经颅电刺激术 有助于人们学习数学概念

In a lab in Oxford University's experimental psychology department, researcher Roi Cohen Kadosh is testing an intriguing treatment: He is sending low-dose electric current through the brains of adults and children as young as 8 to make them better at math.

在牛津大学(Oxford University)实验心理学系的一个实验室里，研究人员罗伊・科恩・卡多什(Roi Cohen Kadosh)正在试验一项有趣的治疗方法：他让低剂量的电流流经成年人和最小年龄为八岁的儿童的大脑，让他们更会做数学题。

A relatively new brain-stimulation technique called transcranial electrical stimulation may help People learn and improve their understanding of math concepts.

相对较新的大脑刺激技术“经颅电刺激术”（transcranial electrical stimulation，简称tES）可能有助于人们学习数学概念，并提高他们对数学概念的理解。

The electrodes are placed in a tightly fitted cap and worn around the head. The device, run off a 9-volt battery commonly used in smoke detectors, induces only a gentle current and can be targeted to specific areas of the brain or applied generally. The mild current reduces the risk of side effects, which has opened up possibilities about using it, even in individuals without a disorder, as a general cognitive enhancer. Scientists also are investigating its use to treat mood disorders and other conditions.

电极被放在一顶很紧的帽子里，戴在头上把头包住。这款设备采用一颗常常用于烟雾探测器的九伏电池，只会产生微小的电流，可以瞄准大脑的特定区域，也可以应用于整个大脑。微弱的电流降低了副作用风险，从而开启了将它用作普通认知促进器、甚至用于没有认知障碍的人的可能性。科学家也在探索其治疗情绪障碍和其他状况的用途。

Dr. Cohen Kadosh's pioneering work on learning enhancement and brain stimulation is one example of the long journey faced by scientists studying brain-stimulation and cognitive-stimulation techniques. Like other researchers in the community, he has dealt with public concerns about safety and side effects, plus skepticism from other scientists about whether these findings would hold in the wider population.

科恩・卡多什博士在学习促进和大脑刺激方面所做的开创性工作，从一个侧面反映了研究大脑刺激和认知刺激技术的科学家面临的漫长征程。和圈内其他研究人员一样，他曾面临公众对于安全性和副作用的担忧，也曾面临其他科学家关于上述发现在更广泛人群中是否成立的疑虑。

There are also ethical questions about the technique. If it truly works to enhance cognitive performance, should it be accessible to anyone who can afford to buy the device -- which already is available for sale in the U.S.? Should parents be able to perform such stimulation on their kids without monitoring?

这项技术也存在伦理问题。如果它真的能够增强人的认知表现，是不是应该让任何买得起的人都可以买到那款在美国已经有售的设备？是否应该让父母可以在没有监控的情况下为他们的孩子实施这样的刺激？

'It's early days but that hasn't stopped some companies from selling the device and marketing it as a learning tool,' Dr. Cohen Kadosh says. 'Be very careful.'

科恩・卡多什博士说：“研究还处于初步阶段，但一些公司已经在销售这种设备，把它当成一种学习工具来推销。务必要非常小心。”

The idea of using electric current to treat the brain of various diseases has a long and fraught history, perhaps most notably with what was called electroshock therapy, developed in 1938 to treat severe mental illness and often portrayed as a medieval treatment that rendered people zombielike in movies such as 'One Flew over the Cuckoo's Nest.'

用电流治疗多种脑部疾病的概念经历了一段漫长而又艰难的历史。其中最值得一提的，恐怕要数1938年开发出来用于治疗严重精神疾病的“电休克疗法”。在《飞越疯人院》(One Flew over the Cuckoo's Nest)等电影里面，它常常被刻画成一种把人弄成僵尸模样的中世纪疗法。

Electroconvulsive therapy has improved dramatically over the years and is considered appropriate for use against types of major depression that don't respond to other treatments, as well as other related, severe mood states.

这么多年以来，电休克疗法已经大幅进步，被认为适合用于某些对其他疗法不起反应的重性抑郁症，以及其他相关的严重情绪状态。

A number of new brain-stimulation techniques have been developed, including deep brain stimulation, which acts like a pacemaker for the brain. With DBS, electrodes are implanted into the brain and, though a battery pack in the chest, stimulate neurons continuously. DBS devices have been approved by U.S. regulators to treat tremors in Parkinson's disease and continue to be studied as possible treatments for chronic pain and obsessive-compulsive disorder.

