運動真的能讓我們變聰明嗎?

Does Exercise Really Make Us Smarter?

運動真的能讓我們變聰明嗎?

Exercise seems to be good for the human brain, with many recent studies suggesting that regular exercise improves memory and thinking skills. But an interesting new study asks whether the apparent cognitive benefits from exercise are real or just a placebo effect — that is, if we think we will be “smarter” after exercise, do our brains respond accordingly? The answer has significant implications for any of us hoping to use exercise to keep our minds sharp throughout our lives.

體育鍛煉似乎對大腦有益，最近的許多研究表明，經(jīng)常鍛煉可以改善記憶和思維能力。但一項有趣的新研究卻提出了這樣的問題：體育鍛煉在提高認(rèn)知能力方面顯現(xiàn)出來的益處，是真實存在，還是心理作用?也就是說，假如我們相信自己在運動之后會“更聰明”，我們的大腦會不會做出相應(yīng)的反應(yīng)?對于想要通過鍛煉來在一生中保持頭腦敏捷的人來說，這個問題的答案至關(guān)重要。

In experimental science, the best, most reliable studies randomly divide participants into two groups, one of which receives the drug or other treatment being studied and the other of which is given a placebo, similar in appearance to the drug, but not containing the active ingredient.

在實驗科學(xué)中，最出色可靠的研究會把參與者隨機分為兩組，一組得到正在研究的藥物或治療方法，另一組得到的則是無效的安慰劑，其外觀與第一組拿到的藥物類似，但不含活性成分。

Placebos are important, because they help scientists to control for people’s expectations. If people believe that a drug, for example, will lead to certain outcomes, their bodies may produce those results, even if the volunteers are taking a look-alike dummy pill. That’s the placebo effect, and its occurrence suggests that the drug or procedure under consideration isn’t as effective as it might seem to be; some of the work is being done by people’s expectations, not by the medicine.

安慰劑很重要，因為它們幫助科學(xué)家來控制受試者的預(yù)期。例如，如果人們相信一種藥物會產(chǎn)生某些效果，他們的身體可能就會出現(xiàn)相應(yīng)的反應(yīng)，即使志愿者只是吃了外觀相似的無效藥物。這就是安慰劑效應(yīng)，它的存在意味著，正在研究的藥物或療程并沒有看上去那么有效;有些效果是由人們的期待促成的，而不是藥物本身。

Recently, some scientists have begun to question whether the apparently beneficial effects of exercise on thinking might be a placebo effect. While many studies suggest that exercise may have cognitive benefits, those experiments all have had a notable scientific limitation: They have not used placebos.

最近，一些科學(xué)家開始懷疑，體育鍛煉表現(xiàn)出來的改善思維的益處可能是安慰劑效應(yīng)。盡管許多研究顯示，運動或有提高認(rèn)知能力的好處，但這些實驗都存在一種明顯的科學(xué)局限性：它們沒有使用對照組。

This issue is not some abstruse scientific debate. If the cognitive benefits from exercise are a result of a placebo effect rather than of actual changes in the brain because of the exercise, then those benefits could be ephemeral and unable in the long term to help us remember how to spell ephemeral.

這個問題本身并不涉及什么深奧的科學(xué)辯論。如果運動提高認(rèn)知能力的益處是安慰劑效應(yīng)，而不是大腦因為運動發(fā)生了真正的改變，那么這些好處可能就會轉(zhuǎn)瞬即逝，無法長期幫助我們記住“轉(zhuǎn)瞬即逝”這種復(fù)雜詞匯。

Studying this issue, however, is difficult. There is no placebo for exercise and no way to blind people about whether they are exercising. They know if they are walking or cycling or not.

然而，研究這個問題卻很困難。對于體育鍛煉來說，不存在無效對照劑，也沒有辦法不讓受試者知道自己是不是在運動。他們清楚自己有沒有步行或騎自行車。

So researchers at Florida State University in Tallahassee and the University of Illinois at Urbana-Champaign came up with a clever workaround. They decided to focus on expectations, on what people anticipate that exercise will do for thinking. If people’s expectations jibe closely with the actual benefits, then at least some of those improvements are probably a result of the placebo effect and not of exercise.

