运动真的能让我们变聪明吗

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.
体育锻炼似乎对大脑有益，最近的许多研究表明，经常锻炼可以改善记忆和思维能力。但一项有趣的新研究却提出了这样的问题：体育锻炼在提高认知能力方面显现出来的益处，是真实存在，还是心理作用？也就是说，假如我们相信自己在运动之后会“更聪明”，我们的大脑会不会做出相应的反应？对于想要通过锻炼来在一生中保持头脑敏捷的人来说，这个问题的答案至关重要。

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.
在实验科学中，最出色可靠的研究会把参与者随机分为两组，一组得到正在研究的药物或治疗方法，另一组得到的则是无效的安慰剂，其外观与第一组拿到的药物类似，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.
安慰剂很重要，因为它们帮助科学家来控制受试者的预期。例如，如果人们相信一种药物会产生某些效果，他们的身体可能就会出现相应的反应，即使志愿者只是吃了外观相似的无效药物。这就是安慰剂效应，它的存在意味着，正在研究的药物或疗程并没有看上去那么有效；有些效果是由人们的期待促成的，而不是药物本身。

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，一些科学家开始怀疑，体育锻炼表现出来的改善思维的益处可能是安慰剂效应。尽管许多研究显示，运动或有提高认知能力的好处，但这些实验都存在一种明显的科学局限性：它们没有使用对照组。

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.
这个问题本身并不涉及什么深奥的科学辩论。如果运动提高认知能力的益处是安慰剂效应，而不是大脑因为运动发生了真正的改变，那么这些好处可能就会转瞬即逝，无法长期帮助我们记住“转瞬即逝”这种复杂词汇。

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，研究这个问题却很困难。对于体育锻炼来说，不存在无效对照剂，也没有办法不让受试者知道自己是不是在运动。他们清楚自己有没有步行或骑自行车。

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，来自塔拉哈西的佛罗里达州立大学(Florida State University)以及伊利诺伊大学厄巴纳-香槟分校(University of Illinois at Urbana-Champaign)的研究人员想到了一个聪明的迂回办法。他们决定把关注点放在：受试者预期锻炼会对思维产生何种影响。如果他们的期待与实际的益处吻合，那么至少部分好处很可能是源于安慰剂效应，而不是锻炼的结果。