脑科学证明:活到老,学到老

“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.

“人脑可塑性”不止是一个时髦话——大脑确确实实能成长，能改变，不过，这个概念很容易和小孩子的适应能力联系起来，对于他们而言，世界总是那么新鲜，不想大人，已经习惯了。那么，大脑能能变多少呢?很多，就如一份新研究报告里所言，只要六个月，学习阅读，就能让一个从未阅读的成年人大脑发生巨变。

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.

一群认知科学家想知道一个人的文化生活能多大程度上影响人的大脑，所以他们就开始研究对于从未读过书的人来说，学会阅读，对大脑的影响能有多大。

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位来自Lucknow的印度人合作，他们平均年龄31岁，说印地语，全部来自山村。参与研究的对象，全都没有上过学，没有读写能力。在一开始学习的时候，他们没有人能读超过8个单词。

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个人开始学习读书写字，另外9个什么都不干。读书组的由一位专业导师指导学习，学习6个月。学习之后，他们的大脑发生了惊天巨变。

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.

为了追踪这些变化，团队用磁共振仪器扫描他们的大脑，再检查一遍对比组的大脑。学会读书的人改变的不仅仅是大脑皮质( cerebral cortex)和脑灰质(gray matter)，虽然这些是公认的大脑学习中枢。改变的地方还有控制肢体的脑干，还有控制感觉输入的丘脑( 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.

团队认为这些变化可以被阅读技能的熟练解释，因为，阅读的时候，眼睛会用特定的方式看文本，这一点已经被此前针对读写困难小孩的研究证明了，那项研究中，研究人员花通过12小时的电视游戏提升了他们的视觉注意力，结果他们的阅读能力有显著提升。脑干和丘脑就和人的注意力有关。

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.

这项最新的研究能改变科学家对读写困难症的看法。此前的研究只是表面，发现丘脑的结构与功能和读写困难有关，这个新结论能表明，学会读书，能改变丘脑和其他脑内部分的连接方式，这一点能帮助科学家弄明白，切断这些连接会不会导致读写困难症。

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.

这个研究也有一些缺陷，由这一群小小的样本得出的结论能不能适用于所有人还有待进一步研究。而且，这些人是既学习读书也学习写字，还不知道，读和写那一个对人脑影响更大。研究人员还表示，老师使用的是”当地的阅读教学方式，“这导致这项研究无法复制到其他的地方。

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.

科学家早就已经知道，学习阅读会让小孩的大脑发生改变。对成年人也能得出同样的结论，他们并不惊讶。但是对于广大成年人来说，这种变化的幅度能激励我们我们：无论你多大年纪，读书都会让你的大脑有变化。