睡前看手機或平板？快戒掉這個壞習慣！
理察·格雷（Richard Gray）
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你昨天晚上睡覺前乾的最後一件事情是什麼？你可能在一款電子設備（手機或平板電腦）上讀郵件、看網頁、刷朋友圈。
你這種情況絕非個例。美國國家睡眠基金會（National Sleep Foundation）的一項研究估計，58%的美國成年人在床上使用平板電腦或筆記本電腦等電子產品。其他國家的研究也表明，這種現象在年輕成年人中更加普遍。
但睡前使用電子設備會破壞你的睡眠：不僅會讓你遲遲不能入睡，還會導致你夜間頻繁醒來。更多的研究表明，夜裡使用科技產品會對人們的抗壓能力、自尊心和整體的心理健康產生不利影響。如果得不到充分的睡眠，你的工作效率就會降低，長期的健康也會受到影響，但似乎很少有人能夠抗拒這種誘惑。那麼，究竟為什麼這樣呢？
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發一條簡訊，在Facebook上發一篇帖子，或者查看一下電子郵件，意味著你需要等待回復，這就會加快情緒神經系統的運轉速度（圖片來源：Alamy）
睡眠、擾亂
與讀書和看電視不同，現代化的電子設備都採用互動模式，而不是被動接收信息。它們帶著連接外部世界的能力入侵了我們的臥室，那裡歷來都是我們放鬆身心、忘記忙碌的私密場所。
“這些設備都會引發睡眠拖延。”加州大學伯克利分校神經科學和心理學教授馬修·沃克爾（Matthew Walker）說。
專家表示，我們入睡前需要30分鐘到1小時的準備時間，好讓思維從一天的緊張中放鬆下來。看本書、喝杯熱飲或者做一些重複性任務（例如屬羊）都很有幫助。
但沃克爾表示，當我們拿起手機，其實就是在放棄大腦所需的準備過程，因為這樣會把白天及其附帶的所有緊張和焦慮都延伸到晚上。
“如果手機沒電或者出現故障，我們或許會感覺很困，很容易入睡。”他說，”但當我們拿起這些設備，就會因此推遲睡眠。當人們上床之後，往往還會有人在Facebook上聯繫他們，或者給他們發送郵件。不知不覺間，二、三十分鐘就過去了。”
“發一條簡訊，在Facebook上發一篇帖子，或者查看一下電子郵件，意味著你需要等待回復，這就會加快情緒神經系統的運轉速度。之後，當你把它放在床邊，只要手機仍然開著，就會不停地出現各種提示音，在夜間把你吵醒。”
看書或看電視熬夜，與使用智慧型手機、平板電腦和筆記本熬夜，似乎存在顯而易見的差異。研究人員表示，我們與電子設備的互動方式導致原本應該睡覺的時間遭到大量蠶食。
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在回顧了20項關於兒童睡眠狀態的研究後發現，在房間裡使用移動設備的兒童睡眠深度較差（圖片來源：Alamy）
例如，很多電子設備發出的藍光會改變褪黑激素的釋放（這種激素有助於調節睡眠），而且會導致體內生物鐘的錯位。
愛不釋手
倫敦大學國王學院精神病學院生物統計學家本·卡特（Ben Carter）過去幾年一直在研究科技對睡眠的影響。他發現，在臥室里使用電子設備與睡眠不良之間存在很強的相關性。
卡特表示，我們允許自己夢遊”進入這樣一種環境：我們跟科技同床共枕，讓它控制我們。”他說，”這無疑會對我們的睡眠質量產生長期影響。”
究竟為什麼會產生這樣的危害？卡特將我們使用這種設備的方式比作吸菸。
“如果這是你晚上入睡前的最後一件事情和早晨起來後的第一件事情，那你可能就上癮了。”他說。卡特表示，全天候獲取信息並與他人互動的能力，已經全面滲透到我們渴望知識、喜歡社交的大腦中，甚至還會影響那些應該更加了解此事的人。
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長期使用手機會讓人成癮，這一點跟吸菸很像（圖片來源：Getty Images）
“我最近跟一個上癮的教授聊過，他說他夜裡會醒來用手機查看美國的報紙。”卡特說，”我也知道不應該睡覺前看手機，我不想這樣，但我很難抗拒。
睡眠專家認為，與戒菸一樣，我們必須學會在晚上戒除電子產品，這樣才能安心地把它們丟在另一個房間。
美國國家睡眠基金會發現，五分之一的受訪者會在夜間被設備驚醒，其中半數隨後會拿起手機來使用。
卡特對20項研究進行了評估，希望了解科技對兒童睡眠狀況的影響。結果發現，即便兒童在上床前不使用手機或其他設備，但只要在臥室里放有這些設備，其深度睡眠狀況仍然趕不上直接把設備放在另一個房間的兒童。
“只要把設備放在自己的臥室，就會影響睡眠。”卡特說，”兒童仍會在認知上與設備互動。”
“只要把能夠引發焦慮感的東西放在臥室里，就會改變你的睡眠質量。”沃克爾說。擔心第二天的事情（例如進行一場重要的工作演講）不僅會導致人們失眠，還會在他們入睡時後縮短深睡時間。
睡眠不足和成癮
美國疾病控制和預防中心表示，35%的美國成年人睡眠不足，高於10年前的29%。具體來看，美國疾控中心現在估計，有7,000萬美國成年人每晚睡眠不足6小時。這會引發流行病，導致人們難以在工作時集中精力，甚至損傷記憶。睡眠不足還會增加車禍和工業事故的風險。
科學研究已經將進一步的睡眠不足與各種健康問題聯繫起來，從心臟病和肥胖到糖尿病和抑鬱症。
“這恐怕是當今時代尚未解決的公共健康問題中最大的一個。”科林·艾斯派（Colin Espie）說，”對於很多幫助我們保持健康和幸福的生理機能來說，睡眠都至關重要。”
但令人意外的是，沃克爾表示，想要調節睡眠，或許仍然要從科技中尋找答案。市面上已經有很多電子產品號稱可以監控和輔助睡眠。沃克爾希望使用機器學習技術製作新的方法，以便在人們睡眠不好的時候進行干預。
