運動真的能讓我們變聰明嗎大綱

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，經常鍛鍊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：體育鍛煉在提高認知能力方面顯現出來的益處，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後會“更聰明”，我們的大腦會不會做出相應的反應？對於想要通過鍛鍊來在一生中保持頭腦敏捷的人來說，這個問題的答案至關重要。

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.

在實驗科學中，最出色可靠的研究會把參與者隨機分爲兩組，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，因爲它們幫助科學家來控制受試者的預期。例如，如果人們相信一種藥物會產生某些效果，他們的身體可能就會出現相應的反應，即使志願者只是吃了外觀相似的無效藥物。這就是安慰劑效應，它的存在意味着，正在研究的藥物或療程並沒有看上去那麼有效；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，一些科學家開始懷疑，體育鍛煉表現出來的改善思維的益處可能是安慰劑效應。儘管許多研究顯示，運動或有提高認知能力的好處，但這些實驗都存在一種明顯的科學侷限性：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.

這個問題本身並不涉及什麼深奧的科學辯論。如果運動提高認知能力的益處是安慰劑效應，而不是大腦因爲運動發生了真正的改變，那麼這些好處可能就會轉瞬即逝，無法長期幫助我們記住“轉瞬即逝”這種複雜詞彙。

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。對於體育鍛煉來說，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州立大學(Florida State University)以及伊利諾伊大學厄巴納-香檳分校(University of Illinois at Urbana-Champaign)的研究人員想到了一個聰明的迂迴辦法。他們決定把關注點放在：受試者預期鍛鍊會對思維產生何種影響。如果他們的期待與實際的益處吻合，那麼至少部分好處很可能是源於安慰劑效應，而不是鍛鍊的結果。

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.

在早前對視頻遊戲與認知能力的關係所做的研究中，科學家們就遇到過這種情況。過去的研究顯示，玩動作類視頻遊戲可以改善玩家的思維能力。但當進行新研究的科學家們讓視頻遊戲玩家估計遊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後的認知測試的加分完全吻合。換句話說，玩視頻遊戲的認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.

關於鍛鍊的這項新研究上個月發表在《公共科學圖書館：綜合》期刊(PLOS One)上。研究人員重複了這個實驗，但把實驗內容換成了體育鍛煉。他們通過一個在線調查系統招募了171人，要求其中一半的志願者來評估，如果一週進行三次拉伸運動，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.

另一組志願者被問到同樣的問題，不過鍛鍊項目換成了有規律的步行運動。

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，志願者認爲，輕度拉伸對認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.

這些數據雖然沒有涉及真正的體育鍛煉，對於真正從事鍛鍊的人來說卻是個好消息。“我們的研究結果顯示，有氧運動的好處不是安慰劑效應，”佛羅里達州立大學的認知心理學研究生卡里·斯托塔特(Cary Stothart)說。他牽頭進行了這項研究。

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動研究中發現的鍛鍊對認知能力的改善，那麼受試者就應該是期待步行比拉伸更有益處。他們沒有，這就意味着體育鍛煉之後，大腦和思維能力真的發生了生理上的變化。

Of course, this study was small and involved a self-selected group of people who happen to like completing online surveys. Some said they exercised, others said they did not. None claimed to be familiar with the science related to exercise and the brain, but it is impossible to know if people were being forthright.

當然，這項研究的規模較小，參與者只涵蓋了喜歡完成網上調查的人。有些人聲稱自己平時鍛鍊，其他人則說自己不運動。沒人自稱熟悉與運動和大腦有關的科學，但也無法知道他們是不是都說了真話。

Still, the findings are strong enough to suggest that exercise really does change the brain and may, in the process, improve thinking, Mr. Stothart said. That conclusion should encourage scientists to look even more closely into how, at a molecular level, exercise remodels the human brain, he said. It also should spur the rest of us to move, since the benefits are, it seems, not imaginary, even if they are in our head.

不過，斯托塔特表示，這些發現仍然足以證明，鍛鍊真的會改變大腦，或許在這個過程中，還可能改善思維能力。他說，這個結論應該可以鼓勵科學家們進一步探索：在分子層面上，運動是如何重塑了我們的大腦。它還應該激勵我們其他人動起來，因爲看來這些益處並非想象出來的，雖然它們的確發生在我們的大腦裏。