半夜驚醒突然發現自己動彈不得、說不出話，你有過這種「鬼壓床」的經歷嗎？「鬼壓床」往往還伴隨著各種解釋不清的怪異現象和感覺，甚至有人自稱看到了鬼。那麼，真相到底是什麼呢？
Photo by Stefano Pollio on Unsplash
You jerk awake in the middle of the night in confusion. Is there a figure standing in the corner of the room? Your brain begs your limbs to move, but nothing happens. The anxiety increases. Your eyes scan the room. Just as you’re about to hit peak panic, you sit up and the figure disappears.
半夜裡你突然莫名其妙地驚醒。房間的角落似乎有個人影。你想要動動四肢，但卻動彈不得。你越來越焦慮。你的眼睛掃視著房間。就在你的恐慌情緒即將達到頂峰時，你坐起來了，那個人影也消失了。
You』ve just experienced sleep paralysis, one of many 「parasomnias,」 which is the name experts give to all sorts of weird things that occur during sleep.
你剛剛經歷了睡眠癱瘓，它是眾多睡眠異常的一種。專家用睡眠異常來指代睡眠時發生的各種怪異事情。
Sleep paralysis happens when the brain incapacitates the body to prevent it from acting out the vivid dreams occurring during REM (or, rapid eye movement) sleep. It often comes with a feeling of immobility, and a sense of choking.
大腦為了阻止身體對異相睡眠（或快速眼動睡眠）期的生動夢境做出回應而使身體失去活動能力時，就會發生睡眠癱瘓，常常伴隨著一種無法行動的感覺和一種窒息感。
incapacitate[nkpstet]: vt. 使無能力；使不能；使不適於
什麼是睡眠癱瘓呢？
The good news is, it’s absolutely normal. Even if it’s terrifying.
好消息是，睡眠癱瘓雖然很恐怖，但絕對是正常現象。
But when sleep paralysis happens outside of deep sleep — when a person is just dozing off or waking up — it can be 「disruptive of the architecture of sleep,」 said Baland Jalal, a researcher who investigates the phenomenon. That could lead to more sleep paralysis. People with poor sleeping habits experience the phenomenon more frequently.
但是，研究這一現象的科研人員巴拉德·賈拉爾說，當睡眠癱瘓發生在深度睡眠之外——例如當一個人只是打瞌睡或快要醒來時——它可能會「破壞睡眠結構」。這可能會引發更多次的睡眠癱瘓。睡眠習慣差的人則會更頻繁地經歷這種現象。
While the mechanisms behind sleep paralysis remain murky, Jalal said stress and worry play a part. Recent research indicates that people with anxiety and PTSD report experiencing sleep paralysis more frequently.
賈拉爾說，雖然對睡眠癱瘓背後的機制依然沒有頭緒，但壓力和擔憂是導致睡眠癱瘓的原因之一。最近的研究表明，患有焦慮症和創傷後應激障礙的人會更頻繁地出現睡眠癱瘓。
「People who are anxious have much more emotional sleep. [They] are more likely to wake up during REM,」 said Jalal. 「If you have sleep paralysis, you probably also have anxiety.」
「焦慮的人在睡覺時受到更多情緒影響，他們更有可能在異相睡眠期間醒來，」賈拉爾說，「如果你有睡眠癱瘓的情況，那麼你也很可能感到焦慮。」
The anxiety feeds into the sleep paralysis, said Jalal. People fret about experiencing the panicky feelings of sleep paralysis, which makes it more likely to occur again.
賈拉爾說，焦慮會加劇睡眠癱瘓情況的發生。人們擔心會經歷睡眠癱瘓的恐慌感，這反而會使它更有可能再次發生。
While about 6 percent of the population will experience sleep paralysis at one point in their lives, it occurs in about 30 to 50 percent of people with narcolepsy, a sleep disorder that includes excessive daytime sleepiness, cataplexy, sleep paralysis, and hallucinations, said Dr. Nathaniel Watson, president of the American Academy of Sleep Medicine and co-director of the University of Washington Medical Sleep Center.
美國睡眠醫學研究院院長、華盛頓大學醫學睡眠中心聯合主任納撒尼爾·沃森博士說，雖然大約6%的人一生中會在某個時候經歷睡眠癱瘓，但大約30%到50%的嗜睡症患者中會出現睡眠癱瘓。嗜睡症的症狀包括白天過度睏倦、昏睡、睡眠癱瘓和出現幻覺。
narcolepsy[nɑrkolepsi]: n. 嗜睡症；發作性睡病
Students are more likely to experience sleep paralysis with as many as 28.3 percent of students reporting it.
