过的物体产生矛盾的错误记忆。 **该项目将重新定义当前的记忆概念，将焦点从专门认知模块（例如，长期记忆或感知）的功能解释转移到根据底层信息如何在大脑中表示来解释认知过程。此外，通过使用融合技术——利用现代认知范式和最先进的神经影像进行行为研究——该项目将提供特殊的研究培训机会，从而加强加拿大的知识型经济。