Neuroimaging of Visual Attention in Aging

衰老过程中视觉注意力的神经影像学

• 批准号: 8523733
• 负责人: David J. Madden
• 金额: $ 45.78万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8523733
• 关键词: Address; Adult; Age; Age-Years; Age-associated memory impairment; Aging; Attention; Behavioral; Brain; Brain imaging; Brain region; Central Nervous System Diseases; Cerebrum; Cognition; Cognitive; Communities; Data; Decision Making; Detection; Development; Diagnosis; Diffusion Magnetic Resonance Imaging; Discrimination; Dorsal; Elderly; Exhibits; Foundations; Frequencies; Functional Magnetic Resonance Imaging; Future; Impaired cognition; Individual; Individual Differences; Lead; Literature; Measures; Mediating; Mediator of activation protein; Memory; Modeling; Pathway interactions; Performance; Play; Procedures; Public Health; Relative (related person); Research; Resistance; Rest; Role; Sensory; Signal Transduction; Structure; Visual; Visual attention; age group; age related; base; behavior measurement; cognitive neuroscience; cohort; neuroimaging; neuromechanism; normal aging; relating to nervous system; research study; response; visual search; white matter; young adult

DESCRIPTION (provided by applicant): Although attention has a central role in age-related decline in cognitive abilities, a barrier to progress, in the cognitive neuroscience of aging, is that little is known regarding the age-related differences in brain structure and function that are relevant for attention. This research addresses the issue of age- related differences in visual attention, from two complementary perspectives: age-related differences in the neural mechanisms associated with visual attention, and the relative influence of different aspects of brain structure and function on age-related differences in measures of visual attention. The theoretical framework for this research proposes that age-related differences in behavioral (attentional) performance represent the combined influences of individual differences in several variables: a) the magnitude of task-related regional activation; b) the functional connectivity (FC) associated with the temporal coherence of the fMRI signal; and c) the integrity of white matter pathways. Five experiments are planned that will examine age-related differences in different aspects of visual search and discrimination. Each experiment will contain separate cohorts of healthy, community-dwelling adults from three age groups: 20-39, 40-59, and 60-79 years of age. Across the experiments, the research will address three specific aims. The first aim is to investigate age-related differences in the magnitude and FC of task-related activation. The hypothesis is that age-related differences in activation, within different components of the frontoparietal network, will vary in relation to: the requirement to combine visual features (Experiments 1-2), the selection of relevant features and resistance to attentional capture (Experiments 3-4), and the control of competing responses (Experiment 5). The second aim is to investigate age-related differences in resting-state (intrinsic) FC, in terms of the temporal coherence of the spontaneous, low-frequency fluctuations in the fMRI signal. Four intrinsic FC networks (default mode; dorsal and ventral attentional; visual sensory) will be investigated, with the hypothesis that age-related decline in intrinsic FC will vary in magnitude across the networks. The third aim is to identify the relative influence of task-related activation, FC, and white matter integrity (from DTI), as mediators of age-related differences in cognitive performance. The hypothesis is that although all of the variables will mediate the relation between age and visual attention, individual differences in white matter integrity have a more direct influence on intrinsic FC than on task-related FC. If the research aims are achieved, the results would impact the cognitive neuroscience of aging, by providing a new integration of neural and behavioral data relevant to visual attention. These data, from healthy individuals, is a necessary foundation for the diagnosis and treatment of cognitive impairments.

描述（由申请人提供）：尽管注意力在认知能力与年龄相关的下降中具有核心作用，但在衰老的认知神经科学方面，进步的障碍是，关于与关注有关的年龄相关的大脑结构和功能的差异知之甚少。从两个互补的角度来看，这项研究解决了视觉注意力与年龄相关的问题：与视觉关注相关的神经机制的差异，以及大脑结构的不同方面和功能对年龄相关的视觉关注度量差异的相对影响。这项研究的理论框架提出，行为（注意力）表现与年龄相关的差异代表了几个变量中个体差异的综合影响：a）与任务相关的区域激活的幅度； b）与fMRI信号的时间连贯性相关的功能连通性（FC）； c）白质途径的完整性。计划了五个实验，该实验将检查视觉搜索和歧视不同方面的年龄相关差异。每个实验将包含来自三个年龄段的健康，社区居民成年人的单独人群：20-39、40-59和60-79岁。在整个实验中，研究将解决三个具体目标。第一个目的是研究与任务相关激活的大小和FC中与年龄相关的差异。假设是，在额叶网络的不同组成部分中，与年龄相关的激活差异将与：结合视觉特征（实验1-2），相关特征的选择和对注意力捕获的抵抗（实验3-4）的选择（实验3-4）以及对竞争响应的控制（实验5）的要求（实验5）。第二个目的是根据fMRI信号自发，低频波动的时间连贯性，研究与年龄相关的静息状态（固有）FC的差异。将研究四个固有的FC网络（默认模式；背侧和腹侧注意力；视觉感觉），并假设在整个网络中，与年龄相关的内在FC的下降幅度会有所不同。第三个目的是确定与任务相关的激活，FC和白质完整性（来自DTI）的相对影响，作为认知性能与年龄相关差异的介体。假设是，尽管所有变量都将介导年龄和视觉注意力之间的关系，但白质完整性的个体差异对固有FC的影响比对与任务相关的FC的影响更直接。如果实现了研究目标，则结果将通过提供与视觉注意力相关的神经和行为数据的新整合来影响衰老的认知神经科学。来自健康个体的这些数据是诊断和治疗认知障碍的必要基础。