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开发老年人大脑潜藏的惊人学习能力

更新时间:2019/10/21 12:24:52 来源:纽约时报中文网 作者:佚名

The amazing fertility of the older mind
开发老年人大脑潜藏的惊人学习能力

If you ever fear that you are already too old to learn a new skill, remember Priscilla Sitienei, a midwife from Ndalat in rural Kenya. Having grown up without free primary school education, she had never learnt to read or write. As she approached her twilight years, however, she wanted to note down her experiences and knowledge to pass down to the next generation. And so, she started to attend lessons at the local school – along with six of her great-great-grandchildren. She was 90 at the time.

如果你担心自己年纪太大,已经没法学会新技能,那不妨想一想来自肯尼亚农村那代拉(Ndalat)的助产士普莉斯拉·希蒂昂妮(Priscilla Sitienei)的经历。她小时候没有免费的小学教育,所以她不会认字,也不会写字。不过,临近暮年的她却想要把她的经验和知识记录下来,留传给下一代人。于是,她在本地的学校开始听课——她有六个同学,是她的曾曾孙子孙女。当时,她已经90岁了。

We are often told that “you can’t teach an old dog new tricks” – that the grizzled adult brain simply can’t absorb as much information as an impressionable young child’s. Many people would assume that you simply couldn’t pick up a complex skill like reading or writing, at the age of 90, after a lifetime of being illiterate.

我们常常听说一句话"老狗学不会新把戏"——意思就是老年人的大脑无法像小孩子一样吸收那么多的信息。在很多人看来,像读书写字这样的复杂技能,90岁高龄的文盲是不可能学会的。

The latest studies from psychology and neuroscience show that these extraordinary achievements need not be the exception. Although you may face some extra difficulties at 30, 50 – or 90 – your brain still has an astonishing ability to learn and master many new skills, whatever your age. And the effort to master a new discipline may be more than repaid in maintaining and enhancing your overall cognitive health.

心理学和神经科学最新的研究表明这些惊人的成就未必是例外情况。虽然30岁、50岁或90岁的人会面对额外的困难,但是他们的大脑仍然有惊人的学习能力,能够学会很多新技能。而且掌握一门新学问的努力还有额外的收获:它能够保持并提高你整体的大脑健康。

Wax tablets

蜡板

But there hasn’t always been such an optimistic view of learning brand new skills from scratch as a grown adult.

长期以来,很少有人对成年人从零开始学习新技能持乐观的看法。

The prevailing, pessimistic, view of the ageing mind can be traced back to the Ancient Greeks. In his treatise De Memoria et Reminiscentia, Aristotle compared human memory to a wax tablet. At birth, the wax is hot and pliable, but as it cools it becomes too tough and brittle to form distinct impressions – and our memory suffers as a result.

认为大脑会老化的普遍的较为悲观的看法可以追溯到古希腊。亚里士多德在他的论文《论记忆》(De Memoria et Reminiscentia)中把人类的记忆力比作一块蜡板。在出生时,蜡很烫,可塑性很强,但是随着它渐渐冷却,就会变得又硬又脆,无法形成鲜明的印象——我们的记忆力就会受到影响。

Millennia later, scientists’ understanding of the brain appeared to echo this view. Neuroscientists even use a word to describe the brain’s adaptability – neuroplasticity – that directly recalls the malleable wax of Aristotle’s “tabula rasa”, and as we age, we were thought to lose much of that plasticity.

一千年后,科学家对大脑的理解似乎呼应了这一观点。神经科学家甚至用"神经可塑性"这个词来描述大脑的适应力,不禁让人联想起亚里士多德具有延展性的蜡板。科学家认为,随着人的衰老,大部分可塑性会一同消失。

Childhood, in particular, was thought to be the “critical period” to make those impressions. By the end of the critical period, the brain’s circuits begin to settle, making it far harder to learn many complex new skills.

科学家认为孩提时代是记忆的关键时期。在关键时期将要结束时,大脑的回路就会开始固定下来,导致学习复杂的新技能的难度大大增加。

Compelling evidence for this theory appeared to come from people learning a second language. Young children brought to a new country seemed to find it far easier to reach fluency than their older siblings or parents, for instance.

这一理论的有力证据似乎来自人学习第二语言。例如,儿童在来到新的国家后,似乎能比自己的兄妹和父母更快达到语言流利的程度。

Yet a closer look at the data paints a somewhat rosier picture. Analysing the census records of immigrants, Ellen Bialystok at York University in Toronto showed that the immigrants fluency appeared to decline very gradually with the age at arrival, rather than a drop off a cliff predicted by a critical period. And that may have been partly due to the fact that the children simply had more opportunities to master the language, with the support of schools and their classmates. Or perhaps children are simply less inhibited and aren’t so scared about making mistakes.

