Wüst Larissa N, Cajochen Christian, Lasauskaite Ruta
Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland.
Research Cluster Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland.
Neurobiol Sleep Circadian Rhythms. 2025 May 9;18:100125. doi: 10.1016/j.nbscr.2025.100125. eCollection 2025 May.
A chronotype is defined as a preference for certain behaviours (e.g., sleep and wake) to occur at specific times of day. It is therefore also temporally linked with cognitive performance across the day. In an exploratory analysis, we sought to find associations between chronotypes determined from self-reported habitual sleep timing and from salivary melatonin onset with mental effort during a 2-back working memory task. Mental effort was operationalized as sympathetic beta-adrenergic impact on the heart, which is best reflected by the cardiac pre-ejection period (PEP) and also influences systolic blood pressure (SBP). Each participant underwent two experimental sessions in the morning: once after sleeping for 8 h and once after sleeping for 5 h the night before. To determine the timing of evening melatonin onset, participants took saliva samples at hourly intervals at home in the evening, prior to their experimental sessions. Chronotypes were determined using reported sleep times from the Munich Chronotype Questionnaire and average melatonin onset during both sleep conditions. Based on this, participants were grouped into early, intermediate, or late types. Neither alertness ( = 0.019), perceived task demand ( = 0.008), nor SBP response ( = 0.268) were credibly impacted by sleep-time derived chronotype, while the association with PEP response ( = 0.631) during a cognitive challenge in the morning was inconclusive. Similarly, the timing of evening melatonin onset did not affect alertness ( = 0.003), perceived task demand ( = 0.006), or PEP or SBP response (PEP: = 0.232, SBP: = 0.263) during the cognitive challenge. Our data shows no impact of chronotypes on effort-related cardiovascular response during a cognitive challenge in the morning, which was scheduled according to habitual sleep times.
昼夜节律类型被定义为对某些行为（如睡眠和觉醒）在一天中特定时间发生的偏好。因此，它在时间上也与一天中的认知表现相关联。在一项探索性分析中，我们试图找出根据自我报告的习惯性睡眠时间和唾液褪黑素开始分泌时间确定的昼夜节律类型与在2-回溯工作记忆任务中的脑力活动之间的关联。脑力活动通过交感神经β-肾上腺素能对心脏的影响来衡量，这最好通过心脏射血前期（PEP）来反映，并且还会影响收缩压（SBP）。每位参与者在上午进行两次实验：一次是在前一晚睡了8小时后，一次是在前一晚睡了5小时后。为了确定夜间褪黑素开始分泌的时间，参与者在实验前的晚上在家中每隔一小时采集一次唾液样本。昼夜节律类型根据慕尼黑昼夜节律问卷报告的睡眠时间和两种睡眠条件下的平均褪黑素开始分泌时间来确定。据此，参与者被分为早起型、中间型或晚睡型。睡眠时间衍生的昼夜节律类型对警觉性（P = 0.019）、感知到的任务需求（P = 0.008）或SBP反应（P = 0.268）均无显著影响，而在上午的认知挑战中与PEP反应的关联（P = 0.631）尚无定论。同样，夜间褪黑素开始分泌的时间在认知挑战期间对警觉性（P = 0.003）、感知到的任务需求（P = 0.006）或PEP或SBP反应（PEP：P = 0.232，SBP：P = 0.263）也没有影响。我们的数据表明，根据习惯性睡眠时间安排的上午认知挑战中，昼夜节律类型对与努力相关的心血管反应没有影响。
