到底有多痛？一探大脑便可知！

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，在病人感觉到痛的时候，除了直接询问本人的感受，医生并没有其他办法了解情况有多糟糕。比如说，从一到十，疼痛的程度是第几级。（美国）科罗拉多大学的托尔·韦杰表示，这种做法往往不够好。

托尔·韦杰：我们很难在各种不同情况下清楚地表述自己的痛感和其他感受。

很多人总是很难找到合适的词汇描述痛感。有些人会夸大痛感，另外一些人则太有忍耐力——他们提及痛楚时只会轻描淡写。还有一些人从生理上根本无法说清楚自己的感受。

韦杰：小孩子以及不能准确描述病痛的成年人特别容易出问题。

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.

那当中包括中风病人或重病患者。因此，韦杰及其同事决定看看他们能否利用脑部扫描客观地测出疼痛程度。在一系列针对114名成年人进行的实验中，研究者使用特殊装置人为地控制试验对象的痛楚，同时测量他们的脑部活动情况。

韦杰：这是一个由电脑控制的加热板，我们把它放在实验对象的手臂或者其他身体部位。它能产生一种安全且稳定的疼痛源输入大脑。

首要问题是脑部扫描能否表明加热板到底造成了多大痛楚。韦杰与他的同事在《新英格兰医学杂志》上发表了一篇论文，介绍他们的发现。

韦杰：我们能相当准确地测量出人体的痛苦程度，准确率达到90%乃至100%。

但是研究者们还想验证扫描能否做到更困难的事情：将肉体上的疼痛与精神上的痛苦区分开来。

韦杰：当人们经历人际关系上的伤痛——特别是最近分手或者在爱情上受到挫折所带来的痛苦时，它所产生的脑部扫描图像与肉体痛楚造成的图像惊人地相似。

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.

于是在接下来的实验当中，他们针对最近被抛弃的人进行专项研究。

韦杰：他们……还是很有挫折感。他们还是放不下他们的……分手。

研究者向实验对象展示不同的照片，包括让他们伤心的人，还有普通朋友，并将在此过程中的脑部活动结果与在他们手臂上使用电脑控制加热板的结果进行对比。

韦杰：我们测试了肉体疼痛的特征，又测试了脑部扫描图像，看看（脑部扫描）会否将恋爱挫折或者人际痛苦与肉体疼痛相混淆——我们发现并没有出现这种情况。

研究者们甚至还更进一步，扫描结果可以显示强效的处方止痛药是否确实发挥功效。

韦杰：我们希望，如果可以窥探人们的大脑，我们就能明白到不同类型的痛苦是由迥然不同的大脑系统所产生的。我们就能根据不同的系统对症下药了。

其他科学家高度赞扬了这项研究。林恩·韦伯斯特是美国病痛医学研究院的院长。

林恩·韦伯斯特：这太了不起了。长期以来，我们一直试图找到能客观测量痛感的方法，却总是难以实现。

不过韦伯斯特同时指出，脑部扫描也有可能被有意误用。保险公司也许会根据扫描结果而拒绝为止痛药买单。有些医生也许会以此质疑病人是否撒谎，而不再聆听病人的感受。

韦伯斯特：如果病人相信医生能理解他的病痛，关心他的痛楚，相信他有多难受，这种信念可以让病人的痛苦减少三成。所以这种医患之间的联系——这种信念可以带来巨大的力量。

托尔·韦杰也认为脑部扫描的使用应当相当谨慎。

韦伯斯特：糟糕的情况也许会是这样——你痛得要去看病，医生扫描了你的大脑，然后说：“喔，我们没看见疼痛的图像，所以我们认为这是你的情绪作怪，不是真的病痛。”我认为这种方式不可以——也不应该作为“病痛测谎仪”使用。

韦杰则希望这项技术能够开启一扇有益、崭新的窗户，让我们不仅看到病痛在大脑中如何作用，还能推而广之，研究其他情绪感受。