Exploring the content of human medial temporal lobe representations and their contributions to cognition

记忆是日常生活的中心部分，在塑造我们的个人身份方面起着至关重要的作用。因此，理解大脑如何处理记忆以及为什么我们的记忆会失败，是神经科学的一个基本目标。一个长期存在的理论是，一组被统称为内侧颞叶（MTL）的大脑结构只负责处理长期记忆，有效地充当了一个专用的长期记忆系统。然而，最近的研究挑战了这一观点，并证明，在某些情况下，MTL也参与其他认知领域，包括感知、短期记忆、想象和决策。目前的研究计划旨在考虑到这些发现，并发展一个理论框架，通过这个框架，MTL的看似广泛的功能可以被理解。具体地说，这项工作将建立在MTL的具象视图上，这表明最好是根据它所代表的信息类型来理解MTL，而不是根据它所负责的过程类型来理解MTL。一种说法是，不同的MTL结构负责表示不同类型的信息，如空间场景和物体，每当我们使用这些信息时，就会调用这些表示，而不考虑记忆、感知或想象等认知过程。通过对神经系统健康的参与者和因MTL损伤而出现记忆问题的个体的行为和功能神经影像学研究，本研究将通过以下方式发展表征观点：(1)对MTL表征的内容提供新的见解：MTL表征中包含的对象和场景信息以及我们是否可以检查这些表征是什么样子的？(2)揭示MTL表征对记忆的贡献，特别是它们在解决记忆干扰中的作用；MTL表征如何帮助我们区分相似的记忆？(3)理解关于时间的信息是如何被纳入MTL表征的？ MTL表征如何使我们记住过去事件发生的时间和时间？最后(4)阐明MTL表征在想象中的作用MTL表征如何促进我们的想象？这项工作的发现将会修正关于MTL功能的传统观念，并在此过程中改变我们对大脑中记忆处理的理解，以及记忆和其他认知过程之间的相互作用。这些知识将对加拿大和国际上对大脑和认知之间关系感兴趣的研究产生影响，并且从长远来看，也可能涉及以记忆障碍为症状的医疗条件。

Memory is a central part of everyday life and plays a critical role in shaping our personal identity. It is an essential goal of neuroscience, therefore, to understand how the brain processes memories and why our memories can fail. One long-standing theory is that a group of brain structures, collectively named the medial temporal lobe (MTL), are responsible for processing long-term memory only, effectively serving as a dedicated long-term memory system'. Recent research has, however, challenged this idea, and demonstrated that, in some circumstances, the MTL is also involved in other cognitive domains, including perception, short-term memory, imagination, and decision-making. The current research proposal aims to take account of these findings and develop a theoretical framework by which the MTL's seemingly wide range of functions can be understood. Specifically, this work will build on a representational view of the MTL, which suggests that it is best to understand the MTL according to the type of information that it represents rather than the type of processes that it is responsible for. One suggestion is that different MTL structures are responsible for representing different types of information such as spatial scenes and objects, and that these representations are called upon whenever we make use of this information, irrespective of the cognitive process such as memory, perception, or imagination. Using a combination of behavioural and functional neuroimaging studies in neurologically healthy participants and individuals with memory problems due to MTL damage, this proposal will develop the representational view by: (1) Providing new insight into the content of MTL representations what object and scene information is contained in MTL representations and can we examine what these representations look like?; (2) Revealing how MTL representations contribute to memory, in particular, their role in resolving memory interference how do MTL representations help us to differentiate similar memories?; (3) Understanding how information about time is incorporated into MTL representations how do MTL representations enable us to remember when and for how long a past event happened?; and finally (4) Shedding light on the role of MTL representations in imagination how do MTL representations contribute to our imagination? The findings from this work will revise traditional conceptions of what the MTL does and in doing so, change our understanding of memory processing in the brain, and the interaction between memory and other cognitive processes. This knowledge will have an impact on research that is interested in the relationship between the brain and cognition in Canada and internationally, and in the long-term, may also speak to medical conditions in which memory impairment is a symptom.