The effect of cognitive fatigue on prefrontal cortex correlates of neuromuscular fatigue in older women.
The effect of cognitive fatigue on prefrontal cortex correlates of neuromuscular fatigue in older women.
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DOI：
10.1186/s12984-015-0108-3
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发表时间：
2015-12-21
影响因子：
5.1
通讯作者：
Mehta RK
中科院分区：
文献类型：
--
作者：
Shortz AE;Pickens A;Zheng Q;Mehta RK
随着65岁及以上成年人的人口迅速增长，确定与日常生活有关的身体和认知限制至关重要。认知疲劳已被证明对年轻人的神经肌肉功能产生不利影响，但其对老年人神经肌肉疲劳和相关脑功能变化的影响尚不清楚。这项研究的目的是检查认知疲劳对老年妇女神经肌肉疲劳和相关的前额叶皮层（PFC）激活模式的影响。11名年龄较大（75.82（7.4）岁）的女性参加了两次会议，并在60分钟的控制（观看纪录片）和60分钟的认知疲劳（进行Stroop色词和1-Back测试）条件下，以30%的最大随意收缩（MVC）进行间歇性握力练习，直到自愿疲劳。相关指标包括耐力时间、力量损失、PFC活动（使用fNIRS测量）、力量波动、肌肉活动、心血管反应和感知不适。与对照条件相比，参与者在60分钟认知疲劳条件后感到更大的认知疲劳。虽然神经肌肉疲劳的结果（即，耐力时间、力量损失、感觉不适）、力波动和肌肉活动在控制和认知疲劳条件下都是相似的，当与控制条件相比时，观察到认知疲劳条件后神经肌肉疲劳发展期间PFC活动的更大减少。尽管神经肌肉结果相似，但认知疲劳与握力疲劳运动期间PFC激活钝化相关，这可能表明随着年龄的增长，神经适应性在努力保持运动性能。需要通过成像其他运动相关的大脑区域来检查认知疲劳和神经肌肉输出之间的关系，以更好地理解与年龄相关的补偿适应，以执行涉及一定程度的认知需求和体育锻炼的日常任务，特别是当老年人依次经历这些任务时。
As the population of adults aged 65 and above is rapidly growing, it is crucial to identify physical and cognitive limitations pertaining to daily living. Cognitive fatigue has shown to adversely impact neuromuscular function in younger adults, however its impact on neuromuscular fatigue, and associated brain function changes, in older adults is not well understood. The aim of the study was to examine the impact of cognitive fatigue on neuromuscular fatigue and associated prefrontal cortex (PFC) activation patterns in older women. Eleven older (75.82 (7.4) years) females attended two sessions and performed intermittent handgrip exercises at 30 % maximum voluntary contraction (MVC) until voluntary exhaustion after a 60-min control (watching documentary) and 60-min cognitive fatigue (performing Stroop Color Word and 1-Back tests) condition. Dependent measures included endurance time, strength loss, PFC activity (measured using fNIRS), force fluctuations, muscle activity, cardiovascular responses, and perceived discomfort. Participants perceived greater cognitive fatigue after the 60-min cognitive fatigue condition when compared to the control condition. While neuromuscular fatigue outcomes (i.e., endurance time, strength loss, perceived discomfort), force fluctuations, and muscle activity were similar across both the control and cognitive fatigue conditions, greater decrements in PFC activity during neuromuscular fatigue development after the cognitive fatigue condition were observed when compared to the control condition. Despite similar neuromuscular outcomes, cognitive fatigue was associated with blunted PFC activation during the handgrip fatiguing exercise that may be indicative of neural adaptation with aging in an effort to maintain motor performance. Examining the relationship between cognitive fatigue and neuromuscular output by imaging other motor-related brain regions are needed to provide a better understanding of age-related compensatory adaptations to perform daily tasks that involve some levels of cognitive demand and physical exercise, especially when older adults experience them sequentially.