Why Hammocks Make Sleep Easier, Deeper

 Why Hammocks Make Sleep Easier, Deeper

Napping in a hammock is one of the more delightful¹ tasks of summer, and Swiss researchers say they now know why.

The gentle rocking motion makes people fall asleep faster, and they sleep deeper. Those changes in brain activity may inspire new ways to help insomniacs, the researchers say.

Neuroscientists at the University of Geneva rigged up a bed so it would sway gently from side to side every four seconds, considerably³ slower than the pendulum⁴ on a cuckoo clock. "This rocking is very gentle, very smooth, oscillating every four seconds," Sophie Schwartz, a professor of neurology who led the study, told Shots. "It's not like rocking like you would see some mothers rocking their babies, it's more gentle."

A dozen adult research subjects napped on the bed for 45 minutes while scalp electrodes recorded brain activity. During one nap the bed swayed; for another, it was stationary⁵.

The scientists weren't too surprised to find that people fell asleep faster when the bed rocked. But they were surprised at the big difference that rocking made in brain activity.

Rocking increased the length of N2 sleep, a form of non-REM sleep that takes up about half of a good night's rest. It also increased slow oscillations and "sleep spindles." Sleep spindles are brief bursts of brain activity, which look like sudden up-and-down scribbles⁶ on an electroencephalogram.

"We were basically trying to find a scientific demonstration⁷ of this notion of rocking to sleep," Michel Muehlethaler, a professor of neuroscience who conducted the research with Schwartz, tells Shots. The fact that the brain waves changed so much, he says, was "totally unexpected." The results were published in the journal Current Biology.

Sleep spindles are associated with tranquil⁸ sleep in noisy environments and may be a sign that the brain is trying to calm sleepers⁹ stuck in them. Spindles also have been linked with the ability to remember new information. And that is associated with the brain's ability to rewire itself, known as brain plasticity.

That ability is important in recovery from stroke, and the researchers say that rocking while sleeping should be tested on people with strokes or other brain injuries. Rocking is "changing things in your brain," Schwartz says.

The Swiss scientists are eager to try the rocking bed on night-time sleepers, to see if it might help with insomnia² and other common sleep disorders¹⁰. But Shots readers may not want to wait for those results, and instead head directly to the back yard and their own time-tested research tool, the hammock.

1 delightful   

adj.令人高兴的，使人快乐的

参考例句：

• We had a delightful time by the seashore last Sunday.上星期天我们在海滨玩得真痛快。
• Peter played a delightful melody on his flute.彼得用笛子吹奏了一支欢快的曲子。

2 insomnia   

n.失眠，失眠症

参考例句：

• Worries and tenseness can lead to insomnia.忧虑和紧张会导致失眠。
• He is suffering from insomnia.他患失眠症。

3 considerably   

adv.极大地；相当大地；在很大程度上

参考例句：

• The economic situation has changed considerably.经济形势已发生了相当大的变化。
• The gap has narrowed considerably.分歧大大缩小了。

4 pendulum   

n.摆，钟摆

参考例句：

• The pendulum swung slowly to and fro.钟摆在慢慢地来回摆动。
• He accidentally found that the desk clock did not swing its pendulum.他无意中发现座钟不摇摆了。

5 stationary   

adj.固定的，静止不动的

参考例句：

• A stationary object is easy to be aimed at.一个静止不动的物体是容易瞄准的。
• Wait until the bus is stationary before you get off.你要等公共汽车停稳了再下车。

6 scribbles   

n.潦草的书写( scribble的名词复数 )；乱画；草草地写；匆匆记下v.潦草的书写( scribble的第三人称单数 )；乱画；草草地写；匆匆记下

参考例句：

• The scribbles on the wall must be the work of those children. 墙壁上的涂鸦准是那几个孩子画的。 来自辞典例句
• There are scribbles on the wall. 墙上有胡乱涂写的字迹。 来自辞典例句

7 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。

8 tranquil   

adj. 安静的, 宁静的, 稳定的, 不变的

参考例句：

• The boy disturbed the tranquil surface of the pond with a stick. 那男孩用棍子打破了平静的池面。
• The tranquil beauty of the village scenery is unique. 这乡村景色的宁静是绝无仅有的。

9 sleepers   

n.卧铺（通常以复数形式出现）；卧车( sleeper的名词复数 )；轨枕；睡觉（呈某种状态）的人；小耳环

参考例句：

• He trod quietly so as not to disturb the sleepers. 他轻移脚步，以免吵醒睡着的人。 来自辞典例句
• The nurse was out, and we two sleepers were alone. 保姆出去了，只剩下我们两个瞌睡虫。 来自辞典例句

10 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》