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華盛頓州立大學斯波坎校區睡眠和績效研究中心採用多導睡眠圖記錄系統來衡量睡眠質量（圖片來源：Getty Images）
“應該可以為每個人開具精確的睡眠處方，以此改善他們的睡眠。”他說，”可以看看你第二天的日程表，然後這樣想：因為你第二天早晨要早起，所以現在就應該準備上床睡覺，這樣才能獲得充分的睡眠。”
類似地，他認為還可以藉助算法在幾周的時間裡逐步調整我們的就寢時間，從而幫助我們為出國旅行和時差反應做好準備。
“毫無疑問，電子設備一直在干擾我們的睡眠。”沃克爾說，”但我認為，科技也可以拯救我們，幫助我們糾正睡眠狀態。”
Are You A Sleep Procrastinator?
By Richard Grayn
12 September 2017
What was the last thing you did before drifting off last night? You were probably on a device: reading emails, surfing the web or checking social media.
You』re not alone. A study by the National Sleep Foundation estimates 48% of American adults use gadgets such as tablets or laptops in bed and studies in other countriesshow this is even more prevalent among younger adults.
But snuggling up with electronic devices is ruining your sleep: keeping you up later and waking you more frequently during the night. More research has shown that night time use of technology can have a detrimental effect on ability to cope with stress, self-esteem and general mental health. Without sufficient sleep, you』re less productive at work and long term health can suffer but few seem able to resist. So why do we do it?
Sending a text message, posting on Facebook or checking your email means you are waiting for a response, which revs up your emotional nervous system (Credit: Alamy)
Sleep, interrupted
Unlike reading and TV, modern gadgets are interactive rather than passive. Their connectivity to the outside world intrudes into the bedroom, a place that has historically been somewhere private to unwind and forget about a hectic day.
「These devices are causing sleep procrastination,」 says Matthew Walker, a professor of neuroscience and psychology at the University of California, Berkeley.
Experts say we need between 30 minutes and an hour of preparation before going to sleep to give our minds a chance to unwind from the stresses of the day. Things like reading a book, having a hot drink or doing a repetitive task like counting sheep all help.
When we pick up our phones, we are undoing that preparation our brains need by extending the day into the night-time hours
But, says Walker, when we pick up our phones, we are undoing that preparation our brains need by extending the day – together with all the stress and worry from it – into our night-time hours.