不过,仔细研究数据会发现情况扑朔迷离。多伦多的约克大学(York University)的艾伦·比亚韦斯托克(Ellen Bialystok)通过分析移民的调查数据后发现来到外国的移民的语言流利程度并非在过了关键时期后就急速下滑,而是呈现随着年龄的增长逐步下滑的趋势。部分原因可能是儿童有更多的学习语言的机会,有学校和同学的帮助。或者儿童对犯错并不那么在意和害怕。

Just consider the case of Aleksander Hemon. Originally from Sarajevo in then-Yugoslavia, he found himself stranded in the US on the outbreak of the Bosnian war in 1992 – despite having little command of English. “I had this horrible, pressing need to write because things were happening. I needed to do it the same way I needed to eat, but I just had no language to write in,” he later told the New York Times. And so he set about embracing the language on the streets around him. Within three years, he had published his first piece in an American journal, a path that eventually led to three critically acclaimed novels, two short story collections, a book of autobiographical essays, and a MacArthur Genius Award.

不妨看看亚历山大·埃蒙(Aleksander Hemon)的例子。他原本来自前南斯拉夫的萨拉热窝(Sarajevo)。在1992年波斯尼亚战争爆发后,他被困在美国——尽管他几乎不会讲英语。"因为发生了很多事情,所以我迫不及待的要写作,就像吃饭的需要一样,但是我不会书面语言。"他后来这样告诉《纽约时报》。于是,他开始到街上去,学习身边的语言。在三年内,他就在美国的期刊发表了第一篇文章,后来他写出三部受到好评的小说,两部短篇小说集,一部自传式散文集,并获得了麦克阿瑟天才奖(MacArthur Genius Award)。

Hemon’s profound mastery of expression should have been near impossible if language acquisition had to fall within a critical period for us to achieve true fluency. But his sheer determination and the urgency of the situation fuelled his power to learn.

如果语言学习要达到真正的流利必须在关键时期完成,那么埃蒙就几乎不可能精通英语表达。但是他的决心和情况的紧迫性为他提供了学习的动力。

Admittedly, children may still find it easier to master certain skills, particularly those that revolve around the fine-tuning of our perception. A linguist may struggle to exactly match a native’s accent, while a new musician may never be able to acquire the refined perception of “absolute pitch” shown by stars like Ella Fitzgerald or Jimi Hendrix. But as Hemon shows, you can still be an award-winning novelist without sounding like a native, and many accomplished musicians do not have perfect pitch. Amazing progress is still possible in many different fields, and adults may find that they can make up for some of the deficits with their greater capacity for analysis, self-reflection – and discipline.

诚然,儿童学习技能仍然较为容易,尤其是那些与精细的感知能力有关的技能。语言学家可能很难精确模仿母语者的口音,而初出茅庐的音乐家可能很难掌握艾拉·费兹洁拉(Ella Fitzgerald)或吉米·亨德里克斯(Jimi Hendrix)这样的明星对"绝对音感"的把握。但是,埃蒙的例子说明,不需要口音和母语者一样也可以成为获奖小说家,很多功成名就的音乐家也不具备绝对音感。在很多不同的领域仍然有可能实现惊人的进步。而且成年人还可以通过较强的分析能力、自我反省能力和纪律性弥补一部分劣势。

The scientific literature is now dotted with case studies of older adults performing amazing mnemonic feats, including a septuagenarian who learnt to recite all 10,565 lines of John Milton’s Paradise Lost for public performance. Such extended neuroplasticity also seems to be reflected in more recent studies of the brain’s anatomy, revealing that the adult brain is far more fertile than expected, and more than capable of sprouting the connections necessary for profound learning.

科学文献中现在有一些案例研究发现成年人展现出惊人的记忆术。一位七旬老人背诵了约翰·弥尔顿(John Milton)的《失乐园》(Paradise Lost)全文10,565行,并公开表演。最近对大脑的解剖学研究也反映出这种超长记忆术,揭示出成人大脑的能力远远超出预期,绝不限于建立深奥学问所需的神经联系。

Keeping in shape seems to be particularly important for maintaining that plasticity, as exercise helps to release a flood of neurotransmitters and hormones that are known to promote the growth of new brain cells and synapses.

勤加锻炼似乎对保持大脑的可塑性尤为关键,因为它能够促进神经递质和荷尔蒙的大量分泌,有助于促进新的大脑细胞和突触的生长。

A simple lack of confidence may present the biggest barrier – particularly for older learners, past retirement, who may have already started to fear a more general cognitive decline.