報告顯示，學生更有可能出現睡眠癱瘓，比例高達28.3%。
Some people report the feeling that someone or something is trying to strangle or choke them or will see someone coming into their room and not able to move or scream, experts say. It can also happen when the person is awake, lasting from a few seconds to a minute or two. It's associated with hypnagogic hallucinations, which occur as a person is falling asleep.
專家稱，有些人報告說，睡眠癱瘓的感覺就像有人或者有東西在試圖把他們勒死或掐死，又或者是看到有人進到了房間裡，但他們卻無法移動或者叫喊。睡眠癱瘓也有可能發生在人醒著的時候，過程會持續幾秒到一兩分鐘。它與催眠幻覺有關，通常發生在人睡著的時候。
For most people, 「it is not indicative of any kind of disease,」 said Watson. While the experience feels frightening, the episodes last only a few seconds or minutes at most.
沃森博士說，對於大部分人來說，「睡眠癱瘓並不意味著任何疾病」。儘管這種經歷很恐怖，但是它每次只會持續幾秒，最多幾分鐘。
Most people slip out of it as quickly as they fell into it. A light touch from a partner can be enough to stop it, he said.他說，大部分人一進入睡眠癱瘓就能夠抽身而出。伴侶的輕輕觸碰就可以阻止睡眠癱瘓的持續。
鬼魂是真實存在的嗎？亦或是一種睡眠幻象？
While not everyone who has sleep paralysis experiences hallucinations, seeing a person or a ghost in the room is the most common vision, said Jalal.
賈拉爾說，並不是每個人都在睡眠癱瘓時出現幻象，最常見的幻象是看到房間內有人或有鬼。
Hallucinations vary by culture — the Chinese call it 「guiya」 or ghost pressure because they believe a ghost sits on people’s chests. In Newfoundland, it is the 「old hag」 because people see a witch and in Egypt people see Jinn (what Westerns call genies), which are known to hunt and sometimes kills their victims.
這種幻覺因文化而異——中國人稱之為「鬼壓床」，因為他們相信鬼怪會坐在人們的胸膛上。在紐芬蘭，人們稱之為「老巫婆」，因為人們出現的幻覺裡有一個巫婆。在埃及，人們看到的是精靈，精靈以狩獵聞名，有時會殺死他們的獵物。
These ghostly "waking dreams」 can involve serpents, spiders, intruders and even ghosts. They're often associated with feelings of dread.
這些幽靈般的「醒夢」內容可能涉及蛇、蜘蛛、入侵者甚至鬼魂。它們常常與恐懼感聯繫在一起。
Some experts have suggested that alien abductions are really just intense bouts of sleep paralysis.
一些專家指出，所謂的外星人劫持其實只是睡眠癱瘓的劇烈發作。
「When you live in a culture where you are afraid of it, you are much more likely to be anxious [about sleep paralysis] and experience it,」 Jalal said.
賈拉爾說：「當你身處在自己所懼怕的文化氛圍中，你就更有可能經歷睡眠癱瘓，並對其感到焦慮。」
Sometimes an environmental reason is the cause of the spectral vision.
有時，環境因素也會引發鬼怪的幻覺。
In 2005, the Journal of Emergency Medicine reported about a 23-year-old woman who was found delirious and hyperventilating after seeing a "ghost".
2005年，《急診醫學雜誌》報導了一名23歲的女人，她在看到「鬼魂」後出現精神錯亂和呼吸急促的症狀。
「On arrival in the ED (about 30 minutes later), the patient was still hyperventilating but was able to talk. She denied taking illicit drugs or alcohol but recalled seeing a ghost while taking bath,」 the researchers wrote.
研究者寫道：「到達急診室時（大約30分鐘後），患者仍然呼吸急促，但她能夠講話了。她否認服用違禁藥物或酒精，但她回憶說洗澡時看到了鬼。」
It was later determined that her new gas water heater had been improperly installed and her house was filled with carbon monoxide. After oxygen therapy, she made a full recovery.
後來確定了是她的新燃氣熱水器安裝不當，導致她的房子裡充滿了一氧化碳，她才會產生這種幻覺。經過氧氣治療後，她就完全康復了。
英文來源：CNN
翻譯：實習生李行
編審：丹妮
來源：中國日報網