科学美国人60秒：疼痛预期会影响疼痛体验

燕山大学 刘立军 编写

u TRANSCRIPT

This is Scientific American - 60-Second Science. I'm Karen Hopkin.

Getting a vaccine can be a painful experience, especially when you're a kid. But getting told the shot might "hurt a bit" could actually make it worse.

"We know that expectation affects pain experience in adults. But we don't really know whether this is also true for children."

Kalina Michalska, a developmental neuroscientist at the University of California, Riverside. She led a study to find out.

The study included 25 adults and 48 children. And 27 of the kids had a pre-existing anxiety disorder. Because medical procedures make pretty much all kids anxious... and those who are anxious to start with tend to find the experience even more painful.

The researchers used a handheld wand to apply heat to the forearm of each participant. And they asked subjects to rate the temperature in terms of discomfort. The hottest setting was about the temperature of very warm tap water - uncomfortable, perhaps, but not damaging.

"But during the experiment, we were most interested in only one temperature: the one that each subject rated as medium."

That's where the "anticipation" part of the experiment comes in. Subjects were played one of two tones. "One tone meant that low heat was coming; the other meant that high heat was upcoming." But here's the sneaky part. No matter what tone was played, participants got the same heat applied - the one rated as "medium." "So even though the subject heard a cue indicating high pain or low pain, the pain was only medium."

Or at least that's how it should have felt. But what happened was that subjects reported feeling what they thought they would.

"If we tell them through this tone that they're going to experience a lot of pain, they'll actually experience more pain: they rated the pain as higher. And conversely, if we tell them that they will experience only low pain, they also rate their experiences as less painful."

"This is really important because it kind of reinforces the necessity of not hyping up painful experiences. And also discouraging children from ramping up the experience in their head."

And the same, it seems, goes for the grownups.

"One aspect surprised us, was that all three groups experienced a similar relationship between pain expectation and pain experience. We expected the strongest correlation among anxious children. But however all three groups showed a very large effect of expectancy on their experience of pain."

The research is in the journal Psychosomatic Medicine.

Next up, Michalska says she'd like to examine whether negative associations can be unlearned. So next time you need a shot, remember: if you think it won't be so bad, maybe it won't be.

Thanks for listening for Scientific American - 60-Second Science. I'm Karen Hopkin.

Adapted from http://www.kekenet.com/broadcast/201812/571827.shtml

u VOCABULARY

1. neuroscience n. (不可数名词) the science that deals with the structure and function of the brain and the nervous system 神经科学 (派生词) neuroscientist神经科学家

2. wand n. any object in the shape of a straight thin stick 棍；棒；杆；杖。例如：a mascara wand

睫毛膏棒

3. hype up: 煽动; 使兴奋。例如：To hype someone up means to deliberately make them very excited about something. 例如：Everyone at school used to hype each other up about men all the time. 过去在学校大家经常相互煽动彼此对男人的兴趣。

4. rampe sth. up: to make sth. increase in amount使…的数量增加

u QUESTIONS

Read the statements. Then listen to the news and check the true (ü) or false (û) statements.

q 1. Getting a vaccine can be a painful experience, especially when you're a kid.

q 2. The study included 27 adults and 48 children. And 27 of the kids had a pre-existing anxiety disorder.

q 3. The researchers used a handheld wand to apply heat to the forehead of each participant.

q 4. The sneaky part is no matter what tone was played, participants got the different heat applied.

q 5. One aspect, all three groups experienced a similar relationship between pain expectation and pain experience, surprised us.

q 6. Next time you need a shot, if you think it won't be so bad, maybe it won't be.

q 7. Expectation affects pain experience. This is true for both adults and children.

u KEY

Read the statements. Then listen to the news and check the true (ü) or false (û) statements.

þ 1. Getting a vaccine can be a painful experience, especially when you're a kid.

ý 2. The study included 27 adults and 48 children. And 27 of the kids had a pre-existing anxiety disorder. (正确表达) The study included 25 adults and 48 children. And 27 of the kids had a pre-existing anxiety disorder.

ý 3. The researchers used a handheld wand to apply heat to the forehead of each participant. (正确表达) The researchers used a handheld wand to apply heat to the forearm of each participant.

ý 4. The sneaky part is no matter what tone was played, participants got the different heat applied. (正确表达) The sneaky part is no matter what tone was played, participants got the same heat applied.

þ 5. One aspect, all three groups experienced a similar relationship between pain expectation and pain experience, surprised us.

þ 6. Next time you need a shot, if you think it won't be so bad, maybe it won't be.

þ 7. Expectation affects pain experience. This is true for both adults and children.