US-German Collaboration: Toward a quantitative understanding of navigational deficits in aging humans

美德合作：定量理解老年人的导航缺陷

• 批准号: 1929607
• 负责人: Ila Fiete
• 金额: $ 1.63万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929607&HistoricalAwards=false
• 关键词: US; German; Collaboration; Toward; quantitative

The goal of this project is to combine computational modeling with behavioral and neuroimaging studies to characterize the mechanisms of navigational abilities in humans and understand how they decline with age. The PIs will focus on an important navigational circuit in mammals, which consists of the hippocampus and associated areas, and includes grid cells of the entorhinal cortex as well as place cells. Place cells have highly location-specific responses, turning on at one location in an environment and firing little elsewhere; grid cells by contrast fire at multiple locations within an environment, with periodically separated activity blobs in a striking triangular lattice pattern. Studies in rodents have detailed the properties of grid and place cells, and led to neural network models whose additional predictions have often been borne out by single-unit neuron recordings. However, much less is known about grid cells and place cells in humans, and the nature of interactions between different parts of the navigation circuit remains unclear, in rodents and humans. In this project, the PIs bring to bear virtual-reality-based behavioral experiments, ultra-high-resolution fMRI recordings during virtual navigation, and neural network modeling, to better understand the circuit for spatial navigation in humans. The PIs plan a three-pronged approach to these questions. The first is to characterize phenomenologically the characteristic errors made by humans, through navigation environments with and without accurate external landmark cues, and under other externally varying conditions, in aged and non-aged subjects. The second is to employ neural network models of grid cells, to model the network parameters that could give rise to the observed deficits, and in turn test the predictions of these models with the neuroimaging experiments. The experimental setup will permit systematic variation in the fidelity of external sensory cues, to probe the relative contributions of the complementary computations of dead-reckoning (path integration) versus landmark-based navigation, and uncover their potential neural substrates in humans. The results will help to develop models of how parallel streams of spatial information are combined and processed across brain areas to aid in navigation. The third component is to develop accurate algorithms for extracting spatial information from high-resolution fMRI data from regions and sub-regions of the entorhinal-hippocampal complex. The aim is to map the distribution of location information across areas and learn where it is most compromised in old age.This award is being co-funded by NSF's Office of the Director, International Science and Engineering. A companion project is being funded by the German Ministry of Education and Research (BMBF).

该项目的目标是将联合收割机计算建模与行为和神经成像研究相结合，以表征人类导航能力的机制，并了解它们如何随着年龄的增长而下降。PI将集中在哺乳动物中的一个重要的导航电路，它由海马和相关区域组成，包括内嗅皮层的网格细胞以及位置细胞。位置细胞具有高度的位置特异性反应，在环境中的一个位置打开，在其他地方几乎没有放电;相比之下，网格细胞在环境中的多个位置放电，周期性地分离活动斑点，形成引人注目的三角形网格模式。对啮齿动物的研究已经详细描述了网格和位置细胞的特性，并导致了神经网络模型，其额外的预测通常由单单位神经元记录证实。然而，对人类的网格细胞和位置细胞知之甚少，在啮齿动物和人类中，导航电路不同部分之间的相互作用的性质仍然不清楚。在这个项目中，PI带来了基于虚拟现实的行为实验，虚拟导航期间的超高分辨率fMRI记录和神经网络建模，以更好地了解人类空间导航的电路。PI计划三管齐下解决这些问题。第一个是表征人类的特征错误，通过导航环境与准确的外部地标线索，并在其他外部变化的条件下，在老年和非老年受试者。第二种是采用网格细胞的神经网络模型，对可能引起所观察到的缺陷的网络参数进行建模，并反过来用神经成像实验来测试这些模型的预测。实验设置将允许外部感觉线索的保真度的系统变化，以探测航位推算（路径整合）与基于地标的导航的互补计算的相对贡献，并揭示其在人类中的潜在神经基板。研究结果将有助于开发空间信息并行流如何在大脑区域之间组合和处理的模型，以帮助导航。第三部分是开发精确的算法，从高分辨率的fMRI数据中提取空间信息的区域和子区域的内鼻-海马复合体。该奖项由美国国家科学基金会国际科学与工程主任办公室共同资助。 德国教育和研究部（BMBF）正在资助一个配套项目。