How does your brain respond to pain? - Karen D. Davis

你的大腦如何回應痛感？— 凱倫·戴維斯 (Karen D. Davis)

Translator: Jessica Ruby Reviewer: Caroline Cristal

譯者: Regina Chu 審譯者: Adrienne Lin

Let's say that it would take you ten minutes to solve this puzzle.

這麼說吧！如果你平常能以

十分鐘完成這幅拼圖

How long would it take

你要花多久才能完成

if you received constant electric shocks to your hands?

如果你的手不斷受到電擊？

Longer, right?

更久的時間，對吧？

Because the pain would distract you from the task.

因為痛會分散你對任務的注意力

Well, maybe not;

唔，不見得

it depends on how you handle pain.

要看你對痛的反應是什麼

Some people are distracted by pain.

有些人會因為痛而分心

It takes them longer to complete a task, and they do it less well.

他們要花更久的時間完成任務

而且他們做得也較差

Other people use tasks to distract themselves from pain,

另一些人則以任務 來分散他們對痛的注意力

and those people actually do the task

所以其實這些人做任務時

faster and better when they're in pain

在痛苦中的表現會比 不痛的時候更快更好

than when they're not.

Some people can just send their mind wandering

有些人就是可以讓他們的心智漫遊

to distract themselves from pain.

以分散他們對痛的注意力

How can different people

為什麼不同的人

be subjected to the exact same painful stimulus

在面對同樣的痛覺刺激時

and yet experience the pain so differently?

會經歷全然不同的反應？

And why does this matter?

而為什麼這很重要？

First of all, what is pain?

首先，什麼是痛？

Pain is an unpleasant sensory and emotional experience,

痛是一種不愉快的感覺及情緒經驗

associated with actual or potential tissue damage.

與實際或潛在的組織損傷有關

Pain is something we experience,

痛是我們主觀的經歷

so it's best measured by what you say it is.

所以最好的測量法 是我們自己說有多痛

Pain has an intensity;

痛有強度

you can describe it on a scale

你以量表來描述

from zero, no pain, to ten, the most pain imaginable.

從 0 不痛，到 10 最痛

But pain also has a character,

但是痛也有不同的種類

like sharp, dull, burning, or aching.

像是銳痛、鈍痛、灼痛或疼痛

What exactly creates these perceptions of pain?

到底是什麼讓我們產生對痛的知覺？

你受傷的時候

Well, when you get hurt,

special tissue damage-sensing nerve cells,

針對組織損傷感測的神經細胞

called nociceptors, fire and send signals

稱為痛覺受器會激發 且送出信號到脊髓

to the spinal cord and then up to the brain.

然後上傳到腦部

Processing work gets done by cells called neurons and glia.

傳輸處理的過程

由稱為神經元及神經膠的細胞完成

This is your Grey matter.

這就是你的灰質

And brain superhighways carry information as electrical impulses

而大腦超級高速公路承載資訊

以電脈衝方式

from one area to another.

從一處傳到另一處

This is your white matter.

這就是你的白質

The superhighway that carries pain information

一條超級高速公路承載痛的資訊

from the spinal cord to the brain

從脊髓傳到腦部

is our sensing pathway

則是我們的感測路徑

that ends in the cortex,

其終點在皮質

a part of the brain that decides what to do

它是大腦的一部分

在接受痛覺信號之後 由其決定要做出什麼反應

with the pain signal.

Another system of interconnected brain cells

互連腦細胞的另一種系統

called the salience network

稱做突顯網路

decides what to pay attention to.

則決定要注意什麼事

Since pain can have serious consequences,

因為痛會帶來非常嚴重的後果

the pain signal immediately activates the salience network.

痛覺信號會立刻活化

突顯網路

現在，你會集中注意力了

Now, you're paying attention.

The brain also responds to the pain

腦部也對痛覺作出反應

and has to cope with these pain signals.

