Yetish Gandhi, Kaplan Hillard, Gurven Michael, Wood Brian, Pontzer Herman, Manger Paul R, Wilson Charles, McGregor Ronald, Siegel Jerome M
Department of Anthropology, University of New Mexico, MSC01-1040, Albuquerque, NM 87131, USA.
Department of Anthropology, University of California, Santa Barbara, 1210 Cheadle Hall, Santa Barbara, CA 93106, USA.
Curr Biol. 2015 Nov 2;25(21):2862-2868. doi: 10.1016/j.cub.2015.09.046. Epub 2015 Oct 17.
How did humans sleep before the modern era? Because the tools to measure sleep under natural conditions were developed long after the invention of the electric devices suspected of delaying and reducing sleep, we investigated sleep in three preindustrial societies [1-3]. We find that all three show similar sleep organization, suggesting that they express core human sleep patterns, most likely characteristic of pre-modern era Homo sapiens. Sleep periods, the times from onset to offset, averaged 6.9-8.5 hr, with sleep durations of 5.7-7.1 hr, amounts near the low end of those industrial societies [4-7]. There was a difference of nearly 1 hr between summer and winter sleep. Daily variation in sleep duration was strongly linked to time of onset, rather than offset. None of these groups began sleep near sunset, onset occurring, on average, 3.3 hr after sunset. Awakening was usually before sunrise. The sleep period consistently occurred during the nighttime period of falling environmental temperature, was not interrupted by extended periods of waking, and terminated, with vasoconstriction, near the nadir of daily ambient temperature. The daily cycle of temperature change, largely eliminated from modern sleep environments, may be a potent natural regulator of sleep. Light exposure was maximal in the morning and greatly decreased at noon, indicating that all three groups seek shade at midday and that light activation of the suprachiasmatic nucleus is maximal in the morning. Napping occurred on <7% of days in winter and <22% of days in summer. Mimicking aspects of the natural environment might be effective in treating certain modern sleep disorders.
在现代社会之前，人类是如何睡眠的？由于在那些被怀疑会延迟和减少睡眠的电子设备发明很久之后，用于在自然条件下测量睡眠的工具才得以开发，我们对三个前工业化社会的睡眠情况进行了调查[1 - 3]。我们发现这三个社会都呈现出相似的睡眠模式，这表明它们体现了人类核心的睡眠模式，很可能是现代智人在现代之前那个时代的特征。睡眠时间，即从入睡到醒来的时长，平均为6.9 - 8.5小时，睡眠持续时间为5.7 - 7.1小时，这些数值接近工业化社会的下限[4 - 7]。夏季和冬季的睡眠时间相差近1小时。睡眠持续时间的每日变化与入睡时间密切相关，而非醒来时间。这些群体中没有一个在日落后不久就开始睡觉，平均入睡时间是在日落后3.3小时。醒来通常在日出之前。睡眠时段始终出现在环境温度下降的夜间，不会被长时间的清醒打断，并且随着血管收缩，在每日环境温度最低点附近结束。温度变化的每日周期在现代睡眠环境中基本被消除了，它可能是睡眠的一个强大的自然调节因素。早晨的光照强度最大，中午大幅下降，这表明这三个群体在中午都会寻找阴凉处，并且视交叉上核的光激活在早晨最为强烈。冬季小睡的天数占比不到7%，夏季不到22%。模仿自然环境的某些方面可能对治疗某些现代睡眠障碍有效。