最大的障碍可能是缺乏信心——尤其是年长者和退休人士,他们可能已经开始担心认知能力的整体下滑。

Through a string of recent experiments, Dayna Touron at the University of North Carolina at Greensboro has shown that older adults (60 and over) frequently underestimate the power of their own memories, leading to some bad habits that fail to make the best use of their minds.

位于格林斯伯勒(Greensboro)的北卡罗来纳大学(University of North Carolina)的黛娜·图尔农(Dayna Touron)最近通过一连串的实验发现60岁以上的成年人常常低估自己的记忆能力,养成了一些坏习惯,无法充分发挥大脑的能力。

In one (deliberately tedious) study, Touron’s participants had to compare a reference table of word pairings (like ‘dog’ and ‘table’) with a second list, and then identify which words had not appeared in the original table. The word pairings were not difficult to learn, and by the end most people – of all ages – would have been able recite them. But the older adults – aged 60 and over – were more reluctant to rely on their memory, preferring instead to laboriously cross-reference the two tables, even though it took significantly more time. For some reason, they weren’t confident that they had learnt the pairs accurately – and so took the more cautious, but time-consuming, strategy.

在一项故意设计的冗长的研究中,参与者把一个成对词语(比如"狗"和"桌子")的表格和另一个列表进行对照,找出哪些词没有出现在前面的表格里。成对词语并不难学,到最后,大多数人——所有年龄段——本应该能够背诵出来。但是60岁以上的人比较不愿意依赖自己的记忆,而是喜欢费力的来回对照两个表格,尽管这样做浪费很多时间。出于某种原因,他们没有自信能够准确记忆这些成对词语,所以采取了较为谨慎而费时的策略。

In another experiment, the participants had to work through a list of calculations, with many of the sums appearing repeatedly through the list. The younger participants soon started to recall their previous answers, while the older subjects instead decided to perform the calculations from scratch each time.  Again, this did not seem to reflect an actual hole in their memory – many could remember their answers, if they had to, but had simply chosen not to. “We do see some adults who come into the lab and who never shift to using their memory,” says Touron. “They say they know the information, they just prefer not to rely on it.”

在另一项研究中,参与者进行一连串的计算,很多总数反复出现。年纪较小的参与者很快开始回忆做过的答案,而年纪较大的参与者每次都从头开始计算。这也不能说明后者的记忆存在问题——很多人都能够记住自己的答案,只是他们选择不去记忆。"我们确实发现来到实验室的一些成年人从不转换思路,利用自己的记忆。"图尔农说,"他们说自己知道这个信息,他们只是偏向于不依赖它。"

By asking her participants to keep detailed diaries of their routine, Touron has shown this habit of “memory avoidance” may limit their cognitive performance in many everyday activities. Older people may be more likely to rely on GPS when driving, for instance – even if they remember the route – or they may follow a recipe line by line, rather than attempting to recall the steps.

图尔农要求被试者详细记录自己的日常生活,发现这种"回避记忆"的习惯可能会限制他们在很多日常活动中的认知表现。例如,年纪较大的人在开车时更有可能依赖于GPS,即使他们记得路线——或者他们可能会按照菜谱逐行来做菜,而不是尝试记住所有的步骤。

Eventually, that lack of confidence may become a self-fulfilling prophecy – as your memory skills slowly decline through lack of use. On the plus side, she has found that simply giving the older adults feedback on their performance – and underlining the accuracy of their memory – can encourage them to rely more on their recall. “I think it does offer an optimistic picture,” she says.

最后,缺乏信心可能会成为一种自证预言——因为缺乏使用,你的记忆能力就逐渐衰退了。图尔农发现的积极的一面是对年纪较大的成年人给出反馈——并强调他们记忆的准确性——有助于他们更多的依赖自己的回忆。"我觉得这提供了一个乐观的方向。"她说。

Break through those psychological barriers to learning, and you may soon see some widespread and profound benefits, including a sharper mind overall. As evidence, Touron points to research by Denise Park at the Center for Vital Longevity at the University of Texas at Dallas.

只要打破这些心理障碍,你就可能很快发现影响深远的益处,头脑整体都变聪明了。图尔农指出,一个证据是位于达拉斯的得克萨斯大学(University of Texas)的"活力老年中心"(Center for Vital Longevity)的丹尼斯·帕克(Denise Park)进行的研究。

Park first divided her 200 participants into groups and assigned them to a programme of different activities for 15 hours a week for three months. Some were offered the opportunity to learn new skills – quilting, digital photography, or both – that would challenge their long-term memory and attention as they followed complex instructions. Others were given more passive tasks, such as listening to classical music or completing crossword puzzles, or social activities – such as field trips to local sites of interest. At the beginning and the end of the three months, Parks also gave the participants a memory test.

