????如果真是這樣的話，為什么這些藥物的使用者堅稱自己睡得更好了呢？蘭德爾的解釋是，安必恩和魯尼斯塔等藥物會導致“順逆行遺忘（anteretrograde amnesia），使大腦暫時很難形成新的短期記憶。”因此，他堅稱，即使整個晚上輾轉反側，當你早上醒來時也根本意識不到這一點（許多醫生認為，無知或許對我們有好處——這是寬慰話；我們不記得的失眠不會讓我們產生焦慮感）。

????蘭德爾在書中提到了許多與打瞌睡的歷史和進化生物學有關的事實，非常引人入勝。他運用口語化、易于閱讀的語言，詮釋了男人和女人睡眠方式存在的差異，以及夫婦分開睡為什么效果反而更好等問題。此外，他還聲稱，床墊無關乎睡眠質量，他援引的一項研究顯示，不管是在混凝土板上，還是在加熱的高科技床墊上，受試者都睡得一樣好。然而，就總體而言，蘭德爾沒有、也不打算為夜不能寐者提供太多具有操作性的建議。

????這本書提及的最可行的睡眠訣竅或許與體育博彩有關。我們的晝夜節律時常讓我們在大約早上9點到下午2點左右這段時間內保持警覺，“在這個時間點上我們需要開始考慮小睡一下，”蘭德爾寫道。下午6點左右時，我們的身體獲得另一輪能量注入，效果可持續至晚上10點鐘左右。“力量、柔韌性和反應時間會激增。”你或許會問，這跟“周一橄欖球之夜（Monday Night Football）”有什么關系呢？無論比賽地點是在什么地方，周一的橄欖球賽通常都在美國東部時間下午8點半開賽，因此對于西海岸球隊而言，比賽時間總是下午5點半——正好是他們的夜晚能量獲得提升的時候。而東海灣球隊“在首節比賽結束之前，其身體的巔峰狀態就已結束。”研究人員發現，在過去25年間，無論是否擁有主場優勢，西海岸球隊在大約63%的時間里都擊敗了東海岸球隊，平均多出了2次觸地得分，并且在70%的時間里贏得得分差。謝謝你，大衛?蘭德爾！

????《夢境》一書最強大、最揮之不去的效果就是一種失落感：我們曾經睡得如此之好，睡得如此動人，這種美好經歷再也不會有了！我們基本上已經放棄了打瞌睡的習慣，甚至在一些曾經把午睡奉為一項人權的國家也是如此（盡管廣泛的研究顯示，短短15分鐘的午睡就可以提高一個人的認知能力）。

????當蘭德爾揭示出另一個已經被我們舍棄的儀式（我們“夜間生活”一段既甜蜜又隱秘的間隔期）時，這種頭痛感就加劇了。喬叟的《坎特伯雷故事集》（Canterbury Tales）和其他早期文本都提到過“首次睡眠”和“二次睡眠”。歐洲人過去習慣從日落時分一覺睡到午夜之后，在那時他們通常會心滿意足地保持大約1小時的清醒，然后再繼續睡覺至太陽升起的時候（最近一項研究顯示，長時間撤回人造光也能夠產生同樣的間隔期）。在這段清醒的夜半時分，人們通常會“祈禱、閱讀、沉思或者做愛。”

????研究顯示，這個間隔期“或許是他們一生中最放松的時間段，”標志是身體產生出更多的

????催乳激素。這種激素有破除壓力的效果，它“正是人們在極度興奮后感到放松的原因所在。”一些非工業化社會依然在實踐著這種分割式睡眠，但在西方國家，這一神奇的時光似乎已無法挽回了。正如蘭德爾的著作所示，我們的睡眠時常是一段異常艱辛、最終以猛然覺醒結束的旅程。

????譯者：任文科

????If that's the case, why do users of these meds insist they sleep better? Randall's explanation is that drugs like Ambien and Lunesta cause "anteretrograde amnesia … making it temporarily harder for the brain to form new short-term memories.'' So even if you toss and turn all through the night, he maintains, you simply won't realize it when you wake up in the a.m. (Many doctors think that ignorance may do us some good, placebo-style; the insomnia we don't remember won't make us anxious.)

????Randall presents a pile of often-fascinating facts on the history and evolutionary biology of the nod. In colloquial, easy-reading prose, he explains how men and women sleep differently, and why couples would do better to sleep apart. He also argues that mattresses don't matter, citing a study in which subjects slept just as well on a concrete slab as on a heated, high-tech prototype mattress. In general, however, Randall doesn't -- and doesn't set out to -- offer much practical advice that the individual toss-and-turner can use.

????The most actionable tip in the book may be on sports betting. Our circadian rhythms keep us alert from around 9 a.m. until 2 p.m. or so, "which is when we start thinking about a nap,'' Randall writes. At round 6 p.m., the body gets another energy infusion that lasts until roughly 10 p.m. "Strength, flexibility and reaction times surge." What does all that have to do with Monday Night Football, you ask? MNF games kick off at or just after 8:30 p.m. EST, no matter where they're played, so it's always 5:30 p.m. for West coast teams -- just about time for their evening power boost. East coast teams "are past their natural performance peaks before the first quarter ends.'' Over 25 years researchers studied, West coast teams defeated Easterners 63% of the time, by an average of two touchdowns -- and beat the point spread 70% of the time, regardless of who was home or away. Thank you, David K. Randall!

????One of Dreamland's strongest and most lingering after-effects is a sense of loss, the notion that we once slept so much better -- even beautifully -- and never will again. We've largely abandoned the nap, even in countries where the siesta was once a human right. (This in spite of extensive research showing that as little as 15 minutes of napping improves cognitive abilities.)

????That ache increases when Randall reveals a different ritual we've forsaken, a sweet, secret interval in our "life after dark.'' Chaucer's Canterbury Tales and other early texts refer to "first sleep'' and "second sleep.'' It seems that Europeans used to sleep from sundown or thereabouts until after midnight, when they would regularly, contentedly stay awake for an hour or so, and then snooze until sunrise or morning. (A recent study that withdrew artificial light for an extended period produced these same intervals.) That awake-break was spent "praying, reading, contemplating … or having sex.''

????Research indicates this period was "probably the most relaxing block of time in their lives,'' marked by higher production of prolactin, a stress-busting hormone "responsible for the relaxed feeling after an orgasm.'' Some non-industrialized societies still practice split sleep, but here that magic hour seems irretrievable. As Randall's book shows, ours is all too often a troubled sleep, followed by rude awakenings.