Name: 【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)
Uploaded: 2015-06-21T16:00:50.000Z
Duration: 5 min 18 s

情態副詞

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,

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

The brain is made up  of billions of neurons,

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.

有些會以固定模式產生週期性發射

Others fire rapidly in short bursts  before switching off,

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

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

or trying not to think  about anything at all.

And these spontaneously  occurring brain functions

form the foundation upon which all other brain functions rely.

The most crucial of these automatically occurring activities

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

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

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

and control many  simple repetitive behaviors,

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

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

the retinal ganglion cells  that communicate with the brain

與大腦溝通的視網膜神經節細胞

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

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

started thinking  about what's for dinner,

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,

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

involving both cognitive  and motor functions,

guiding you down the right path and moving your legs

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

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,

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

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

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,

letting other parts,  like the cortex and thalamus,

slowly slip into their  own default rhythms.

the slower and more synchronized this rhythm becomes,

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

repeatedly transitions into the sort of varied bursts

This is the sleep stage known as REM sleep,

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,

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.

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

字幕列表影片播放

【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)

cognitive

pattern

brain

attention