一個永不睡覺的身體單元

According to the National Sleep Foundation, almost every part of the body experiences significant changes during sleep. When we fall asleep, sleep signals are sent throughout the body as thousands of neurons in the brain shift from the waking to sleeping state. Getting restorative sleep reinforces the cardiovascular and immune systems, helps regulate metabolism, consolidates memory, and allows the body to recover in general. Things like our breathing, muscle tone, heart rate, and hormone levels change considerably when sleeping.

根據(jù)美國國家睡眠基金會的報道，幾乎身體的每一部分在睡眠過程中都經歷了顯著的變化。當我們進入睡眠狀態(tài)時，睡眠信號被發(fā)送到全身，大腦中成千上萬的神經元從清醒狀態(tài)轉移到睡眠狀態(tài)。獲得恢復性睡眠可以增強心血管和免疫系統(tǒng)，幫助調節(jié)新陳代謝，鞏固記憶，并使身體總體恢復。睡眠時，我們的呼吸、肌肉張力、心率和激素水平都會發(fā)生顯著變化。

But according to a study in Nature Human Behavior, sleeping is not an isolated activity. Slumberers go into "standby mode," where they can continue tracking relevant signals, maintaining the ability to "rapidly awake when necessary." It's how a new parent can wake instantly to the sound of their crying infant but ignore the din of traffic outside their window. Or how you can wake up to the sound of someone calling your name, but tune out other conversation.

但根據(jù)《自然人類行為》的一項研究，睡眠并不是一項孤立的活動。睡眠者進入“待機模式”，他們可以繼續(xù)跟蹤相關信號，保持“必要時快速醒來”的能力。這就是為什么新手爸媽能夠在聽到嬰兒哭鬧聲時立即醒來，而忽略窗外的交通噪音。或者你可以在聽到有人叫你的名字時醒來，而聽不到其他的談話。

Researchers at Vanderbilt University studied the brainwaves of preschool-aged children to look for memory traces for sounds heard during nap time (via Newswise). The researchers tested children individually using a portable electroencephalogram (EEG) machine in a silent room at a university preschool. Once the children were asleep, three "nonsense words" were played to each child for a short span of time. Then, once the children were awake, they were again hooked up to the EEG machine and played the same words, mixed in with other words they had not heard previously. The children showed positive signs for recognizing these test words, indicating that they continued to process auditory information even when sleeping.

范德比爾特大學的研究人員研究了學齡前兒童的腦波，以尋找在午睡時聽到的聲音的記憶痕跡。研究人員在一所大學幼兒園的一間安靜的房間里，使用便攜式腦電圖儀對兒童進行了單獨測試。一旦孩子們睡著了，就開始播放三個“無意義的單詞”，時間很短。然后，一旦孩子們醒來，他們再次被連接到腦電圖機，播放相同的單詞，并混入其他他們之前沒有聽到的單詞。這些孩子在識別這些測試詞時表現(xiàn)出積極的跡象，這表明他們即使在睡覺時也在繼續(xù)處理聽覺信息。

Thomas Andrillon, a research fellow at Monash University in Australia who worked on the Nature Human Behavior study, confirmed that people are more likely to wake up to relevant sounds. "It seems therefore that the sleeping brain remains somewhat vigilant," he told Vice. So even though it might seem like our ears turn off while sleeping, science tells us they're always on alert. Next time you think your sleeping partner or child in the room can't register what you're saying, think again.

澳大利亞莫納什大學(Monash University)研究人員托馬斯·安德里隆(Thomas Andrillon)參與了《自然與人類行為》(Nature Human Behavior)的研究，他證實，人們更有可能在相關聲音中醒來。“因此，睡眠中的大腦似乎仍保持著一定程度的警覺。”所以，盡管看起來我們的耳朵在睡覺時關掉了，但科學告訴我們，它們一直都在保持警惕。下次當你認為你的伴侶或孩子在房間里不能聽到你在說什么時，再想想。