Benkirane Oumaïma, Simor Peter, Mairesse Olivier, Peigneux Philippe
UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, at CRCN-Centre for Research in Cognition and Neurosciences and UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium.
BBCO-Brain, Body and Cognition, Department of Psychology, Faculty of Psychology and Educational Sciences, Vrije Universiteit Brussel, 1050 Brussel, Belgium.
Clocks Sleep. 2024 Oct 22;6(4):602-618. doi: 10.3390/clockssleep6040041.
Cognitive fatigue (CF) is a critical factor affecting performance and well-being. It can be altered in suboptimal sleep quality conditions, e.g., in patients suffering from obstructive sleep apnea who experience both intermittent hypoxia and sleep fragmentation (SF). Understanding the neurophysiological basis of SF in healthy individuals can provide insights to improve cognitive functioning in disrupted sleep conditions. In this electroencephalographical (EEG) study, we investigated in 16 healthy young participants the impact of experimentally induced SF on the neurophysiological correlates of CF measured before, during, and after practice on the TloadDback, a working memory task tailored to each individual's maximal cognitive resources. The participants spent three consecutive nights in the laboratory two times, once in an undisrupted sleep (UdS) condition and once in an SF condition induced by non-awakening auditory stimulations, counterbalanced and performed the TloadDback task both in a high (HCL) and a low (LCL) cognitive load condition. EEG activity was recorded during wakefulness in the 5 min resting state immediately before and after, as well as during the 16 min of the TloadDback task practice. In the high cognitive load under a sleep-fragmentation (HCL/SF) condition, high beta power increased during the TloadDback, indicating heightened cognitive effort, and the beta and alpha power increased in the post- vs. pre-task resting state, suggesting a relaxation rebound. In the low cognitive load/undisturbed sleep (LCL/UdS) condition, low beta activity increased, suggesting a relaxed focus, as well as mid beta activity associated with active thinking. These findings highlight the dynamic impact of SF on the neurophysiological correlates of CF and underscore the importance of sleep quality and continuity to maintain optimal cognitive functioning.
认知疲劳（CF）是影响表现和幸福感的关键因素。在睡眠质量欠佳的情况下，例如在患有阻塞性睡眠呼吸暂停的患者中，认知疲劳会发生改变，这些患者会经历间歇性缺氧和睡眠片段化（SF）。了解健康个体中睡眠片段化的神经生理基础可以为改善睡眠中断情况下的认知功能提供见解。在这项脑电图（EEG）研究中，我们对16名健康的年轻参与者进行了调查，研究了实验诱导的睡眠片段化对认知疲劳的神经生理相关性的影响，这些相关性在针对每个个体最大认知资源量身定制的工作记忆任务TloadDback的练习前、练习期间和练习后进行测量。参与者在实验室连续度过三个晚上，共两次，一次处于无干扰睡眠（UdS）状态，一次处于由非唤醒听觉刺激诱导的睡眠片段化状态，两种状态相互平衡，并在高（HCL）和低（LCL）认知负荷条件下都执行TloadDback任务。在TloadDback任务练习前、练习后的5分钟静息状态以及练习期间的16分钟内，记录清醒时的脑电图活动。在睡眠片段化（HCL/SF）条件下的高认知负荷中，TloadDback期间高β功率增加，表明认知努力增强，并且在任务后与任务前的静息状态相比，β和α功率增加，表明存在放松反弹。在低认知负荷/无干扰睡眠（LCL/UdS）条件下，低β活动增加，表明注意力放松，以及与积极思考相关的中β活动增加。这些发现突出了睡眠片段化对认知疲劳神经生理相关性的动态影响，并强调了睡眠质量和连续性对维持最佳认知功能的重要性。
