經顱電刺激術 有助於人們學習數學概念大綱

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.
在牛津大學(Oxford University)實驗心理學系的一個實驗室裏，研究人員羅伊・科恩・卡多什(Roi Cohen Kadosh)正在試驗一項有趣的治療方法：他讓低劑量的電流流經成年人和最小年齡爲八歲的兒童的大腦，讓他們更會做數學題。

A relatively new brain-stimulation technique called transcranial electrical stimulation may help people learn and improve their understanding of math concepts.
相對較新的大腦刺激技術“經顱電刺激術”（transcranial electrical stimulation，簡稱tES）可能有助於人們學習數學概念，並提高他們對數學概念的理解。

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.
電極被放在一頂很緊的帽子裏，戴在頭上把頭包住。這款設備採用一顆常常用於煙霧探測器的九伏電池，只會產生微小的電流，可以瞄準大腦的特定區域，也可以應用於整個大腦。微弱的電流降低了副作用風險，從而開啓了將它用作普通認知促進器、甚至用於沒有認知障礙的人的可能性。科學家也在探索其治療情緒障礙和其他狀況的用途。

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・卡多什博士在學習促進和大腦刺激方面所做的開創性工作，從一個側面反映了研究大腦刺激和認知刺激技術的科學家面臨的漫長征程。和圈內其他研究人員一樣，他曾面臨公衆對於安全性和副作用的擔憂，也曾面臨其他科學家關於上述發現在更廣泛人羣中是否成立的疑慮。

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?
這項技術也存在倫理問題。如果它真的能夠增強人的認知表現，是不是應該讓任何買得起的人都可以買到那款在美國已經有售的設備？是否應該讓父母可以在沒有監控的情況下爲他們的孩子實施這樣的刺激？

'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・卡多什博士說：“研究還處於初步階段，但一些公司已經在銷售這種設備，把它當成一種學習工具來推銷。務必要非常小心。”

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.'
用電流治療多種腦部疾病的概念經歷了一段漫長而又艱難的歷史。其中最值得一提的，恐怕要數1938年開發出來用於治療嚴重精神疾病的“電休克療法”。在《飛越瘋人院》(One Flew over the Cuckoo's Nest)等電影裏面，它常常被刻畫成一種把人弄成殭屍模樣的中世紀療法。

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.
這麼多年以來，電休克療法已經大幅進步，被認爲適合用於某些對其他療法不起反應的重性抑鬱症，以及其他相關的嚴重情緒狀態。

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.
一些新的大腦刺激技術也已經開發出來，比如對大腦發揮起博器作用的深部腦刺激術(deep brain stimulation，簡稱DBS)。深部腦刺激術是把電極植入大腦，並依靠胸腔裏的電池組持續刺激神經元。深部腦刺激術設備用於治療帕金森氏症的震顫已經獲得美國監管機構的批准，治療慢性疼痛和強迫症的可行性也在繼續得到研究。

Transcranial electrical stimulation, or tES, is one of the newest brain stimulation techniques. Unlike DBS, it is noninvasive.
經顱電刺激術是最新的大腦刺激技術之一。和深部腦刺激術不同，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・卡多什博士說，如果經顱電刺激術繼續展現出成功的希望，那麼“這樣一種療法可能就有機會成爲21世紀的新藥”。

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.
現年37歲、育有兩個孩子的科恩・卡多什在以色列本-古裏安大學(Ben-Gurion University)讀完研究生之後到倫敦大學學院(University College London)做博士後研究，師從文森特・沃爾什(Vincent Walsh)。現在，這位牛津大學高級研究員坐在一間狹小而整潔的辦公室裏，對大腦刺激及其幫助數學不好的孩子的潛力表達了謹慎的熱情。辦公室的架子上放着一個大腦模型。

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.
據估計，多達6%的人患有一種名叫“發展性計算障礙”(developmental dyscalculia)的數學學習缺陷。它跟閱讀障礙(dyslexia)相似，只不過有問題的是數字而不是文字。另外還有很多人表示他們覺得數學很難。患有發展性計算障礙的人執行一些日常任務也可能存在困難，比如電話號碼的記憶、賬單的理解等。

