Zhao Chenyao, Li Nuoyi, Yi Xiangwei, Wang Xiao, He Ying, Shen Haiping, Lin Yandan
Department of Light Sources and Illuminating Engineering, School of Information Science and Technology, Fudan University, Shanghai, China.
Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, China.
J Sleep Res. 2025 Aug;34(4):e14450. doi: 10.1111/jsr.14450. Epub 2025 Jan 12.
The '6-h on/6-h off' shift pattern could potentially disrupt the physiological rhythms and cognitive performance of seafarers, attributed to its shorter and more frequent shifts. Conversely, light exposure has been demonstrated to enhance cognitive abilities and synchronise physiological processes. Therefore, we studied the fatigue, cognition, sleep and rhythm of seafarers with different shifts to determine how light can benefit their performance. A total of 16 seafarers participated in a 2 × 2 crossover study, which involved two shift types (Morning-Evening and Day-Night) and two lighting conditions (static lighting and dynamic lighting). Sleepiness, cognition and fatigue were assessed every 2 h during '6-h on' period, using the Karolinska Sleepiness Scale, psychomotor vigilance task, critical flicker frequency and visual analogue scale for fatigue. Sleep was monitored during '6-h off' period, core body temperature was continuously tracked for rhythm throughout the shift protocol. For the Day-Night shift, the static mode with stable higher illuminance than dynamic lighting significantly reduced sleepiness (p = 0.01), objective fatigue (p = 0.001), subjective fatigue (fatigue level [p = 0.004] and visual fatigue [p = 0.001]) during the night period, while increasing sleep duration during the day (6:00 a.m. to 12:00 p.m.) and delaying the rhythm. For the Morning-Evening shift, dynamic lighting with lower illuminance significantly increased sleep duration during the night (12:00 a.m. to 6:00 a.m.) without causing a significant difference in performance. Overall, static lighting is more suitable for Day-Night shift seafarers due to lower sleepiness, fatigue and longer daytime sleep duration, while dynamic lighting is more suitable for Morning-Evening shift seafarers due to longer night-time sleep duration. Therefore, different lighting patterns should be adopted for seafarers during different shifts.
“6小时工作/6小时休息”的轮班模式可能会扰乱海员的生理节律和认知表现，原因在于其轮班时间更短且更频繁。相反，已证明光照可增强认知能力并使生理过程同步。因此，我们研究了不同轮班方式下海员的疲劳、认知、睡眠和节律情况，以确定光照如何有益于他们的工作表现。共有16名海员参与了一项2×2交叉研究，该研究涉及两种轮班类型（早班-晚班和日班-夜班）以及两种光照条件（静态光照和动态光照）。在“6小时工作”期间，每隔2小时使用卡罗林斯卡嗜睡量表、心理运动警觉任务、临界闪烁频率和疲劳视觉模拟量表对嗜睡、认知和疲劳进行评估。在“6小时休息”期间监测睡眠情况，在整个轮班过程中持续跟踪核心体温以了解节律。对于日班-夜班轮班，静态模式下的照度稳定且高于动态光照，这显著降低了夜间的嗜睡感（p = 0.01）、客观疲劳感（p = 0.001）、主观疲劳感（疲劳程度[p = 0.004]和视觉疲劳[p = 0.001]），同时增加了白天（上午6点至中午12点）的睡眠时间并使节律延迟。对于早班-晚班轮班，照度较低的动态光照显著增加了夜间（凌晨12点至上午6点）的睡眠时间，且在工作表现上没有造成显著差异。总体而言，静态光照因嗜睡感和疲劳感较低以及白天睡眠时间更长，更适合日班-夜班轮班的海员，而动态光照因夜间睡眠时间更长，更适合早班-晚班轮班的海员。因此，应针对不同轮班的海员采用不同的光照模式。
