Thölke Philipp, Arcand-Lavigne Maxine, Lajnef Tarek, Frenette Sonia, Carrier Julie, Jerbi Karim
Computational and Cognitive Neuroscience Lab (CoCo Lab), Université de Montréal, Montréal, QC, Canada.
Psychology Department, Université de Montréal, Montréal, QC, Canada.
Commun Biol. 2025 Apr 30;8(1):685. doi: 10.1038/s42003-025-08090-z.
Caffeine is the most widely consumed psychoactive stimulant worldwide. Yet important gaps persist in understanding its effects on the brain, especially during sleep. We analyzed sleep electroencephalography (EEG) in 40 subjects, contrasting 200 mg of caffeine against a placebo condition, utilizing inferential statistics and machine learning. We found that caffeine ingestion led to an increase in brain complexity, a widespread flattening of the power spectrum's 1/f-like slope, and a reduction in long-range temporal correlations. Being most prominent during non-rapid eye movement (NREM) sleep, these results suggest that caffeine shifts the brain towards a critical regime and more diverse neural dynamics. Interestingly, this was more pronounced in younger adults (20-27 years) compared to middle-aged participants (41-58 years) during rapid eye movement (REM) sleep, while no significant age effects were observed during NREM. Interpreting these data in the light of modeling and empirical work on EEG-derived measures of excitation-inhibition balance suggests that caffeine promotes a shift in brain dynamics towards increased neural excitation and closer proximity to a critical regime, particularly during NREM sleep.
咖啡因是全球消费最为广泛的精神活性兴奋剂。然而，在理解其对大脑的影响方面，尤其是在睡眠期间，仍存在重大差距。我们对40名受试者的睡眠脑电图（EEG）进行了分析，将200毫克咖啡因与安慰剂对照，运用推断统计学和机器学习方法。我们发现，摄入咖啡因会导致大脑复杂性增加、功率谱的1/f样斜率普遍变平，以及长程时间相关性降低。这些结果在非快速眼动（NREM）睡眠期间最为显著，表明咖啡因使大脑趋向于一种临界状态和更多样化的神经动力学。有趣的是，在快速眼动（REM）睡眠期间，与中年参与者（41 - 58岁）相比，这在年轻成年人（20 - 27岁）中更为明显，而在NREM睡眠期间未观察到显著的年龄效应。根据关于脑电图衍生的兴奋 - 抑制平衡测量的建模和实证研究来解释这些数据表明，咖啡因促进大脑动力学向神经兴奋增加和更接近临界状态转变，特别是在NREM睡眠期间。