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.
經顱電刺激術是否能夠成爲一種有用的認知促進方法，仍然有待觀察。科恩・卡多什博士最初是在以色列上大學時想到了這種可能性。當時他用經顱磁刺激術(transcranial magnetic stimulation)做了一次實驗（經顱磁刺激術採用磁性線圈來形成更強大的電流。）

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.
他發現，他可以短暫關閉一些已知對認知技能有着重要作用的腦部區域。利用經顱磁刺激術刺激大腦頂葉時，他發現平時精通數字的博士生的運算技能降低到了類似於發展性計算障礙患者的水平。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?
於是他繼續發問：如果說電流可以關掉大腦的某些區域、讓人暫時出現運算困難，那麼另外某種刺激是否可以提高數學成績？

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.
對於某些數學不行的人來講，認知訓練在一定程度上是有用的。科恩・卡多什博士猜想，如果在認知訓練的同時刺激大腦，其效果有沒有可能提高？

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.
但經顱磁刺激術不是合適的工具，因爲它所導入的電流太強。科恩・卡多什博士苦尋合適的刺激種類，直到一位曾經與德國研究人員合作的同事回來跟他說起了經顱電刺激術。在當時，這還是一項新技術。科恩・卡多什博士決定採用經顱電刺激術。

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.
從那時起，他的小組開展了一系列的研究，發現在不存在數學困難的成年人身上，經顱電刺激似乎有助於提高他們執行多種數學任務的學習速度。現在他們在存在數學困難的人身上也看到了初步證據。

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.
參與者通常是一星期內每天前來參加爲時30分鐘的刺激與訓練課程。科恩・卡多什博士的團隊已經開始研究八歲到10歲的兒童，他們在一個月內每星期接受兩次訓練與刺激。包括科恩・卡多什博士的研究在內，經顱電刺激術研究的參與者往往都是十幾個，所以其他研究人員對研究結果的重複是很重要的。

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.
在一間暖和舒適的小房間裏，參與者（常常是牛津的學生）坐在一塊電腦屏幕前，完成數百次測試。在這些測試中，他們學會將數值同抽象的非數字符號掛鉤，猜想哪些符號“大於”其他符號，就像人們學會三大於二的過程一樣。

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.
神經元在觸發時傳遞信息，這能夠促成學習的過程。研究已經表明，經顱電刺激似乎是通過降低神經元觸發閾值來發揮作用的。除此以外，這種刺激似乎還會引起學習、記憶所涉神經化學物質發生變化。

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.
但目前爲止的實驗結果在不同的人身上似乎存在着顯著差異。科學家已經知道，刺激大腦的區域不對或電流過高、過久，都會對學習過程產生抑制效應。科恩・卡多什博士舉例說，年輕人和老年人對同一區域相同電流的反應剛好是相反的。

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《人類神經科學前沿》(Frontiers in Human Neuroscience)雜誌發表了一篇論文。在論文中，他們指出一名發展性計算障礙患者成績大有長進，而另一名研究對象卻沒有。

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.
已經明確的是，任何人要嘗試這種療法，不僅需要刺激大腦，同時也需要訓練大腦。科恩・卡多什博士說，要不然“就像坐在沙發上吃增肌粉”。

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・卡多什博士和實驗室研究生貝婭特麗克絲・克勞斯(Beatrix Krause)一直在測量個體的反應差異。研究已經發現，房間昏暗還是明亮，實驗對象抽不抽菸，甚至女性是否處於月經期間，都有可能影響大腦對電刺激的反應。

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・卡多什博士實驗室和其他實驗室的研究結果已經表明，即使刺激停止，那些從中受益的人仍將維持高於未受刺激者的成績水平，最久維持到一年之後。如果後來沒有訓練，那麼所有人的成績都會隨着時間的推移而下降，但受刺激組的成績依然好於未受刺激組。科恩・卡多什博士說，至於重新實施刺激是否會再次改善學習，則仍然有待研究。