到底有多痛？一探大腦便可知！

by Rob Stein

Right now， when someone is in pain， their doctor has no way to know how bad it is except to ask them questions. Like， how it ranks on a 1）scale of one to ten. And Tor Wager of the University of Colorado says， thats often not good enough.

Tor Wager： We all have trouble 2）communicating our pain and other feelings under different 3）circumstances.

Many people just have a hard time finding the right words. Some 4）exaggerate how bad it is. Others are too 5）stoic—they 6）downplay their pain. And some are simply physically 7）incapable of explaining what theyre feeling at all.

Wager： Children and adults who cant fully report pain 8）accurately are particularly 9）vulnerable.

目前，在病人感覺到痛的時候，除了直接詢問本人的感受，醫(yī)生并沒有其他辦法了解情況有多糟糕。比如說，從一到十，疼痛的程度是第幾級。（美國）科羅拉多大學(xué)的托爾·韋杰表示，這種做法往往不夠好。

托爾·韋杰：我們很難在各種不同情況下清楚地表述自己的痛感和其他感受。

很多人總是很難找到合適的詞匯描述痛感。有些人會夸大痛感，另外一些人則太有忍耐力——他們提及痛楚時只會輕描淡寫。還有一些人從生理上根本無法說清楚自己的感受。

韋杰：小孩子以及不能準(zhǔn)確描述病痛的成年人特別容易出問題。

That includes people who， say， suffered a 10）stroke or are very sick. So， Wager and his 11）colleagues decided to see if they could measure pain 12）objectively using brain scans. In a series of experiments involving 114 adults， the researchers measured brain activity as they 13）administered pain with a special 14）device.

Wager： Its a computer-controlled 15）hot plate that goes on a persons arm or another part of the body. And it can produce a safe， very 16）reliable source of painful 17）input to the brain.

The first question was whether brain scans could tell how much pain the hot plate was causing. In a paper being published in The New England Journal of Medicine， Wager and his colleagues report what they found.

Wager： We can measure， fairly accurately， how much pain a person is experiencing. It is between 90 and 100 percent accurate.

But the researchers wanted to find out if the scans could do something even harder： Tell the difference between physical and emotional pain.

Wager： When people experience social pain—especially pain thats 18）elicited by a recent break-up and people feel 19）rejected in love—that produces a brain 20）pattern that looks 21）remarkably similar to the pattern elicited by physical pain.

那當(dāng)中包括中風(fēng)病人或重病患者。因此，韋杰及其同事決定看看他們能否利用腦部掃描客觀地測出疼痛程度。在一系列針對114名成年人進行的實驗中，研究者使用特殊裝置人為地控制試驗對象的痛楚，同時測量他們的腦部活動情況。

韋杰：這是一個由電腦控制的加熱板，我們把它放在實驗對象的手臂或者其他身體部位。它能產(chǎn)生一種安全且穩(wěn)定的疼痛源輸入大腦。

首要問題是腦部掃描能否表明加熱板到底造成了多大痛楚。韋杰與他的同事在《新英格蘭醫(yī)學(xué)雜志》上發(fā)表了一篇論文，介紹他們的發(fā)現(xiàn)。

韋杰：我們能相當(dāng)準(zhǔn)確地測量出人體的痛苦程度，準(zhǔn)確率達(dá)到90%乃至100%。

但是研究者們還想驗證掃描能否做到更困難的事情：將肉體上的疼痛與精神上的痛苦區(qū)分開來。

韋杰：當(dāng)人們經(jīng)歷人際關(guān)系上的傷痛——特別是最近分手或者在愛情上受到挫折所帶來的痛苦時，它所產(chǎn)生的腦部掃描圖像與肉體痛楚造成的圖像驚人地相似。

So for the next part of their experiment， the researchers studied only people who had recently been 22）dumped.

Wager： And they were—still felt rejected. And they werent over their…the break-up.

The researchers showed the 23）subjects pictures of the people who had broken their hearts and of people who were just friends， and compared what was going on in their brains when they used the computercontrolled hot plates on their arms.

