Höhn Christopher, Hahn Michael A, Gruber Georg, Pletzer Belinda, Cajochen Christian, Hoedlmoser Kerstin
Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, Paris Lodron University of Salzburg, 5020 Salzburg, Austria.
Centre for Cognitive Neuroscience Salzburg (CCNS), Paris Lodron University of Salzburg, 5020 Salzburg, Austria.
Brain Commun. 2024 May 17;6(3):fcae173. doi: 10.1093/braincomms/fcae173. eCollection 2024.
Exposure to short-wavelength light before bedtime is known to disrupt nocturnal melatonin secretion and can impair subsequent sleep. However, while it has been demonstrated that older adults are less affected by short-wavelength light, there is limited research exploring differences between adolescents and young adults. Furthermore, it remains unclear whether the effects of evening short-wavelength light on sleep architecture extend to sleep-related processes, such as declarative memory consolidation. Here, we recorded polysomnography from 33 male adolescents (15.42 ± 0.97 years) and 35 male young adults (21.51 ± 2.06 years) in a within-subject design during three different nights to investigate the impact of reading for 90 min either on a smartphone with or without a blue-light filter or from a printed book. We measured subjective sleepiness, melatonin secretion, sleep physiology and sleep-dependent memory consolidation. While subjective sleepiness remained unaffected, we observed a significant melatonin attenuation effect in both age groups immediately after reading on the smartphone without a blue-light filter. Interestingly, adolescents fully recovered from the melatonin attenuation in the following 50 min before bedtime, whereas adults still, at bedtime, exhibited significantly reduced melatonin levels. Sleep-dependent memory consolidation and the coupling between sleep spindles and slow oscillations were not affected by short-wavelength light in both age groups. Nevertheless, adults showed a reduction in N3 sleep during the first night quarter. In summary, avoiding smartphone use in the last hour before bedtime is advisable for adolescents and young adults to prevent sleep disturbances. Our research empirically supports general sleep hygiene advice and can inform future recommendations regarding the use of smartphones and other screen-based devices before bedtime.
已知睡前接触短波长光会扰乱夜间褪黑素分泌，并可能损害随后的睡眠。然而，虽然已经证明老年人受短波长光的影响较小，但探索青少年和年轻人之间差异的研究有限。此外，尚不清楚夜间短波长光对睡眠结构的影响是否会扩展到与睡眠相关的过程，如陈述性记忆巩固。在此，我们采用受试者内设计，在三个不同的夜晚，对33名男性青少年（15.42±0.97岁）和35名男性年轻人（21.51±2.06岁）进行多导睡眠图记录，以研究在有或没有蓝光滤镜的智能手机上阅读90分钟或阅读纸质书的影响。我们测量了主观嗜睡、褪黑素分泌、睡眠生理和睡眠依赖性记忆巩固。虽然主观嗜睡没有受到影响，但我们观察到，在没有蓝光滤镜的智能手机上阅读后，两个年龄组的褪黑素均立即出现显著衰减效应。有趣的是，青少年在睡前接下来的50分钟内从褪黑素衰减中完全恢复，而成年人在就寝时褪黑素水平仍显著降低。两个年龄组的睡眠依赖性记忆巩固以及睡眠纺锤波与慢波振荡之间的耦合均未受到短波长光的影响。然而，成年人在第一个夜间时段的N3睡眠减少。总之，建议青少年和年轻人在睡前最后一小时避免使用智能手机，以防止睡眠障碍。我们的研究从实证上支持了一般的睡眠卫生建议，并可为未来关于睡前使用智能手机和其他基于屏幕的设备的建议提供参考。
