年齡越大真的睡得越少嗎

老年人說自己睡眠不佳是常見的事。

There seem to be two main difficulties: falling asleep at the start of the night and then waking up too early in the morning – yet finding it impossible to get back to sleep.

這大概體現(xiàn)在兩個方面：一入夜就睡著了，早上很早起來——然后再想繼續(xù)睡似乎不可能。

In some cases, the discomfort caused by a medical condition exacerbates sleep difficulties, but many find that even without the disturbance of physical symptoms, sleep still eludes them for at least part of the night.

在一些情況下，醫(yī)學(xué)病癥加重睡眠困難，但很多人發(fā)現(xiàn)即使沒有受到軀體癥狀的干擾，睡眠至少在夜晚的某個時段遇到困擾他們。

In a new study from Russia, 130 people went to a laboratory one morning and then stayed there all day and overnight. Staff kept them awake for the entire time, regularly asking them to assess how sleepy they felt.

在俄羅斯的一項新研究里，130人于早上去實(shí)驗(yàn)室，在那里呆了整天整夜。工作人員讓他們一直保持清醒，并有規(guī)律地要求他們評估犯困的感覺。

These feelings of sleepiness vary throughout the day and night and in sleep deprivation experiments such as this, they are taken to reflect processes related to the body clock such as changes in body temperature at different times of day and the release of the hormone melatonin in the evening.

嗜睡的感覺在該睡眠剝奪實(shí)驗(yàn)的整個白天和晚上都有所不同，這些感覺被記錄下來，它反應(yīng)了人體生物鐘的運(yùn)動過程，比如在一天的不同時間內(nèi)體溫的變化和夜間褪黑激素的釋放。

The slow-wave activity in the volunteers’ brains was also measured several times during the day and night.

志愿者的大腦慢波活動同樣在白天和晚上多次被測量。

Then all this data was analysed in relation to a sleep diary the people had kept for the previous week, in order to see how the pattern of sleepiness and slow brainwaves varied according to propensity to be morning or evening types.

所有的數(shù)據(jù)與這些人在前一周的睡眠日記相比較進(jìn)行分析，以了解嗜睡模式和緩慢腦電波是如何在早上和晚上變化的。

They found that, once again, the older people felt sleepy at different times from the younger people and had different timings of slow-wave activity in the brain.

他們再次發(fā)現(xiàn)，老年人與年輕人在不同的時間犯困，并且大腦慢波活動的時段也不同。

The study’s author, Arcady Putilov, suggests that two mechanisms might be responsible for the decrease in sleep time.

該研究的作者Arcady Putilov認(rèn)為這兩個因素可能是睡眠時間減少的原因。

He believes that in middle age the processes underlying the oscillations of slow-wave sleep weaken, making it harder to stay asleep, and on top of that, in older age the stronger circadian rhythms weaken because changes in body temperature and the release of the hormone melatonin weaken.

他認(rèn)為中年人的慢波睡眠的振蕩的潛在過程變?nèi)酰@使得保持睡眠更加困難，加之，由于體溫變化和褪黑激素釋放變?nèi)?，年紀(jì)越大，生理節(jié)奏則越弱。