帕克首先把200名参与者分为多个小组,并为他们布置了一系列的不同活动,要求在三个月内完成,每周进行15小时。一些人获得了学习新技能的机会——缝纫、数码摄影,或者两个一起学——依循复杂的指令将挑战他们的长时记忆和注意力。另外一些人拿到了比较被动的任务,比如听古典音乐,完成填词游戏,或者进行社交活动——比如去本地的景点游玩。在这三个月的开始和结尾,帕克对参与者各进行一次记忆力测验。

Of all the participants, only the subjects learning the quilting or the photography enjoyed a significant improvement – with 76% of the photographers showing a higher score at the second memory test, for instance. A later brain scan found that this seemed to be reflected in lasting changes to circuits in the medial frontal, lateral temporal, and parietal cortex - areas associated with attention and concentration. Overall, the more active pastime of learning a new skill led to the more efficient brain activity you might observe in a younger brain, while the passive activities like listening to music brought no changes. Crucially, these benefits were long-lasting, lingering for more than a year after the participants had completed their course.

在所有的参与者中,只有学习缝纫或数码摄影的人出现了大幅度的提高——比如学习摄影的人第二次测验分数提高的占76%。在随后的大脑扫描中,帕克发现这也反映在脑回路的持久改变,比如额中回、侧颞叶和顶叶皮质,这些区域都和注意力和专注力有关。整体来说,学习新技能越是活跃,大脑活动就越是有效率,就像年轻人大脑的情况一样。而听音乐这样的被动活动可能不会带来变化。关键在于,这些益处的影响是持久的,在参与者完成学习后可维持一年以上。

Park emphasises that she still needs to replicate the study with other groups of participants. But if the results are consistent with her earlier findings, then the brain boost of taking up a new hobby may trump so-called “brain training” computer games and apps, with study after study finding that these programs fail to bring about meaningful benefits in real life.

帕克强调她仍然需要通过其他被试者群体来重复实验。但是,如果实验结果与之前的结果一致,那就说明学习新的爱好对脑力的提升有可能会打败所谓能够"锻炼大脑"的电脑游戏和应用。很多研究发现,这些程序无法在实际生活中给人带来有意义的益处。

Although the specific activities that Park chose – photography or quilting – may not appeal to everyone, she suspects the same benefits could emerge from many other hobbies. The essential point is to choose something that is unfamiliar, and which requires prolonged and active mental engagement as you cultivate a new set of behaviours. “it’s important that the task is novel and that it challenges you personally,” Park says. If you are a pianist, you might find greater benefits from learning a language say, than attempting to pick up the organ; if you are a painter, you might take up a sport like tennis.

尽管帕克选择的特定活动——摄影或缝纫——可能不是对所有人都有吸引力,但是她猜测很多其他的爱好也会产生相同的益处。关键点是选择做你不熟悉的并且需要大脑长时间保持活跃参与的事情,培养新的行为模式。"重点是这项任务是新鲜的,对你个人有一定挑战。"帕克说。如果你是钢琴家,学习语言可能会比学管风琴给你带来更大的益处。如果你是画家,你或许可以学习打网球或其他体育运动。

You may be surprised by how much you enjoy the challenge itself. “The participants got more confidence in themselves,” Park says. One man went on to take photographs for his local newspaper; another woman had at first reluctantly attended the quilting class, despite having no real interest in the skill. She still wasn’t convinced by the end, but her successes had nevertheless inspired her to take up a new hobby – painting – instead. “I didn’t like quilting, but I had learnt how to learn,” she told Park.

你可能会惊奇的发现自己享受挑战本身。"参与者的自信心增强了,"帕克说。一个人还去给本地报纸摄影。一名女士一开始不愿意参加缝纫课。虽然她对缝纫没有兴趣,但是最后她自己都不相信自己会获得成功。不过,她由此得到灵感,有了一个新的爱好——绘画。"我不喜欢缝纫,但是我学会了如何去学习。"她对帕克说。

So why not give it a go yourself and attempt to stretch your mind beyond its comfort zone? As Priscilla Sitienei – the 90-year-old Kenyan great-great-grandmother – put it: “Education has no age limit.”

那么,为什么不给自己一次尝试的机会,让大脑走出舒适区?正如肯尼亚90岁的曾曾祖母普莉斯拉·希蒂昂妮所说的:"教育没有年龄上的限制。"

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