Wager： We tested our physical pain 24）signature， our pattern， to see whether it was fooled into believing that the romantic rejection or social pain was like physical pain. And we found that it wasnt.

And the researchers went even further， showing that the scans could tell when a powerful 25）prescription 26）painkiller was working.

Wager： The hope is if we could 27）peer into peoples brains， we can understand that different kinds of pain are created by very different brain systems. And we can 28）tailor our treatments to those systems.

Other scientists praised the research. Lynn Webster is the president of the American Academy of Pain Medicine.

Lynn Webster： Its fascinating. For a long time， weve tried to find objective ways to measure pain and its been 29）elusive.

But Webster says brain scans for pain could be 30）misused. 31）Insurance companies might try to use them to deny paying for pain drugs. Some doctors might use them to question whether their patients are telling the truth， or instead of simply listening to their patients.

Webster： If a patient believes their doctor understands and cares about them and believes in their pain， that can have as much of a 30 percent 32）reduction in their pain. So this connection， this belief， can be 33）enormously powerful.

Tor Wager agrees that the scans should be used very carefully. Webster： The bad 34）scenario would be， you come in， in pain， the 35）physician scans your brain and says， “Well， we dont see the pain here， so we think its in your mind. We dont think its really pain.” I dont think that this kind of method can or should ever be used as a pain 36）lie detector.

Instead， Wager hopes the technology will open a helpful new window. Not only into how pain really works in the brain， but also other feelings as well.

于是在接下來的實驗當(dāng)中，他們針對最近被拋棄的人進行專項研究。

韋杰：他們……還是很有挫折感。他們還是放不下他們的……分手。

研究者向?qū)嶒瀸ο笳故静煌恼掌?，包括讓他們傷心的人，還有普通朋友，并將在此過程中的腦部活動結(jié)果與在他們手臂上使用電腦控制加熱板的結(jié)果進行對比。

韋杰：我們測試了肉體疼痛的特征，又測試了腦部掃描圖像，看看（腦部掃描）會否將戀愛挫折或者人際痛苦與肉體疼痛相混淆——我們發(fā)現(xiàn)并沒有出現(xiàn)這種情況。

研究者們甚至還更進一步，掃描結(jié)果可以顯示強效的處方止痛藥是否確實發(fā)揮功效。

韋杰：我們希望，如果可以窺探人們的大腦，我們就能明白到不同類型的痛苦是由迥然不同的大腦系統(tǒng)所產(chǎn)生的。我們就能根據(jù)不同的系統(tǒng)對癥下藥了。

其他科學(xué)家高度贊揚了這項研究。林恩·韋伯斯特是美國病痛醫(yī)學(xué)研究院的院長。

林恩·韋伯斯特：這太了不起了。長期以來，我們一直試圖找到能客觀測量痛感的方法，卻總是難以實現(xiàn)。

不過韋伯斯特同時指出，腦部掃描也有可能被有意誤用。保險公司也許會根據(jù)掃描結(jié)果而拒絕為止痛藥買單。有些醫(yī)生也許會以此質(zhì)疑病人是否撒謊，而不再聆聽病人的感受。

韋伯斯特：如果病人相信醫(yī)生能理解他的病痛，關(guān)心他的痛楚，相信他有多難受，這種信念可以讓病人的痛苦減少三成。所以這種醫(yī)患之間的聯(lián)系——這種信念可以帶來巨大的力量。

托爾·韋杰也認(rèn)為腦部掃描的使用應(yīng)當(dāng)相當(dāng)謹(jǐn)慎。

韋伯斯特：糟糕的情況也許會是這樣——你痛得要去看病，醫(yī)生掃描了你的大腦，然后說：“喔，我們沒看見疼痛的圖像，所以我們認(rèn)為這是你的情緒作怪，不是真的病痛。”我認(rèn)為這種方式不可以——也不應(yīng)該作為“病痛測謊儀”使用。

韋杰則希望這項技術(shù)能夠開啟一扇有益、嶄新的窗戶，讓我們不僅看到病痛在大腦中如何作用，還能推而廣之，研究其他情緒感受。