EVENT ENCODING IN NAVIGATION AND SPATIAL MEMORY

描述（由申请人提供）：导航能力降低通常与高龄相关，特别是与阿尔茨海默病（AD）相关。导航困难可能对个人的自力更生造成毁灭性的影响，这些问题甚至可能是危险的，特别是在驾驶时。研究表明，这种与年龄有关的困难， 因为他们缺乏通过在环境中旅行来创建结构化的认知地图的能力。在设计应对老年人迷路困难的方法时，迫切需要关于这些心理地图在导航过程中是如何构建的理论。在这里，我们测试一个新的建议，限制如何建立心理地图的导航经验和心理地图的建设如何随着年龄的变化。研究表明，空间表征和空间记忆通常被组织成块;某些位置在记忆中被分组在一起。几个因素，如时间和空间的接近度和环境的显着物理特征已被确定为重要的，在确定什么位置被分块在一起。然而，很少有工作已经做了，以确定具体的认知和神经机制，空间记忆的组织。我们认为，经验的时间分割为情节或事件，是决定空间结构的一个重要因素。 记忆因此，改善时间编码可以改善空间记忆。在这些实验中，参与者将观看演员在特定环境中导航的短的第一人称电影（例如，建筑物）。在某些情况下，参与者会将电影分割成空间区域或事件，而在其他情况下，功能磁成像（fMRI）将用于监测观看电影期间的大脑活动。在观看电影后，将测量导航环境的空间记忆以测试以下假设：1）导航期间的空间和时间分割影响导航空间的后期记忆。2)与年龄相关的空间和时间分割机制的下降与较差的空间记忆有关。3)在老年人中，空间敏感脑区的相位活动被破坏，这种破坏与空间记忆障碍有关。这项研究的成功完成将开辟一套新的认知和神经机制，作为研究人员和临床医生努力解决与年龄相关的导航困难这一重要问题的目标。空间记忆结构的理论动机措施可能被证明是特别有价值的诊断导航困难与早期痴呆症。如果年龄相关的导航困难是由时间分割损伤介导的，这将提供一个新的干预目标。 公共卫生相关性：与正常衰老相关的导航困难，特别是与年龄相关的痴呆症，可能对个人的自立能力造成破坏，这些问题甚至可能是危险的，特别是在驾驶时。这项工作将研究空间记忆的结构是如何确定的，以及随着年龄的增长，该结构的重要方面如何变化。这项研究的成功完成将开辟一套新的认知和神经机制，作为研究人员和临床医生努力解决与年龄相关的导航困难这一重要问题的目标。

DESCRIPTION (provided by applicant): Reduced navigation ability has been associated with advanced age in general and particularly with Alzheimer's disease (AD). Navigation difficulties can be devastating to an individual's self-reliance, and such problems can even be dangerous, particularly while driving. Research suggests that such age related difficulties arise specifically from deficits in the ability to create structured cognitive maps of environments from traveling around in them. Theories of how these mental maps are constructed during navigation are sorely needed to design responses to older adults' difficulties with getting lost. Here we test a novel proposal constraining how mental maps are built up from navigation experience and how mental map construction changes with age. Research suggests that spatial representations and spatial memory in general, are organized into chunks; certain locations are grouped together in memory. Several factors, such as temporal and spatial proximity and salient physical features of the environment have been identified as important in determining what locations get chunked together. However, little work has been done to identify specific cognitive and neural mechanisms by which spatial memory is organized. We propose that temporal segmentation of experience into episodes, or events, is an important factor in determining the structure of spatial memory. Therefore, improving temporal encoding could improve spatial memory. In these experiments, participants will view short first person movies of actors navigating through particular environments (e.g., buildings). In some cases, participants will segment the movies into spatial regions or events, and in others functional magnetic imaging (fMRI) will be used to monitor brain activity during movie viewing. After movie viewing, spatial memory for the navigated environments will be measured to test the following hypotheses: 1) Spatial and temporal segmentation during navigation affects later memory for the navigated space. 2) Age related declines in spatial and temporal segmentation mechanisms are associated with poorer spatial memory. 3) Phasic activity in spatially sensitive brain regions is disrupted in older adult, and this disruption is associated with spatial memory impairment. Successful completion of this research will open up a new set of cognitive and neural mechanisms as targets for researchers and clinicians working to address the important problem of age related navigation difficulty. Theoretically motivated measures of structure in spatial memory may prove particularly valuable for diagnosing navigation difficulties associated with early-stage dementia. If age-related navigating difficulties are mediated by temporal segmentation impairments, this will provide a novel target for intervention. PUBLIC HEALTH RELEVANCE: Navigation difficulties associated with normal aging, and especially with age-related dementia, can be devastating to an individual's self-reliance, and such problems can even be dangerous, particularly while driving. This work will examine how the structure of spatial memory is determined and how important aspects of that structure change as we age. Successful completion of this research will open up a new set of cognitive and neural mechanisms as targets for researchers and clinicians working to address the important problem of age related navigation difficulty.