關愛大腦，好好睡覺

I’m sure a lot of subway riders are skilled nappers， but this car seemed to be particularly talented. Going over the Brooklyn Bridge on a recent morning， just as the sun was coming up， a row of men in nearly identical black suits held on to the straps with their eyes closed. Their necks were bent at the slightest of angles， like a row of daisies in a breeze， and as the car clanged over the tracks and the sun pierced through the 1）grimy train windows， it finally 2）dawned on me that they were all sound asleep. Not even the bumps and the light could stop them from sneaking in 15 more minutes of shut-eye before work.

We take it for granted， but most people have to wake up for work （or school or other morning obligations） long before they want to. 3）Sleeping in is treated as a cherished luxury—it’s somehow become normal that people wake up still exhausted， and anything but is a notable exception.

But rising before the body wants to affects not only morale and energy， but brain function as well.

“The practice of going to sleep and waking up at‘unnatural’ times could be the most prevalent high-risk behavior in modern society，” writes Till Roenneberg， a professor of 4）chronobiology at the Institute of Medical Psychology at 5）Ludwig-Maximilians University in Munch.

In fact， according to Roenneberg’s groundbreaking study in Current Biology， about one-third of people living in first-world countries are required to wake up two hours before their 6）circadian clocks， or “natural waking times，” and 69 percent of people have to wake up one hour before their bodies would like them to.

Of course， different people require different amounts of sleep， and， although there’s no universal rule for how long we should all be sleeping， it’s becoming increasingly clear that working late and waking early can cause serious problems. It’s not just repeated sleep deprivation that 7）does people in， either. Just one restless night can seriously affect us in the morning.

Getting less than five hours of sleep a night makes people dumber and less able to concentrate， and it can make people more 8）susceptible to 1 memories， according to a new study published in the September issue of Psychological Science. Led by Steven J. Frenda of the University of California， Irvine， the study found that of the 193 people tested， participants who slept for less than five hours a night were significantly more likely to say they had seen a news video when they in fact never had. The sleep-deprived group was also more suggestible. While recounting a personal story， 38 percent of them incorporated 1 information the researchers had given them， whereas only 28 percent of those who had more than five hours of sleep accepted the researchers’1 information in their story retelling. Frenda and his researchers 9）postulate that not sleeping enough significantly disturbs our ability to encode information.

They also question the legitimacy of eyewitness testimonies in a court of law since， in this study， a good deal of people—especially those who didn’t get enough sleep—were susceptible to 1 memories. If someone goes on the stand after a sleepless night， it seems the chances are higher that he may misremember events.

The importance of sleep goes beyond courts and companies though. In the classroom， students who sleep more tend to be better at remembering what they’ve learned in the previous day than those who slept less， according to a 2001 study published in Science， and a 2014 study confirmed that more sleep leads to higher exam scores as well. Students who slept seven hours the night before an exam that tested them on economics， languages， and math， scored an average of 9 percent higher than students who only slept six hours the night before.

Getting less than five or six hours of sleep has also been connected to the inability to learn motor sequences. So before learning to play piano， first focus on getting proper sleep.

But there is the possibility of overriding the mind and body’s desire for sleep. By simply telling themselves they’ve slept well， studies show that people can temporarily trick their brains. Of course， continually getting too few hours of shut-eye will eventually cause problems， but telling yourself you got more sleep and that you feel refreshed （even if you don’t） leads to increased cognitive functioning in the morning， as evidenced by selfdupers who scored significantly higher on verbal fluency and 10）neural processing tests.

The sleeping subway riders were also on to something. Even after a terrible night’s sleep， a 10-minute nap can significantly increase short-term 11）alertness and improve problemsolving skills.

As we reached the Chambers Street subway station， the row of suited men and women seemed to instinctively know that they had arrived at their stop. In unison， they began to open their eyes and force themselves awake. Some gave themselves little slaps on their cheeks； others rubbed their eyes and temples. Then， like 12）marionettes on a string， their spines straightened， their gazes turned straight ahead， and they clutched their briefcases and stepped out the door， onto the quay， up the stairs， and out onto the street， already noisy and awake.

我肯定許多地鐵乘客都是打盹高手，但是這節車廂里的乘客似乎特別天賦異稟。在最近的一個早上，太陽才剛剛升起，在經過布魯克林大橋時，一排身穿幾近一模一樣的黑西裝的男士正閉著眼睛抓著地鐵上的拉環。他們的脖子微微彎曲，角度極小，像一排雛菊在微風中搖曳，而當車廂與軌道叮當作響，陽光透過臟兮兮的車窗照射進來時，我終于意識到他們都處于熟睡當中。就算是顛簸和陽光也無法阻止他們在上班前悄悄地閉目養神1 5分鐘以上。

雖然我們視之為理所當然，但是許多人都不得不早早起來工作（或者上學，或者做其他早務），盡管他們還不想起床。睡懶覺被視為珍貴的奢侈品—不知為何，人們拖著疲憊的身軀被迫起床已變成了家常便飯、極為稀松平常之事。

但是在身體愿意蘇醒前掙扎起床不僅會影響人的士氣和精力，還會影響大腦的運轉。

“在‘不正?！臅r間點睡覺和起床可能是現代人最普遍的不健康行為，”提爾·羅內伯格這樣寫道，他是慕尼黑大學醫學心理學院生物鐘學的一名教授。

事實上，根據羅內伯格在《當前生物學》上發表的具有突破性的研究報告顯示，在第一世界國家有三分之一的人的起床時間得比他們的生物鐘起床時間，或者說“自然醒時間”提前兩個小時，69%的人得提前一個小時。

當然，不同的人所需要的睡眠量并不一樣，然而，盡管并沒有普遍的規律表明我們必須得睡夠多長時間，但是越來越多的證據顯示，遲睡早起會引起嚴重的問題。……