生命在于运动 健脑全靠锻炼
http://www.huanqiu.com 来源：环球网 进入论坛 2007-11-29 10:30
Exercise on the Brain
Feeling a little less mentally quick than you did a few years ago? Maybe you are among the many people who do “brain exercises” like sudoku to slow the cognitive decline associated with aging. We’ve got a better suggestion.
有没有感觉大脑反应比前几年迟钝了？也许你和许多人一样，为了延缓年龄渐长引起的认知能力衰退，时常进行“脑力锻炼”，比如玩数独游戏。但我们有一个更好的建议。
Computer programs to improve brain performance are a booming business. In the United States, consumers are expected to spend $80 million this year on brain exercise products, up from $2 million in 2005. Advertising for these products often emphasizes the claim that they are designed by scientists or based on scientific research. To be charitable, we might call them inspired by science — not to be confused with actually proven by science.
能提高大脑认知能力的电脑游戏正成为一个欣欣向荣的产业。在美国，预计消费者今年一年在脑力锻炼产品上的花费能达到8000万美元，而2005年，这一数字仅为200万美元。相关广告经常强调此类产品由科学家或基于科研成果而设计。实际上说得好听一些，它们至多是受了科学的启发，而非经过科学验证。
Environmental enrichment does improve mental function in laboratory animals. Rodents and monkeys that get playmates or toys learn to complete a variety of tasks more easily, at all ages. They also have larger brains, larger brain cells and more synaptic connections than animals raised alone in standard cages. But here’s the rub: standard laboratory environments are tremendously boring. Lab animals rarely need to search for food or avoid predators. In contrast, most of us get plenty of everyday stimulation in activities like finding a new address, socializing with friends or navigating the treacherous currents of office politics. Animal enrichment research may be telling us something important not about the positive effects of stimulation, but about reversing the negative effects of deprivation.
环境强化的确可以提高实验室动物的大脑认知能力。比起那些养在笼中的动物，处于各年龄段的啮齿目和猿类动物在有玩伴或得到玩具时更容易完成一系列任务。它们的脑体积更大，脑细胞及细胞结点更多。但上述试验的问题在于：标准的实验环境极其单一，实验室动物很少需要外出觅食或躲避天敌。相反，许多人都在日常生活中接受种种外部刺激，例如，查找一个新地址，与朋友交往，在办公室政治的险风恶浪中航行。动物强化试验不仅使我们了解到刺激的积极结果，更揭示出如何能转变刺激贫乏的负面影响。
Another line of evidence cited by marketers comes from studies of elderly people who improve certain skills by practicing a challenging computer-based task. Although most programs work to some extent, the gains tend to be specific to the trained task.
商家提出的另一项证据是，有研究表明，通过完成一项富于挑战的电脑游戏任务，老年人的某些技能有所提高。尽管多数游戏在某些程度上有所收效，但效果仅限于你所玩的那种游戏。
That is, practice can certainly make people better at sudoku puzzles or help them remember lists more accurately. The improvement can even last for years. Similarly, people tend to retain skills and knowledge they learned thoroughly when they were younger. Unless the activities span a broad spectrum of abilities, though, there seems to be no benefit to general mental fitness.
也就是说，练习当然能让你更擅长数独游戏，帮助你更准确地记忆清单，而且这种效果甚至能够持续多年。类似的是，年轻时学到的技能和知识往往会陪伴你很久。然而，除非某些活动所需的能力很多，否则对大脑的整体健康毫无裨益。
For people whose work is unstimulating, having mentally challenging hobbies, like learning a new language or playing bridge, can help maintain cognitive performance. But the belief that any single brain exercise program late in life can act as a quick fix for general mental function is almost entirely faith-based.
对于那些工作缺乏刺激的人而言，学习一门语言或打桥牌这样富于思维挑战的活动有助于保持认知能力。但认为老年时期所进行的某项脑力锻炼活动能快速改善大脑整体功能的想法完全是一厢情愿。
One form of training, however, has been shown to maintain and improve brain health — physical exercise. In humans, exercise improves what scientists call “executive function,” the set of abilities that allows you to select behavior that’s appropriate to the situation, inhibit inappropriate behavior and focus on the job at hand in spite of distractions. Executive function includes basic functions like processing speed, response speed and working memory, the type used to remember a house number while walking from the car to a party.
然而，有一种锻炼方法被证明能维持和改善大脑的健康状况——体育锻炼。就人类而言，体育锻炼能改善科学家所说的“执行功能”， 即一系列帮助人在特定场合选择与环境相宜的行为、控制不当行为以及在注意力分散的情况下仍能专注于手头工作的那些能力。执行功能包括如大脑处理速度、反应速度及运作记忆在内的一些基本功能。从车上下来走到一个聚会地点途中记忆的一个门牌号就属于运作记忆范畴。
Executive function starts to decline when people reach their 70s. But elderly people who have been athletic all their lives have much better executive function than sedentary people of the same age. This relationship might occur because people who are healthier tend to be more active, but that’s not the whole story. When inactive people get more exercise, even starting in their 70s, their executive function improves, as shown in a recent meta-analysis of 18 studies. One effective training program involves just 30 to 60 minutes of fast walking several times a week.
执行功能在70岁左右开始衰退。与不爱运动的同龄人相比，喜欢经常运动的老年人的执行功能较好。出现这种情况的原因可能在于身体健康的人更加活跃，但事实并非全部如此。最新一项针对18例研究的元分析显示：如果以前不爱运动的人加强锻炼，其执行功能也会得到改善——即使他们在70岁时才开始参加体育锻炼。一种有效的锻炼方式是每周数次快走30至60分钟。
Exercise is also strongly associated with a reduced risk of dementia late in life. People who exercise regularly in middle age are one-third as likely to get Alzheimer’s disease in their 70s as those who did not exercise. Even people who begin exercising in their 60s have their risk reduced by half.
锻炼还可大大降低老年期罹患早发性痴呆症的风险。中年时经常进行体育锻炼的人在70岁左右患此病的可能性仅为那些不锻炼的人的三分之一。即便到了60岁才开始锻炼，也可将这一风险降低一半。
How might exercise help the brain? In people, fitness training slows the age-related shrinkage of the frontal cortex, which is important for executive function. In rodents, exercise increases the number of capillaries in the brain, which should improve blood flow, and therefore the availability of energy, to neurons. Exercise may also help the brain by improving cardiovascular health, preventing heart attacks and strokes that can cause brain damage. Finally, exercise causes the release of growth factors, proteins that increase the number of connections between neurons, and the birth of neurons in the hippocampus, a brain region important for memory. Any of these effects might improve cognitive performance, though it’s not known which ones are most important.
锻炼究竟如何有益于大脑？就人类而言，锻炼能够减缓由年龄渐长引发的脑皮层萎缩，而脑皮层对大脑执行功能起着重要作用。就啮齿类动物而言，锻炼帮助增加脑部毛细管数目，这些物质有助于改善血流，进而为神经元提供能量。锻炼也许还能改善心血管健康状况，预防可能损伤大脑的心脏病及中风发生。锻炼亦能够引起增加脑神经元结点数目的生长因子及蛋白质的释放，促使脑内海马状突起——脑部记忆的重要区域——的生发。上述这些方面均可提高认知能力，但哪些因素更重要尚不得而知。
So instead of spending money on computer games or puzzles to improve your brain’s health, invest in a gym membership. Or just turn off the computer and go for a brisk walk.
因此，与其花钱购买电脑游戏或字谜游戏改善大脑健康状况，不如去健身房办张会员卡；或者干脆关掉电脑，出去快走几步。（沈珺）