因此，來自塔拉哈西的佛羅里達(dá)州立大學(xué)(Florida State University)以及伊利諾伊大學(xué)厄巴納-香檳分校(University of Illinois at Urbana-Champaign)的研究人員想到了一個聰明的迂回辦法。他們決定把關(guān)注點放在：受試者預(yù)期鍛煉會對思維產(chǎn)生何種影響。如果他們的期待與實際的益處吻合，那么至少部分好處很可能是源于安慰劑效應(yīng)，而不是鍛煉的結(jié)果。

The scientists had seen this situation at work during an earlier study of video games and cognition. Past research had suggested that playing action-oriented video games improves players’ subsequent thinking skills. But when scientists in the new study asked video-game players to estimate by how much the games would improve their thinking, the players’ estimates almost exactly matched the gains seen on cognitive tests after playing. In other words, the cognitive benefits of playing video games appear to be largely a result of a placebo effect.

在早前對視頻游戲與認(rèn)知能力的關(guān)系所做的研究中，科學(xué)家們就遇到過這種情況。過去的研究顯示，玩動作類視頻游戲可以改善玩家的思維能力。但當(dāng)進(jìn)行新研究的科學(xué)家們讓視頻游戲玩家估計游戲能在多大程度上改善他們的思維能力時，玩家的估計幾乎和玩后的認(rèn)知測試的加分完全吻合。換句話說，玩視頻游戲的認(rèn)知好處似乎主要是心理作用。

For the new study, which was published last month in PLOS One, the researchers repeated this experiment but focused on exercise. Recruiting 171 people through an online survey system, they asked half of these volunteers to estimate by how much a stretching and toning program performed three times a week might improve various measures of thinking, including memory and mental multitasking.

關(guān)于鍛煉的這項新研究上個月發(fā)表在《公共科學(xué)圖書館：綜合》期刊(PLOS One)上。研究人員重復(fù)了這個實驗，但把實驗內(nèi)容換成了體育鍛煉。他們通過一個在線調(diào)查系統(tǒng)招募了171人，要求其中一半的志愿者來評估，如果一周進(jìn)行三次拉伸運動，能夠在多大程度上改善思維能力，比如記憶力和一心多用的能力。

The other volunteers were asked the same questions, but about a regular walking program.

另一組志愿者被問到同樣的問題，不過鍛煉項目換成了有規(guī)律的步行運動。

In actual experiments, stretching and toning regimens generally have little if any impact on people’s cognitive skills. Walking, on the other hand, seems to substantially improve thinking ability.

在真實的實驗中，拉伸運動基本上對認(rèn)知能力沒有多少影響。另一方面，散步則顯示出能大幅改善思維能力。

But the survey respondents believed the opposite, estimating that the stretching and toning program would be more beneficial for the mind than walking. The volunteers’ estimates of the likely cognitive improvements from gentle toning averaged about a three on a scale from one to six. The estimates of benefits from walking were lower.

不過，在這項實驗中，受試者的想法則正好相反。他們估計拉伸項目比步行對大腦更有益處。以1到6級來衡量，志愿者認(rèn)為，輕度拉伸對認(rèn)知的潛在改善的平均等級是3。他們對步行的評估則低一些。

These data, while they do not involve any actual exercise, are good news for people who do exercise. “The results from our study suggest that the benefits of aerobic exercise are not a placebo effect,” said Cary Stothart, a graduate student in cognitive psychology at Florida State University, who led the study.

這些數(shù)據(jù)雖然沒有涉及真正的體育鍛煉，對于真正從事鍛煉的人來說卻是個好消息。“我們的研究結(jié)果顯示，有氧運動的好處不是安慰劑效應(yīng)，”佛羅里達(dá)州立大學(xué)的認(rèn)知心理學(xué)研究生卡里·斯托塔特(Cary Stothart)說。他牽頭進(jìn)行了這項研究。

If expectations had been driving the improvements in cognition seen in studies after exercise, Mr. Stothart said, then people should have expected walking to be more beneficial for thinking than stretching. They didn’t, implying that the changes in the brain and thinking after exercise are physiologically genuine.

斯托塔特解釋，假如是人們的期待在驅(qū)動研究中發(fā)現(xiàn)的鍛煉對認(rèn)知能力的改善，那么受試者就應(yīng)該是期待步行比拉伸更有益處。他們沒有，這就意味著體育鍛煉之后，大腦和思維能力真的發(fā)生了生理上的變化。