Screen Time Can Mess with the Body

石斯琳

Reading on an iPad in the evening can make it hard for the body to fall asleep. For a good nights sleep， here is some expert advice： Turn off， turn in and drop off.

晚上睡覺前看蘋果平板電腦會更加難以入睡。為了擁有一個高質量的睡眠，這里提供一些專業意見：關掉蘋果平板電腦，放進抽屜，舒服入睡。

Anyone who does the opposite—say， turning on an iPad or other similar electronic reader in bed—may have a harder time both dropping off to sleep and shaking that groggy1 feeling the next morning. Thats the conclusion of a new study.

有的人所做的恰恰相反，例如在床上用著蘋果平板電腦或者其他電子閱讀設備。新研究結論表明，這些（夜晚入睡前還用電子設備的）人可能更加難以入睡，或者隔天整一個早上昏昏沉沉的感覺都會揮之不去。

Sleep experts at Brigham and Womens Hospital in Boston found that the light from a tablet2 computer upsets the bodys internal clock. They reported their findings in the Proceedings of the National Academy of Sciences. And that can create real health and safety risks， the researchers say. Reading a printed book did not have the same effect. An internal “clock” helps regulate3 when we eat， sleep and wake. Exposure to the light of day and darkness of night keeps its timing set to a roughly 24-hour cycle.

來自波士頓布里格姆女子醫院的睡眠專家們發現平板電腦發射出的光線會擾亂人體內的生物鐘。專家們在美國《國家科學院學報》上發表了他們的研究報告。研究結果顯示，這種擾亂會造成嚴重的健康安全問題。然而睡前閱讀紙質書籍并不會造成危害。當我們進食、入睡和醒來的時候，體內的生物鐘會對我們的身體進行調節。白天的光線和夜間的黑暗讓體內的生物鐘自動形成大致24小時的循環模式。

For instance， starting about two hours before bedtime， our brains start to produce a hormone called melatonin4. It signals5 our internal clock that darkness has fallen. It also prepares the body for sleep. Scientists long have known that light at night can disrupt6 that internal clock. And it does so by suppressing7 melatonin.

例如，在入睡前的兩個小時，我們的大腦就會開始自動分泌一種叫做褪黑激素的荷爾蒙。這種激素向我們體內的生物鐘發出黑夜降臨的信號，也為身體入睡做好準備?？茖W家很早就得出了夜晚的人照光線會擾亂人體內生物鐘，并抑制褪黑激素分泌的結論。

Electronic devices with lit screens are now hugely popular. They have added another source of artificial light at night. The new study looked specifically8 at the iPad. For their new study， the researchers recruited six men and six women， all in their mid 20s. Over two weeks， each spent four hours reading each evening before a 10 p.m. bedtime. The volunteers read on an iPad for five nights in a row. On another five consecutive9 evenings they read a printed book. The researchers noted how long it took the volunteers to fall asleep， how long they spent asleep and how long they remained in each stage of sleep. The experts also took blood samples to measure melatonin levels. People took nearly 10 minutes longer to fall asleep， on average， after reading on the iPads. There was no difference in hours spent sleeping after reading from either the iPad or a printed book. But how volunteers felt the next day did differ.

帶有照明屏幕的電子設備現在是炙手可熱的產品。它們為夜晚人造光增添了另一種新形式。新研究把關注重點放在了蘋果平板電腦上。在新研究中，研究者招募了六男六女共12個志愿者，年齡均在25歲左右。在長達兩個星期的研究過程中，每個志愿者在每天晚上10點（睡覺的時間點）之前花四個小時閱讀。這十二個志愿者連續五個晚上用蘋果平板電腦閱讀，另外五個晚上閱讀紙質書籍。研究者記錄下研究對象入睡需花費的時間，睡眠時長，以及每個階段的睡眠持續時間。專家還采集了血樣以測量褪黑素值。（結果顯示）那些睡前用蘋果平板電腦的人比不用的人平均需多花十分鐘才能入睡。然而不管是用蘋果平板電腦閱讀還是看紙質書籍，睡眠時長都沒有差別。差別在于志愿者隔天的精神狀況。

“Our most surprising10 finding was that individuals using the e-reader would be more tired and take longer to become alert the next morning，” says sleep researcher Anne-Marie Chang.

睡眠研究專家安娜-瑪麗·張表示：“最出人意料的發現是，用電子設備閱讀者第二天早上會更加疲憊，需要花更多的時間清醒?！?/p>

Regularly getting too little sleep can pose important health risks. For instance， studies have shown that it can up the risk of everything from obesity， diabetes11 and depression to car accidents.

經常性的睡眠不足會造成嚴重的健康問題。例如，研究表明睡眠不足可能引發諸如肥胖、糖尿病、抑郁甚至車禍等問題。

Notes：

1. groggy adj. 頭暈的；昏昏沉沉的

2. tablet n. 平板電腦

3. regulate vt. 調整

4. melatonin n. 褪黑激素

5. signal v. （發信號）通知、表示

6. disrupt vt. 破壞；使瓦解；使分裂

7. suppress vt. 鎮壓；壓制

8. specifically adv. 特別地；明確地；具體地

9. consecutive adj. 連續的；連貫的

10. surprising adj. 令人驚訝的，出人意料的

11. diabetes n. 糖尿病；多尿癥