Train Your Brain: How to Keep Your Mind Young

By Camilla Cavendish

“Beep!” This is one of the most maddening computer games I've ever played. I'm tracking a f lock of birds, and when I hit the right one, it explodes with a satisfying “phut.” But as I get better at spotting them, the birds scatter1. scatter: 散布，布满。ever more wildly across the screen, and I hear that unforgiving “beep”: You missed.

Frankly, I feel like giving up. But many players don't dare. For this is HawkEye2. HawkEye: 这里是游戏名， haw keye本义为目光锐利的人。, a brain-training programme that claims it can sharpen my brain beyond simply getting faster at mouse-clicking. Trials have found that older people who play enough hours of this particular kind of game have few er car crashes—and even, apparently, a low er risk of dementia3. dementia: 痴呆（症）。.

Not so long ago, people thought boys were naturally better than girls at science. We may be making a similar mistake w hen w e assume older people

人们曾经认为，大脑在成年之后就会定型，并且随着年龄的衰老而衰退，不可避免地出现记忆力减退、学习能力下降等症状。然而近几年来，神经科学家发现，人类大脑有着终身的“神经可塑性”。如果我们通过适当的方法给大脑以科学的认知刺激，增强其学习能力，就能保持大脑的年轻和健康状态。方法为何？答案在文中揭晓。can't learn as w ell as younger ones. Until recently, we thought that the brain cells w e w ere born w ith w ere a lifetime quota4. quota: 定额，配额。and that brains became f ixed in adulthood. But in the past decade, with the help of MRI scans and experiments on mice and monkeys, neuroscientists have demonstrated comprehensively that the human brain remains plastic throughout life.5. MRI: 磁共振成像；neuroscientist: 神经系统科学家；comprehensively: 全面地，广泛地；plastic: 可塑的。

When I set out to write a book about the burgeoning numbers of older people in the world, and the challenges they bring, I kept coming across data which suggested that we are far too fatalistic about many aspects of longer lives.6. 当我着手写一本关于全球老年人口数量激增及其带来的种种难题的书时，我得到的大量数据表明，我们对于更长寿命的许多方面的认知都过于绝对。burgeoning: 迅速增长的；come across: 碰到；fatalistic: 宿命论的。Many of us can now look forw ard to an extended middle-age lasting well into our seventies, even beyond. The incidence7. incidence: 发生率，发病率。of dementia has fallen by around a f ifth in the past 20 years, partly because of giving up smoking. It is widely assumed that productivity declines after 50, but the average age of founders of the highest-growth US start-ups8. start-up: 创业公司。is now 47.

If we are to enjoy this extra time, we need to extend our mental lifespans to match our physical ones. And that means making the most of breakthroughs in neuroscience which show that our brains keep learning and adapting throughout our lives. Brandnew neurons have been found even in the brains of 70-year-olds w ith terminal cancer.9. brand-new: 全新的；neuron: 神经元；terminal: 晚期的。People have recovered from strokes, despite permanently damaging whole areas of their brains, because other areas have stepped in, like airline passengers seizing the controls from an unconscious pilot.10. 虽然中风会对大脑造成整体上的永久性损伤，但人们之所以能够康复，是因为大脑其他区域的介入，就好像当飞行员陷入昏迷时，飞机上的乘客开始进行操作指挥一样。stroke: 中风。Scientists are f inding new ways to help people w ith psychiatric disorders overcome their conditions, by calming down certain circuits in the brain and rewiring others.11. psychiatric disorder: 精神疾病，精神紊乱；circuit: 回路。

It all started w ith the humble canary12. canary: 金丝雀。. Unlike other songbirds, w hich churn out the same old tunes, canaries are the hit record producers of the avian world,13. churn out: 粗制滥造出；hit record: 畅销唱片，此处用作比喻义；avian: 鸟的。creating new melodies every year to attract a mate. On examining their brains, scientists discovered that they generate new brain cells or neurons each spring, almost doubling their brains in size. Later, it w as discovered that humans also generate new neurons. We do this in the hippocampus, which lies deep under the cerebral cortex, learning and consolidating new information.14. hippocampus: 海马体；cerebral cortex: 大脑皮质；consolidate: 巩固。

A big question has been how to put the new brain cells w e create to lasting good use, by incorporating15. incorporate: 吸收，纳入。them deep into mental circuits. Experiments with mice suggest three things help: aerobic exercise16. aerobic exercise: 有氧运动。, social contact and new challenges. Eighteen-monthold mice, the equivalent of 65-year-old humans, have developed f ive times the number of new neurons as fellow rodents17. rodent: 啮齿动物。w hen given wheels to run on, tunnels to explore, and other mice to make friends with. They also learn to navigate mazes more prof iciently than those raised in duller conditions.18. maze: 迷宫；prof iciently: 熟练地。

Human brains benef it from aerobic exercise too. One group of older people who participated in an aerobic f itness programme for three months were found to have signif icantly increased their brain volume, unlike another group who did stretching and toning19. tone: 使（皮肤、肌肉等）更强健，使更健康。—perhaps because aerobic exercise increases the blood supply and oxygen to the hippocampus. Moreover, exercise is increasingly recognised as protective against dementia.

Just as we get physically f itter, and so can endure longer workouts, so the neurons in our brains start to f ire faster, and more in sync with20. in sync with: 与……同步。each other, when we repeatedly focus intensely on learning a new skill. Neurons which “f ire together, wire together”: They give out clearer signals. This is important, because clearer signals improve memory.

One reason we forget things as we get older, scientists believe, is that our brains are increasingly struggling through “noise”: fuzzy21. fuzzy: 不清楚的，不清晰的。signals given out by neurons which are not syncing properly. We process new events more slowly as we get older, which makes it harder to form a clear memory of someone's name, or who said what at the party.

Many scientists are trying to f ind w ays to reduce the “noise” in our brains as w e age. One w ay is challenging ourselves in w ays which require our full attention. There has been research into the effects of playing a musical instrument. Musicians who practise regularly and intensively have been found to have more grey matter in part of their frontal lobe, and less age-related degeneration in other parts of the brain,22. grey matter:（中枢神经系统）灰质；frontal lobe: 额叶；degeneration: 退化。than non-musicians.

“You're never too old to learn,” says Dr Lara Boyd, a brain researcher at the University of British Columbia who works with stroke patients. “There's no drug you can take—the primary driver of neuroplastic change in your brain is your ow n behaviour.23. driver: 推动力，内驱力； neuroplastic: 神经可塑的。But the dose needed to learn new skills, or relearn old ones, is very large.”

Slumping into24. slump into: 跌入，陷入。a comfortable middle-age may be tempting. But once w e appreciate the enormous potential of our brains, it is clear that w e should be avoiding the ruts25and doing regular mental heavy lifting: through physical exercise, social contact and new challenges.