一些新的大脑刺激技术也已经开发出来，比如对大脑发挥起博器作用的深部脑刺激术(deep brain stimulation，简称DBS)。深部脑刺激术是把电极植入大脑，并依靠胸腔里的电池组持续刺激神经元。深部脑刺激术设备用于治疗帕金森氏症的震颤已经获得美国监管机构的批准，治疗慢性疼痛和强迫症的可行性也在继续得到研究。

Transcranial electrical stimulation, or tES, is one of the newest brain stimulation techniques. Unlike DBS, it is noninvasive.

经颅电刺激术是最新的大脑刺激技术之一。和深部脑刺激术不同，它是非侵入性的。

If the technique continues to show promise, 'this type of method may have a chance to be the new drug of the 21st century,' says Dr. Cohen Kadosh.

科恩・卡多什博士说，如果经颅电刺激术继续展现出成功的希望，那么“这样一种疗法可能就有机会成为21世纪的新药”。

The 37-year-old father of two completed graduate school at Ben-Gurion University in Israel before coming to London to do postdoctoral work with Vincent Walsh at University College London. Now, sitting in a small, tidy office with a model brain on a shelf, the senior research fellow at Oxford speaks with cautious enthusiasm about brain stimulation and its potential to help children with math difficulties.

现年37岁、育有两个孩子的科恩・卡多什在以色列本-古里安大学(Ben-Gurion University)读完研究生之后到伦敦大学学院(University College London)做博士后研究，师从文森特・沃尔什(Vincent Walsh)。现在，这位牛津大学高级研究员坐在一间狭小而整洁的办公室里，对大脑刺激及其帮助数学不好的孩子的潜力表达了谨慎的热情。办公室的架子上放着一个大脑模型。

Up to 6% of the population is estimated to have a math-learning disability called developmental dyscalculia, similar to dyslexia but with numerals instead of letters. Many more people say they find math difficult. People with developmental dyscalculia also may have trouble with daily tasks, such as remembering phone numbers and understanding bills.

据估计，多达6%的人患有一种名叫“发展性计算障碍”(developmental dyscalculia)的数学学习缺陷。它跟阅读障碍(dyslexia)相似，只不过有问题的是数字而不是文字。另外还有很多人表示他们觉得数学很难。患有发展性计算障碍的人执行一些日常任务也可能存在困难，比如电话号码的记忆、账单的理解等。

Whether transcranial electrical stimulation proves to be a useful cognitive enhancer remains to be seen. Dr. Cohen Kadosh first thought about the possibility as a university student in Israel, where he conducted an experiment using transcranial magnetic stimulation, a tool that employs magnetic coils to induce a more powerful electrical current.

经颅电刺激术是否能够成为一种有用的认知促进方法，仍然有待观察。科恩・卡多什博士最初是在以色列上大学时想到了这种可能性。当时他用经颅磁刺激术(transcranial magnetic stimulation)做了一次实验（经颅磁刺激术采用磁性线圈来形成更强大的电流。）

He found that he could temporarily turn off regions of the brain known to be important for cognitive skills. When the parietal lobe of the brain was stimulated using that technique, he found that the basic arithmetic skills of doctoral students who were normally very good with numbers were reduced to a level similar to those with developmental dyscalculia.

他发现，他可以短暂关闭一些已知对认知技能有着重要作用的脑部区域。利用经颅磁刺激术刺激大脑顶叶时，他发现平时精通数字的博士生的运算技能降低到了类似于发展性计算障碍患者的水平。

That led to his next inquiry: If current could turn off regions of the brain making people temporarily math-challenged, could a different type of stimulation improve math performance?

于是他继续发问：如果说电流可以关掉大脑的某些区域、让人暂时出现运算困难，那么另外某种刺激是否可以提高数学成绩？

Cognitive training helps to some extent in some individuals with math difficulties. Dr. Cohen Kadosh wondered if such learning could be improved if the brain was stimulated at the same time.

对于某些数学不行的人来讲，认知训练在一定程度上是有用的。科恩・卡多什博士猜想，如果在认知训练的同时刺激大脑，其效果有没有可能提高？

But transcranial magnetic stimulation wasn't the right tool because the current induced was too strong. Dr. Cohen Kadosh puzzled over what type of stimulation would be appropriate until a colleague who had worked with researchers in Germany returned and told him about tES, at the time a new technique. Dr. Cohen Kadosh decided tES was the way to go.

但经颅磁刺激术不是合适的工具，因为它所导入的电流太强。科恩・卡多什博士苦寻合适的刺激种类，直到一位曾经与德国研究人员合作的同事回来跟他说起了经颅电刺激术。在当时，这还是一项新技术。科恩・卡多什博士决定采用经颅电刺激术。

His group has since conducted a series of studies suggesting that tES appears helpful improving learning speed on various math tasks in adults who don't have trouble in math. Now they've found preliminary evidence for those who struggle in math, too.

