We've all heard advice about good sleep hygiene. No phones or caffeine before bed, and make sure that we get a good eight hours' rest. But is this the best sleep pattern, or have we just been led to it by modern life?

我们都听过关于良好睡眠习惯的建议：睡前不要玩手机或摄入咖啡因，并且要确保有充足的八小时睡眠。但这真的是最好的睡眠模式吗？还是说，我们只是被现代生活方式引导成这样的？

Artificial light in our houses and streets means that we no longer have to go to bed at sundown. Having a job to go to at a set time in the morning can be the main determining factor on when we decide to rouse ourselves. In past centuries, the time of sunset and sunrise had a much bigger impact on people's days. Historical studies have shown that in many parts of the world it was common for people to sleep in two sections, from dusk until around 11 and then from one in the morning until sunrise. This segmented or biphasal sleep pattern is referred to as far back in history as ancient Greece.

家中和街道上的人工照明，使我们不再需要在日落时就上床睡觉。而早晨必须在固定时间上班，往往成为我们决定何时起床的主要因素。在过去的几个世纪里，日落和日出的时间对人们的日常生活影响要大得多。历史研究表明，在世界许多地区，人们普遍采取分两段的睡眠方式：从黄昏睡到大约晚上十一点，再从凌晨一点睡到日出。这种分段式或“双相睡眠”模式，早在古希腊时期的历史记载中就已经出现。

So, if modern sleep patterns are in some part due to modern lifestyles and technologies, could segmented sleep patterns be more natural? Some studies suggest that they are. The circadian rhythms that determine when we start to feel drowsy are greatly affected by light. Study participants subjected to 14 hours of complete darkness a day started to develop a biphasal sleeping pattern. As recently as 2017, similar patterns have also been seen in some communities in rural Madagascar that do not have access to electric light.

那么，如果现代的睡眠模式在某种程度上是现代生活方式和技术造成的，分段睡眠是否反而更自然呢？一些研究表明，答案是肯定的。决定我们何时开始感到困倦的昼夜节律，会受到光线的强烈影响。研究中，每天处在十四小时完全黑暗环境下的参与者，开始逐渐形成双相睡眠模式。甚至就在2017年，在马达加斯加一些无法使用电灯的农村社区中，也观察到了类似的睡眠模式。

They may be more natural, but are these sleeping patterns healthier? Experts caution that the small number of studies carried out means that the risks and benefits of segmented sleeping are not well understood. Nevertheless, some people have found it to be a useful way to find time to be creative. Psychologist Gregg Jacobs suggests that the period of time that people used to spend awake in past centuries could have been used to regulate stress. Other experts remind us that many people find that they wake in the night, and then get anxious at not being able to get back to sleep, which in itself exacerbates any sleeplessness.

这种睡眠方式也许更自然，但是否更健康呢？专家提醒，由于相关研究数量有限，分段睡眠的风险和益处仍未被充分了解。尽管如此，一些人发现这种方式能帮助他们腾出时间进行创造性活动。心理学家格雷格·雅各布斯认为，在过去的几个世纪里，人们夜间清醒的那段时间，可能被用来调节压力。其他专家则提醒我们，很多人会在夜里醒来，并因无法再次入睡而感到焦虑，而这种焦虑本身反而会加重失眠。

Making use of the awake time to do something restful could help people improve their sleep. If you do want to try it, sleep researcher Mary Carskadon reminds us that we should stay away from bright lights to avoid disturbing our circadian rhythms. You also might want to check that it won't disturb your work and social life too much.

如果能善用夜间清醒的时间，去做一些让人放松的事情，或许有助于改善睡眠。如果你想尝试这种方式，睡眠研究员玛丽·卡斯卡登提醒，应当远离强光，以免干扰昼夜节律。同时，你也需要确认这种作息不会对你的工作和社交生活造成太大的影响。