Name: 【TED-Ed】想象力的神經科學--安德烈-維謝茲基(Andrey Vyshedskiy) (【TED-Ed】The neuroscience of imagination - Andrey Vyshedskiy)
Uploaded: 2021-01-14T06:57:59.000Z
Duration: 4 min 49 s

Imagine, for a second, a duck teaching a French class,

花個幾秒鐘想像一下 一隻鴨子在教法文課

a ping-pong match in orbit  around a black hole,

一場在黑洞旁軌道上的乒乓球賽

You probably haven't actually seen any of these things,

你也許從沒看過剛剛的任何一樣東西

How does your brain produce an image of something you've never seen?

你的大腦是怎麼產生出一張你從沒看過東西的畫面呢？

but that's only because  we're so used to doing it.

但那只是因為我們非常習慣於這件事了

It turns out that this is actually a complex problem

that requires sophisticated coordination inside your brain.

你的大腦中需要複雜的協調合作

That's because to create  these new, weird images,

your brain takes familiar pieces  and assembles them in new ways,

你的大腦需要取出相近的片段 再將他們用不同的方式組合起來

like a collage made  from fragments of photos.

就像利用各部份相片完成一幅拼貼畫作

The brain has to juggle a sea of thousands of electrical signals

大腦必須應付海一般成千上萬的電子訊號

getting them all to their destination at precisely the right time.

並在準確的時間點將他們放到各自的目的地

thousands of neurons  in your posterior cortex fire.

後皮質裡上千個神經元正受到激發

These neurons encode various  characteristics of the object:

這些神經元編碼出各種關於這樣東西的特性：

帶刺的、水果、咖啡色、綠色和黃色

This synchronous firing strengthens the connections between that set of neurons,

這個同步激發使的那些神經元彼此間的連結更強

linking them together into what's known as a neuronal ensemble,

讓他們結成了我們所知道的神經元集群

In neuroscience, this is called the Hebbian principle,

neurons that fire together wire together.

那些共同受到激發有所連結的神經元

假設過了一下子，你試圖去想像一個鳳梨

the whole ensemble will light up, assembling a complete mental image.

整個集群會亮起來並組合出一個完整的心理意象

Dolphins are encoded by a different neuronal ensemble.

海豚則會由不同神經元集群來編碼出來

is encoded by a neuronal ensemble  associated with it,

皆由一個神經元集群來產生與它相關的編碼

the neurons wired together by that synchronized firing.

藉由同時受到激發而使那些神經元連結在一起

But this principle doesn't explain the infinite number of objects

然而這個理論並無法解釋我們如何想像出無限多種物品

that we can conjure up in our imaginations without ever seeing them.

The neuronal ensemble for a dolphin balancing a pineapple doesn't exist.

"一隻海豚試圖平衡鳳梨"這樣的神經元集群並不存在

那麼，你為什麼能想像這個畫面呢？

One hypothesis,  called the Mental Synthesis Theory,

If the neuronal ensembles  for the dolphin and pineapple

如果海豚與鳳梨的兩個神經元集群

we can perceive the two separate objects as a single image.

我們便能在同一畫面中感知到兩個不同物品

But something in your brain  has to coordinate that firing.

但必須由你大腦中的某樣東西來協調這樣的激發

One plausible candidate  is the prefrontal cortex,

which is involved in  all complex cognitive functions.

因為它幾乎參與了所有複雜的認知行為

Prefrontal cortex neurons are connected to the posterior cortex

前額皮質中的神經元與後皮質連結在一起

by long, spindly cell extensions called neural fibers.

藉由長且纖細的組織延伸 稱之為神經纖維

The mental synthesis theory proposes that like a puppeteer pulling the strings,

心理合成理論認為如同木偶師操縱著繩子

the prefrontal cortex neurons send electrical signals

前額皮質神經元傳送出電子訊號

to multiple ensembles in the posterior cortex.

抵達數個後皮質中的神經元集群

If the neuronal ensembles are turned on at the same time,

若那些神經元群集能夠在同時受到激發

you experience the composite image just as if you'd actually seen it.

你就如真的看見一般想像出合成畫面

This conscious purposeful synchronization

這個感知有目的的藉由前額皮質

of different neuronal ensembles by the prefrontal cortex

signals would have to arrive at both neuronal ensembles at the same time.

are much farther away  from the prefrontal cortex than others.

有些神經元比其他前額皮質中的神經元遠的多

If the signals travel down both fibers at the same rate,

如果訊號以同樣速度在神經纖維中傳輸

You can't change the length  of the connections,

but your brain,  especially as it develops in childhood,

但你的大腦，特別是在孩童發展階段

does have a way to change  the conduction velocity.

Neural fibers are wrapped in a fatty substance called myelin.

神經纖維外層包裹著富含脂肪的物質稱為髓鞘

and speeds up the electrical signals  zipping down the nerve fiber.

可以加快電子訊號在神經纖維中的傳送速度

Some neural fibers have  as many as 100 layers of myelin.

有些神經纖維外甚至包著100層之多的髓鞘

那些包裹著較厚髓鞘層的神經纖維

can conduct signals  100 times faster or more

Some scientists now think that this difference in myelination

部份科學家開始認為這些髓鞘層的厚薄程度

could be the key  to uniform conduction time in the brain,

也許就是平衡大腦中傳導時間的關鍵

and consequently,  to our mental synthesis ability.

所以，對於我們心理合成的能力

A lot of this myelination  happens in childhood,

our vibrant imaginations may have a lot to do with building up brains

我們活躍的想像力對於建構大腦有很大的作用

can craft creative symphonies throughout our lives.