从那时起，他的小组开展了一系列的研究，发现在不存在数学困难的成年人身上，经颅电刺激似乎有助于提高他们执行多种数学任务的学习速度。现在他们在存在数学困难的人身上也看到了初步证据。

Participants typically come for 30-minute stimulation-and-training sessions daily for a week. His team is now starting to study children between 8 and 10 who receive twice-weekly training and stimulation for a month. Studies of tES, including the ones conducted by Dr. Cohen Kadosh, tend to have a dozen or more participants, so replication of the findings by other researchers is important.

参与者通常是一星期内每天前来参加为时30分钟的刺激与训练课程。科恩・卡多什博士的团队已经开始研究八岁到10岁的儿童，他们在一个月内每星期接受两次训练与刺激。包括科恩・卡多什博士的研究在内，经颅电刺激术研究的参与者往往都是十几个，所以其他研究人员对研究结果的重复是很重要的。

In a small, toasty room, participants, often Oxford students, sit in front of a computer screen and complete hundreds of trials in which they learn to associate numerical values with abstract, nonnumerical symbols, figuring out which symbols are 'greater' than others, in the way that people learn to know that three is greater than two.

在一间暖和舒适的小房间里，参与者（常常是牛津的学生）坐在一块电脑屏幕前，完成数百次测试。在这些测试中，他们学会将数值同抽象的非数字符号挂钩，猜想哪些符号“大于”其他符号，就像人们学会三大于二的过程一样。

When neurons fire, they transfer information, which could facilitate learning. The tES technique appears to work by lowering the threshold neurons need to reach before they fire, studies have shown. In addition, the stimulation appears to cause changes in neurochemicals involved in learning and memory.

神经元在触发时传递信息，这能够促成学习的过程。研究已经表明，经颅电刺激似乎是通过降低神经元触发阈值来发挥作用的。除此以外，这种刺激似乎还会引起学习、记忆所涉神经化学物质发生变化。

However, the results so far in the field appear to differ significantly by individual. Stimulating the wrong brain region or at too high or long a current has been known to show an inhibiting effect on learning. The young and elderly, for instance, respond exactly the opposite way to the same current in the same location, Dr. Cohen Kadosh says.

但目前为止的实验结果在不同的人身上似乎存在着显著差异。科学家已经知道，刺激大脑的区域不对或电流过高、过久，都会对学习过程产生抑制效应。科恩・卡多什博士举例说，年轻人和老年人对同一区域相同电流的反应刚好是相反的。

He and a colleague published a paper in January in the journal Frontiers in Human Neuroscience, in which they found that one individual with developmental dyscalculia improved her performance significantly while the other study subject didn't.

他和一位同事在1月份的《人类神经科学前沿》(Frontiers in Human Neuroscience)杂志发表了一篇论文。在论文中，他们指出一名发展性计算障碍患者成绩大有长进，而另一名研究对象却没有。

What is clear is that anyone trying the treatment would need to train as well as to stimulate the brain. Otherwise 'it's like taking steroids but sitting on a couch,' says Dr. Cohen Kadosh.

已经明确的是，任何人要尝试这种疗法，不仅需要刺激大脑，同时也需要训练大脑。科恩・卡多什博士说，要不然“就像坐在沙发上吃增肌粉”。

Dr. Cohen Kadosh and Beatrix Krause, a graduate student in the lab, have been examining individual differences in response. Whether a room is dark or well-lighted, if a person smokes and even where women are in their menstrual cycle can affect the brain's response to electrical stimulation, studies have found.

科恩・卡多什博士和实验室研究生贝娅特丽克丝・克劳斯(Beatrix Krause)一直在测量个体的反应差异。研究已经发现，房间昏暗还是明亮，实验对象抽不抽烟，甚至女性是否处于月经期间，都有可能影响大脑对电刺激的反应。

Results from his lab and others have shown that even if stimulation is stopped, those who benefited are going to maintain a higher performance level than those who weren't stimulated, up to a year afterward. If there isn't any follow-up training, everyone's performance declines over time, but the stimulated group still performs better than the non-stimulated group. It remains to be seen whether reintroducing stimulation would then improve learning again, Dr. Cohen Kadosh says.

科恩・卡多什博士实验室和其他实验室的研究结果已经表明，即使刺激停止，那些从中受益的人仍将维持高于未受刺激者的成绩水平，最久维持到一年之后。如果后来没有训练，那么所有人的成绩都会随着时间的推移而下降，但受刺激组的成绩依然好于未受刺激组。科恩・卡多什博士说，至于重新实施刺激是否会再次改善学习，则仍然有待研究。