Neural correlates of cognitive fatigue and bright light treatment in older adults

项目摘要 疲劳几乎是老年人群的普遍经历，也是非常常见的临床主诉。 超过20%的美国人口患有疲劳症，这占10-15万 医生每年都来看我。由于持续的工作负荷、睡眠不足或 疾病显著降低生活质量，损害认知能力，并增加 汽车和工作场所的错误和事故，每年造成数十亿美元的社会成本。老年 人们比年轻人遭受更多的疲劳症状，但神经相关性 潜在的疲劳及其对脑功能的对策很少被研究， 未知使用多模态功能磁共振成像（fMRI），我们成功地 在健康的年轻人和中年人中检查了认知疲劳的神经相关性， 长时间的脑力劳动。我们的数据表明，认知疲劳可能与改变 默认模式网络（DMN）、额顶叶注意网络、丘脑和 基底神经节区然而，考虑到这些人大脑结构和功能的显著变化， 尽管疲劳会影响衰老过程中的大脑网络，但疲劳是否会以同样的方式影响衰老的大脑仍然是未知的。的 拟议的研究将结合联合收割机我们建立的多模态功能磁共振成像方法和验证 疲劳范式，以检查连续脑力负荷后认知疲劳的神经相关因素 N=40例老年人（年龄在55-85岁之间）。我们还建议评估明亮光线的功效 治疗是一种低成本、非药物性和非侵入性的干预措施，用于促进警觉性， 长时间运动后恢复疲劳脑功能和提高运动成绩的潜在对策 老年人的认知负荷。这项研究将测试认知疲劳将是 与DMN、丘脑和额顶叶的静息脑活动和连通性降低相关 网络在老年人，而明亮的光治疗将减少疲劳症状，减轻大脑 这些网络的功能变化。从这项研究中获得的新知识将与 仅用于在连续任务要求后优化人的绩效并提高老年人的安全性 (e.g.,在交通、医疗和安全方面），而且还用于理解和管理疲劳 各种衰老相关疾病的症状（例如，癌症、痴呆症、帕金森病、中风， 创伤性脑损伤）。该项目也有可能产生基于大脑的疲劳生物标志物， 可用于预测个体对连续任务要求的响应以及对光的响应 治疗以减少疲劳和提高性能。

PROJECT SUMMARY Fatigue is nearly a universal experience in the aged population and a very common clinical complaint. More than 20% of the United States population suffers from fatigue, which accounts for 10-15 million doctor visits every year. Cognitive or mental fatigue due to continuous workload, insufficient sleep, or illness significantly reduces quality of life, impairs cognitive performance, and increases the risk of automobile and workplace errors and accidents, at a societal cost of billions of dollars annually. Older people suffer significantly more from fatigue symptoms than younger individuals, yet the neural correlates underlying fatigue and its countermeasures on brain function have rarely been studied and remain largely unknown. Using multimodal functional magnetic resonance imaging (fMRI), we have successfully examined the neural correlates of cognitive fatigue in healthy young and middle aged adults after prolonged mental workload. Our data demonstrate that cognitive fatigue may be associated with altered resting brain function in the default mode network (DMN), frontoparietal attention network, thalamus, and basal ganglia regions. However, given significant structural and functional brain changes in these networks during aging, it remains unknown if fatigue will affect the aged brain in the same manner. The proposed research will combine our established multimodal functional MRI approach and validated fatigue paradigm to examine the neural correlates of cognitive fatigue after continuous mental workload in N=40 older adults (age between 55-85 years). We also propose to evaluate the efficacy of bright light treatment, a low-cost, non-pharmacological, and noninvasive intervention for promoting alertness, as a potential countermeasure for restoring fatigued brain function and improving performance after prolonged cognitive workload in the elderly. This study will test the hypothesis that cognitive fatigue will be associated with reduced resting brain activity and connectivity in the DMN, thalamus, and frontoparietal network in older adults, while bright light treatment will reduce fatigue symptoms by mitigating the brain function changes in these networks. The new knowledge gained from this study will have relevance not only for optimizing human performance and promoting safety of elderly after continuous task requirement (e.g., in transportation, medical care, and security), but also for understanding and managing fatigue symptoms in various aging-related diseases (e.g., cancer, dementia, Parkinson's disease, stroke, and traumatic brain injury). The project also has the potential to yield brain-based biomarkers of fatigue that may be used to predict individual responses to continuous task requirement as well as responses to light treatment for reducing fatigue and improving performance.