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  • You probably don't need to be told how important your brain is.

    你大概不需要別人 告訴你大腦有多重要

  • After all, every single thing you experience,

    畢竟,你經歷的每件事

  • your thoughts and your actions,

    你的思想、你的行動

  • your perceptions and your memories

    你的知覺、你的記憶

  • are processed here in your body's control center.

    都在你體內的這個控制中心處理

  • But if this already seems like a lot for a single organ to handle,

    如果這對單一器官而言 工作似乎太多了

  • it's actually only a small part of what the brain does.

    其實這還只是腦部工作的一小部分

  • Most of its activities are ones you'd never be aware of,

    大部分的腦部活動 都在你無意識的狀態下進行

  • unless they suddenly stopped.

    除非這些活動突然停止

  • The brain is made up of billions of neurons,

    腦由無數的神經元

  • and trillions of connections.

    及數不清的連接點組成

  • Neurons can be activated by specific stimuli or thoughts,

    神經元可由特定的刺激或思想活化

  • but they are also often spontaneously active.

    但也常常有自發性活動

  • Some fire cyclically in a set pattern.

    有些會以固定模式產生週期性發射

  • Others fire rapidly in short bursts before switching off,

    有些則在關閉前產生短暫猝發

  • or remain quiet for long periods

    還有一些是保持安靜很長一段時間

  • until thousands of inputs from other neurons line up in just the right way.

    直到從其它神經元輸入的無數訊號 以正確的方式排列才發射

  • On a large scale,

    大規模看

  • this results in elaborate rhythms of internally generated brain activity,

    這會使內部產生的 腦部活動產生複雜節律

  • humming quietly in the background

    在背景輕輕作響

  • whether we're awake, asleep,

    無論我們是醒著、睡著

  • or trying not to think about anything at all.

    還是試圖放空都這樣響著

  • And these spontaneously occurring brain functions

    這些自發性的腦部功能

  • form the foundation upon which all other brain functions rely.

    成為其它腦部活動的依賴基礎

  • The most crucial of these automatically occurring activities

    這些自發活動中最重要的

  • are the ones that keep us alive.

    是使我們活著的活動

  • For example, while you've been paying attention to this video

    舉例來說 就在你專心看這段影片的同時

  • spontaneous activity in your brain has been maintaining your breathing

    你腦部的自發活動 就在讓你保持呼吸

  • at 12 to 16 breaths a minute, making sure that you don't suffocate.

    每分鐘 12 到 16 次 確保你沒有窒息

  • Without any conscious effort,

    無需任何意識

  • signals from parts of your brainstem are sent through the spinal cord

    從腦幹傳來的訊號會經過脊髓

  • to the muscles that inflate your lungs,

    送到肌肉,使你的肺充氣

  • making them expand and contract, whether or not you're paying attention.

    無論你有沒有注意 都會使肺部擴張收縮

  • The neuronal circuits underlying such rhythmic spontaneous activity

    潛藏在此種節律自發 活動底下的神經元電路

  • are called central pattern generators,

    稱為中樞模式發生器

  • and control many simple repetitive behaviors,

    並控制許多簡單、重複的行為

  • like breathing,

    例如呼吸

  • walking,

    走路

  • and swallowing.

    及吞嚥

  • Ongoing neural activity also underlies our sensory perception.

    不斷進行的神經活動 也藏在我們的知覺下

  • It may seem

    雖然看起來像是

  • that the neurons in your retina that translate light into neural signals

    視網膜的神經元 將光轉變成神經訊號

  • would remain quiet in the dark,

    而此訊號在黑暗下會保持安靜

  • but in fact,

    但事實是

  • the retinal ganglion cells that communicate with the brain

    與大腦溝通的視網膜神經節細胞

  • are always active.

    永遠處在活化狀態下

  • And the signals they send are increases and decreases in the rate of activity,

    它們傳出的訊號隨活動增加或減少

  • rather than separate bursts.

    而非分開的猝發

  • So at every level, our nervous system is teeming with spontaneous activity

    所以我們的神經系統在每個層面 都充滿了自發性的活動

  • that helps it interpret and respond to any signals it might receive.

    幫助系統闡釋接受的訊號並做出反應

  • And our brain's autopilot isn't just limited to our basic biological functions.