「We might feel perfectly sleepy and could drop off easily if the power went out and our phones didn』t work,」 he says. 「But when we pick up these devices it allows us to put off sleep. Often people will get into bed, someone will ping them on Facebook or send an email, and before they know it 20 to 30 minutes has gone.」
「Sending a text message, posting something on Facebook or checking your email means you are waiting for a response and revs up your emotional nervous system. Then once you put it down by your bedside, if you leave the phone on, there are all the pings, dings and other sounds that can wake you up during the night.」
It appears there is a marked difference between staying up late with a good book or watching television in bed and using smartphones, tablets and laptops. The way we interact with electronic devices allows them to eat into far more of the time we should be asleep, according to researchers.
A review of 20 studies on children’s sleep patterns found that children with mobile devices in their rooms slept less deeply (Credit: Alamy)
For example, the blue light given off by many electronic screens can alter the release of a hormone called melatonin, which helps regulate sleep, and can throw the body’s internal biological clock out of sync.
Can’t put it down
Ben Carter, a biostatistician at the Institute of Psychiatry at King’s College London, has spent the past few years studying the impact of technology on sleep and has uncovered strong associations between the use of portable electronic devices in the bedroom and poor sleep.
Carter says we have allowed ourselves to sleepwalk 「into a situation where we are in bed with our technology and it is controlling us,」 he says. 「There is no question that can have long-term impacts on the quality of our sleep.」
So, given the harm this can do, what’s going on? Carter likens the device behaviour to smoking.
「If it is something you do last thing at night and first thing in the morning, then you are probably addicted,」 he says. According to Carter, being able to access information and engage with others around the clock is so pervasive to our knowledge-hungry, social brains that it can even affect those who should know better.
Much like smoking, chronic phone use can be an addiction (Credit: Getty Images)
「I talked recently with a professor of addiction who told me he wakes up in the night to check the American newspapers on his phone,」 says Carter. 「I also know I shouldn』t check my phone before bed, I don’t want to do it, but it is actually very hard to detox.」
Sleep experts believe that, like quitting cigarettes, we must learn to wean ourselves off our gadgets at night so we feel comfortable leaving them in another room.
Just the presence of the device in their bedrooms was affecting their sleep
The National Sleep Foundation in the US found a fifth of people it surveyed were woken up by their devices in the night and half of those then picked them up to use them.
Carter conducted a review of 20 studies into the impact of technology on children’s sleep patterns, finding even those who did not use phones or other devices before bed but had them in their bedrooms, slept less deeply than those who left their devices in another room.
「Just the presence of the device in their bedrooms was affecting their sleep,」 says Carter. 「These children were still cognitively engaged with their devices.」
「Just having an object that creates a sense of anxiety in your bedroom will actually change the quality of your sleep,」 says Walker. Worrying about something happening the next day, such as giving an important presentation at work, has been shown to not only keep people awake at night but also decrease the amount of deep sleep they get when they do drift off.
Deficiency and addiction
The Centers for Disease Control and Prevention in the US says that 35% of American adults are not sleeping enough, an increase from 29% ten years ago. To put this in perspective, the CDC now estimates 70 million US adults are sleeping less than six hours a night. This, it says, is leading to an epidemic of people struggling to concentrate or remember things at work. Insufficient sleep is also implicated in an increased risk of car crashes and industrial accidents.
Further sleep deficiency has been linked to a wide range of health problems, from heart disease and obesity to diabetes and depression.
It is perhaps the biggest unaddressed public health issue of our time – Colin Espie
「It is perhaps the biggest unaddressed public health issue of our time,」 says Colin Espie, professor of sleep medicine at the University of Oxford. 「Sleep is essential for a wide range of functions that serve our health and well being.」
Yet surprisingly, Walker says technology itself may hold the answer to regulate our night time slumbers. There are already many gadgets on the market that claim to monitor and aid sleep. And Walker hopes to use machine-learning technology to produce new ways of intervening if someone is not sleeping properly.
Washington State University Spokane’s Sleep and Performance Research Center employs polysomnographic recording systems to measure sleep quality (Credit: Getty Images)
「It should be possible to produce a precise sleep prescription for each person to improve their sleep,」 he says. 「It could look at your calendar for the next day and suggest that because you have an early morning call in the morning, it might be worth getting ready for bed now so you can get enough sleep.」
Similarly, he suggests that algorithms could also gradually adjust our bedtime over several weeks to help us prepare for trips abroad and combat jet lag.
「There is no doubt that sleep has been desperately disrupted by our gadgets,」 says Walker. 「But I also think technology could be our salvation by helping to correct our sleep too.」