Slow-wave sleep and executive network function in older adults

 认知障碍影响高达36%的65岁以上人口，并决定一个人是否可以独立生活和工作能力在老年人。65岁以后，痴呆症的发病率呈指数级增长。识别认知障碍的可改变因素以及减轻认知缺陷的廉价，安全的方法是研究和临床实践的关键优先事项。赤字 认知能力会受到老年人睡眠变化的影响。现有的研究表明，睡眠不足对年轻人的认知和大脑功能造成严重后果。这就提出了一个问题，即老年人常见的睡眠不足是否会导致老年人普遍存在的认知缺陷。随着年龄的增长而衰退的认知过程依赖于前额叶皮层（PFC），即执行功能，对睡眠效率和睡眠深度的个体差异最敏感。奇怪的是，习惯性总睡眠时间很少与老年人的执行功能有关。事实上，很长的总睡眠时间通常与 认知能力差和一般健康状况差。因此，睡眠限制不会对老年人的认知产生与年轻人相同的负面影响。这就提出了一个问题，即更深、更巩固的睡眠是否对老年人更好。可能有一个适度的“理想”睡眠范围，可以优化睡眠深度，以优化老年人的认知和大脑功能。这项研究的目的是通过限制睡眠时间，从行为上增加老年人睡眠深度的生理指标（非REM慢波活动），以研究其对执行功能和相应功能性大脑网络连接的积极影响。这项研究的重点是确定睡眠深度对执行功能和相应网络的影响是否最大。这项研究将查明睡眠促进认知健康的系统水平途径。从广义上讲，它将有助于我们未来发展睡眠干预措施，以改善认知和我们对促进认知健康和大脑健康的可改变健康因素的理解。

 DESCRIPTION (provided by applicant): Cognitive impairments affect up to 36% of the population over age 65 and determine whether an individual may live independently and work competently in older adulthood. After 65, the incidence of dementia increases exponentially. Identifying modifiable contributors to cognitive impairment and inexpensive, safe ways to mitigate cognitive deficits are critical priorities for research and clinical practice. Deficits in cognition are paralleled by changes in sleep in older adulthood. Existing research demonstrates severe consequences of sleep loss on cognition and brain function in young adults. This raises the question of whether sleep deficits common in aging contribute to cognitive deficits prevalent in older adulthood. Cognitive processes that decline with age and depend on the prefrontal cortex (PFC), i.e. executive functions, are most sensitive to individual differences sleep efficiency and sleep depth. Paradoxically, habitual total sleep time is rarely associated with executive function in older adults. In fact, very long total sleep time is commonly associated with poorer cognition and general health. Consequently, sleep restriction does not negatively affect cognition in older adults to the same extent as young adults. This raises the question of whether deeper, more consolidated sleep is better for older adults. There may be a moderate "ideal" sleep range that optimizes sleep depth to optimize cognition and brain function in older adults. The aim of the proposed study is to behaviorally increase physiological measures of sleep depth (non-REM slow-wave activity) in older adults through time-in-bed restriction, to examine its positive effects on executive function and corresponding functional brain network connectivity. This study's focus is to determine whether effects of sleep depth are greatest for executive functions and corresponding networks. This study will pinpoint systems-level pathways through which sleep promotes cognitive fitness. Broadly, it will contribute to our future development of sleep interventions to improve cognition and our understanding of modifiable health factors that promote cognitive fitness and brain health.