不少人都认为一次性睡够八小时是维持睡眠健康的关键，但这个习惯很可能是一个相对现代的产物。我们的许多祖先曾经每晚都有两段睡眠，并经常在两段睡眠之间起床活动。一些证据也指出，这种睡眠方式可能更加自然。本文浅谈人类睡眠习惯的演变。

词汇：sleep 睡眠

1 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?

2 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.

3 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.

4 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.

5 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.

测验与练习

一、将标题和段落配对。

Paragraph 1 _______
Paragraph 2 _______
Paragraph 3 _______
Paragraph 4 _______
Paragraph 5 _______

a. Lack of studies
b. Natural patterns
c. Fighting insomnia
d. Impact of electric light
e. Advice for biphasal sleeping
f. Recommended sleep habits

二、根据文章内容选出正确的选项。

1. Good sleep hygiene means avoiding coffee before bed.
a. True
b. False
c. Not given

2. Technological change has changed the way that people sleep.
a. True
b. False
c. Not given

3. What does 'they' refer to in the following sentence? 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.
a. modern sleep patterns
b. modern lifestyles
c. segmented sleep patterns

4. Studies have shown that bright light keeps people awake.
a. True
b. False
c. Not given

5. Doing something active during the time between sleeps can help people sleep better.
a. True
b. False
c. Not given

三、用方框中的单词完成对本文的总结。

1) _______ sleep patterns were common in past centuries. Without artificial light, people would often start to feel 2) _______ once the sun set. They would then 3) _______ themselves before midnight. Some people have found that copying this means that they can do something 4) _______ when they wake at night. This means that they don't spend time worrying about their 5) _______.

rouse
sleeplessness
drowsy
segmented
darkness
circadian rhythms
restful

（答案见词汇表后）

词汇表

sleep hygiene 睡眠卫生
rest 休息
sleep pattern 睡眠模式
sundown 日落
rouse 叫醒，唤醒
sunset 日落（时分）
sunrise 日出（时分）
segmented 分段的
biphasal 分为两个阶段的
circadian rhythms 昼夜节律，生物钟节律
drowsy 困倦的，昏昏欲睡的
darkness 黑暗
wake 醒来
anxious 焦虑的，紧张的
sleeplessness 失眠
restful 令人放松的，有利于休息的

答案

一、将标题和段落配对。

Paragraph 1 f) Recommended sleep habits
Paragraph 2 d) Impact of electric light
Paragraph 3 b) Natural patterns
Paragraph 4 a) Lack of studies
Paragraph 5 e) Advice for biphasal sleeping

二、根据文章内容选出正确的选项。

1. a. True. No phones or caffeine before bed, and make sure that we get a good eight hours' rest.

2. a. True. Artificial light in our houses and streets means that we no longer have to go to bed at sundown.

3. c. 'They' refers back to segmented sleep patterns mentioned in the previous sentence.

4. c. Not given. The article doesn't mention any studies into bright light keeping people awake

5. b. False. Making use of the awake time to do something restful could help people improve their sleep.

三、用方框中的单词完成对本文的总结。

Segmented sleep patterns were common in past centuries. Without artificial light, people would often start to feel drowsy once the sun set. They would then rouse themselves before midnight. Some people have found that copying this means that they can do something restful when they wake at night. This means that they don't spend time worrying about their sleeplessness.