    我們腦部的自動駕駛 可不只限於基礎生物功能

  • Have you ever been on the way home,

    你可曾在回家路上

  • started thinking about what's for dinner,

    想晚餐要吃什麼

  • and then realized you don't remember walking for the past five minutes?

    然後突然意識到 你不記得這五分鐘在走路?

  • While we don't understand all the details,

    雖然我們並不了解所有的細節

  • we do know that the ongoing activity in multiple parts of your brain

    我們的確知道在你腦中 數個部位的持續活動

  • is somehow able to coordinate what is actually a complex task

    以某種方式協調複雜的

  • involving both cognitive and motor functions,

    認知及運動功能任務

  • guiding you down the right path and moving your legs

    即使你在想晚餐要吃什麼

  • while you're getting dinner figured out.

    還是能帶你走對的路、移動腳

  • But perhaps the most interesting thing about spontaneous brain function

    但是自發性腦部功能最有趣的部分

  • is its involvement in one of the most mysterious

    大概是其與身體中最神秘

  • and poorly understood phenomena of our bodies: sleep.

    最不為人知的現象的關聯:睡眠

  • You may shut down and become inactive at night,

    你可能晚上睡死了動也不動

  • but your brain doesn't.

    但是你的腦部可不是這樣

  • While you sleep,

    你睡覺的時候

  • ongoing spontaneous activity gradually becomes more and more synchronized,

    持續進行的自發性活動 逐漸變得愈來愈同步

  • eventually developing into large, rhythmic neural oscillations

    最終變成大型節律神經震盪

  • that envelop your brain.

    籠罩你的腦部

  • This transition to the more organized rhythms of sleep

    這種轉變成更有規律的睡眠節律過程

  • starts with small clusters of neurons tucked in the hypothalamus.

    始於擠在海馬區裡的一小叢神經元

  • Despite their small number,

    儘管數量很少

  • these neurons have a huge effect

    這些神經元對關閉 平常讓你清醒和警覺的腦幹區域

  • in turning off brainstem regions that normally keep you awake and alert,

    有極大的效力

  • letting other parts, like the cortex and thalamus,

    使其它部位如皮質及視丘

  • slowly slip into their own default rhythms.

    慢慢轉成原本預設的節律

  • The deeper we fall into sleep,

    我們睡得愈熟

  • the slower and more synchronized this rhythm becomes,

    這種節律就愈慢且愈同步

  • with the deepest stages dominated by large amplitude, low frequency delta waves.

    最深層階段的睡眠則由 大振幅低頻率的德爾塔波控制

  • But surprisingly, in the middle of this slow wave sleep,

    但令人驚訝的是 在這種慢波睡眠期間

  • the brain's synchronized spontaneous activity

    腦部的同步自發性活動

  • repeatedly transitions into the sort of varied bursts

    又轉變成在我們完全清醒時

  • that occur when we're wide awake.

    才會發生的各式猝發

  • This is the sleep stage known as REM sleep,

    這個階段稱為快速動眼期

  • where our eyes move rapidly back and forth as we dream.

    此時我們的眼球會快速 來回移動,還會作夢

  • Neuroscientists are still trying to answer many fundamental questions about sleep,

    神經科學家仍然試著找出 睡眠基礎問題的答案

  • such as its role in rejuvenating cognitive capacity,

    譬如它如何恢復認知能力

  • cellular homeostasis,

    細胞穩態

  • and strengthening memory.

    及強化記憶

  • And more broadly, they are exploring

    他們還更廣泛地探索

  • how it is that brain can accomplish such important and complex tasks,

    腦部如何能完成如此 重要又複雜的工作

  • such as driving, or even breathing, without our awareness.

    如無意識的開車甚至呼吸

  • But for now, until we are better able

    但是現在,在我們能更進一步

  • to understand the inner workings of their spontaneous functioning,

    瞭解腦部自發性功能 內部如何運作前

  • we need to give our brains credit for being much smarter

    我們必須承認我們的腦部

  • than we ourselves are.

    比我們自己要聰明多了

You probably don't need to be told how important your brain is.

你大概不需要別人 告訴你大腦有多重要

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B1 中級 中文 美國腔 TED-Ed 腦部 活動 節律 神經元 訊號

【TED-Ed】自發性大腦活動如何維持生命 (How spontaneous brain activity keeps you alive - Nathan S. Jacobs)

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    稲葉白兎 發佈於 2015 年 06 月 21 日
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