腦科學證明:活到老,學到老

“Neuroplasticity” is more than a buzzword—it’s the brain’s ability to grow, and change. But it’s easy to associate this adaptiveness with kids, for whom the entire world is new, rather than adults, who have already seen it all. Just how much can the adult brain change? A lot, suggests a new study. As New Scientist’s Anil Ananthaswamy reports, it took just six months to make significant impacts on the brains of adults who learned to read for the first time.

“人腦可塑性”不止是一個時髦話——大腦確確實實能成長，能改變，不過，這個概念很容易和小孩子的適應能力聯(lián)系起來，對于他們而言，世界總是那么新鮮，不想大人，已經(jīng)習慣了。那么，大腦能能變多少呢?很多，就如一份新研究報告里所言，只要六個月，學習閱讀，就能讓一個從未閱讀的成年人大腦發(fā)生巨變。

A group of cognitive scientists wondered how cultural experiences—ones that influence people’s lives, but not necessarily their genes—affect the human brain. So they honed in on how reading affects the brain in adults who never learned how.

一群認知科學家想知道一個人的文化生活能多大程度上影響人的大腦，所以他們就開始研究對于從未讀過書的人來說，學會閱讀，對大腦的影響能有多大。

The researchers worked with 30 Hindi-speaking adults—about 31 years old on average—from villages near the Indian city of Lucknow. Every participant in the study could not read or write and never attended school. None of them could read more than eight words when the study began.

研究者和30位來自Lucknow的印度人合作，他們平均年齡31歲，說印地語，全部來自山村。參與研究的對象，全都沒有上過學，沒有讀寫能力。在一開始學習的時候，他們沒有人能讀超過8個單詞。

Twenty-one people were taught to read and write while another nine were not. The people assigned to the reading group worked with a professional instructor who taught them for six months. And over this course of time, their brains underwent some amazing transformations.

其中21個人開始學習讀書寫字，另外9個什么都不干。讀書組的由一位專業(yè)導師指導學習，學習6個月。學習之后，他們的大腦發(fā)生了驚天巨變。

To track the changes, the team took brain scans with fMRI machines before and after the experiment while the participants’ brains were at rest. People who did learn to read showed changes not just in their cerebral cortex or gray matter, which is thought to be the brain’s main learning center, but also in other brain areas like the brain stem, which controls reflexes and regulates bodily functions, and the thalamus, which processes sensory input and routes that information elsewhere in the brain.

為了追蹤這些變化，團隊用磁共振儀器掃描他們的大腦，再檢查一遍對比組的大腦。學會讀書的人改變的不僅僅是大腦皮質(zhì)( cerebral cortex)和腦灰質(zhì)(gray matter)，雖然這些是公認的大腦學習中樞。改變的地方還有控制肢體的腦干，還有控制感覺輸入的丘腦( thalamus)。

The team thinks that the changes might be explained by the increased motor skills reading requires—after all, the eyes must be trained to look at the text in a specific way, and a previous study has shown that kids with dyslexia who train for 12 hours using a video game that challenges their visual attentiveness show improvements in reading. Both the brain stem and the thalamus contribute to an individual’s ability to pay attention to different stimuli.

團隊認為這些變化可以被閱讀技能的熟練解釋，因為，閱讀的時候，眼睛會用特定的方式看文本，這一點已經(jīng)被此前針對讀寫困難小孩的研究證明了，那項研究中，研究人員花通過12小時的電視游戲提升了他們的視覺注意力，結果他們的閱讀能力有顯著提升。腦干和丘腦就和人的注意力有關。

This latest study could change the way scientists view dyslexia. Previous studies have shown a connection between the structure and function of the thalamus and dyslexia. These new results suggest that learning to read changes the way the thalamus connects to the rest of the brain, and that in turn could help scientists figure out if disruptions in these connections could cause dyslexia.

這項最新的研究能改變科學家對讀寫困難癥的看法。此前的研究只是表面，發(fā)現(xiàn)丘腦的結構與功能和讀寫困難有關，這個新結論能表明，學會讀書，能改變丘腦和其他腦內(nèi)部分的連接方式，這一點能幫助科學家弄明白，切斷這些連接會不會導致讀寫困難癥。

The study has some downsides, however. It dealt with such a small sample that it’s hard to know if those results might hold for a larger group of people. And since adults learned to both read and write, it’s not clear if one drove brain changes more than the other. Researchers also noted that the teacher used a “locally established method of reading instruction,” which could make the study challenging to replicate in other areas.

這個研究也有一些缺陷，由這一群小小的樣本得出的結論能不能適用于所有人還有待進一步研究。而且，這些人是既學習讀書也學習寫字，還不知道，讀和寫那一個對人腦影響更大。研究人員還表示，老師使用的是”當?shù)氐拈喿x教學方式，“這導致這項研究無法復制到其他的地方。

Scientists already know that when kids learn to read, their brains change. So it’s not that surprising that adults’ brains would, too. But the sheer magnitude of that change for adults who learn to read is a reminder that brains are capable of intense change—no matter how old you are.

科學家早就已經(jīng)知道，學習閱讀會讓小孩的大腦發(fā)生改變。對成年人也能得出同樣的結論，他們并不驚訝。但是對于廣大成年人來說，這種變化的幅度能激勵我們我們：無論你多大年紀，讀書都會讓你的大腦有變化。