也必須因應這些痛覺信號

So, motor pathways are activated

所以，運動路徑因此活化

to take your hand off a hot stove, for example.

譬如說，讓你的手從火燙的爐上縮回

But modulation networks are also activated

但是調節網路也會活化

that deliver endorphins and enkephalins,

以輸送腦內啡及腦素

chemicals released when you're in pain or during extreme exercise,

這些化學物質，使在你受痛

或在玩極限運動的時候

creating the runner's high.

產生所謂「跑者的愉悅感」

These chemical systems help regulate and reduce pain.

這些化學系統幫助調節及減低痛感

這些網路及路徑一同合作

All these networks and pathways work together

to create your pain experience,

產生你的痛覺體驗

to prevent further tissue damage,

以預防進一步的組織損傷

and help you to cope with pain.

及幫助你因應疼痛

This system is similar for everyone,

這個系統在每個人身上都很類似

but the sensitivity and efficacy of these brain circuits

但是這些腦迴路的敏感度及效力

determines how much you feel and cope with pain.

將決定你到底覺得有多痛 以及對痛產生什麼反應

This is why some people have greater pain than others

這就是為什麼有些人比較怕痛

and why some develop chronic pain

及為什麼有些人會產生慢性疼痛

that does not respond to treatment,

對治療毫無反應

while others respond well.

但其他人卻治療效果良好

Variability in pain sensitivities

痛覺敏感度的變異性

is not so different than all kinds of variability

與回應其它刺激的變異性

in responses to other stimuli.

其實相差不大

Like how some people love roller coasters,

就像為什麼有人愛雲霄飛車

but other people suffer from terrible motion sickness.

但有些人一坐就暈的七葷八素

Why does it matter that there is variability

為什麼在我們腦迴路

in our pain brain circuits?

有變異性是這麼重要？

Well, there are many treatments for pain,

嗯，我們有很多治療痛的方法

targeting different systems.

針對不同的系統下藥

For mild pain, non-prescription medications

對輕度疼痛，非處方藥

can act on cells where the pain signals start.

在痛覺信號一開始就對細胞作用

Other stronger pain medicines and anesthetics

其它更強的止痛藥及麻醉藥

work by reducing the activity in pain-sensing circuits

則減緩痛覺感測迴路

or boosting our coping system, or endorphins.

或增強我們的因應系統 即腦內啡

有些人應付疼痛

Some people can cope with pain using methods that involve

是用一些方法如

distraction, relaxation, meditation, yoga,

分心、放鬆、靜坐、瑜珈

or strategies that can be taught, like cognitive behavioral therapy.

或是用可以訓練的策略

像認知行為治療

對那些遭受嚴重慢性疼痛之苦的人

For some people who suffer from severe chronic pain,

that is pain that doesn't go away

也就是痛覺依然存在

months after their injury should have healed,

即使在他們所受的傷應該 已經痊癒的數月之後

none of the regular treatments work.

常規的藥石也是罔然

Traditionally, medical science has been about

醫學發展傳統上是在

testing treatments on large groups

大群人身上測試治療法

to determine what would help a majority of patients.

以找出對多數病人有幫助的方法

But this has usually left out

但是這通常會排除

some who didn't benefit from the treatment

對測試治療無效的人

or experienced side effects.

或經歷副作用的人

Now, new treatments that directly stimulate or block

現在，新的治療法以直接刺激或阻斷

certain pain-sensing attention or modulation networks

某些痛感測的注意力或調節網路

are being developed,

已在開發階段

along with ways to tailor them to individual patients,

同時也在為個別患者

using tools like magnetic resonance imaging

用核磁共振法

to map brain pathways.

繪出大腦各式路徑以量身打造藥物

找出你的大腦如何對疼痛反應

Figuring out how your brain responds to pain

is the key to finding the best treatment for you.

是找出對你最佳的治療法的關鍵

That's true personalized medicine.

那可真是有個性的藥啊！