瞭解大腦如何運轉,保證更加健康生活大綱

For the last 20 years neuroscientists have shown us compelling pictures of brain areas 'lighting up' when we see or hear, love or hate, plan or act. These studies were an important first step. But they also suggested a misleadingly simple view of how the brain works. They associated specific mental abilities with specific brain areas, in much the same way that phrenology, in the 19th century, claimed to associate psychological characteristics with skull shapes.

過去20年間，神經學家向人們展示了饒有趣味的畫面：當我們在聆聽或觀賞、喜愛或厭惡、思考或行動時，大腦的不同區域是如何被激活的。是這些研究成果邁出了關鍵性的第一步，但它們對大腦簡單運轉方式的認知卻充滿了誤導。這些研究認爲特定腦部區域和不同心理活動相關，這一觀點與19世紀的顱相學頗爲相似，此學說宣稱人的心理特質與顱骨形狀相關。

Most people really want to understand the mind, not the brain. Why do we experience and act on the world as we do? Associating a piece of the mind with a piece of the brain does very little to answer that question. After all, for more than a century we have known that our minds are the result of the stuff between our necks and the tops of our heads. Just adding that vision is the result of stuff at the back and that planning is the result of stuff in the front, it doesn't help us understand how vision or planning work.

大多數人更想了解人的心理，而不是頭腦。爲什麼我們對世界產生了現在這樣的感知和行爲？大腦某部分與心理某部分相配合的理論不大能夠回答這個問題。畢竟一個多世紀以來，我們已經認識到，心理活動是源於頸部與頭頂之間的那個器官。單純認爲想象力是大腦後部的產物、規劃能力是大腦前部的產物並不能幫助我們理解想象力或者規劃能力是怎樣運轉的。

But new techniques are letting researchers look at the activity of the whole brain at once. What emerges is very different from the phrenological view. In fact, most brain areas multitask; they are involved in many different kinds of experiences and actions. And the brain is dynamic. It can respond differently to the same events in different times and circumstances.

但是新技術使研究者得以同時觀測整個大腦的活動，從而得出的結果與顱相學理論大爲不同。事實上，大部分腦部區域都身兼數職，參與了多種多樣的感知和行爲。大腦非常活躍，它能夠在不同的時間和空間對於相同的事件產生不同的反應。

A new study in Nature Neuroscience by Jack L. Gallant, Tolga Çukur and colleagues at the University of California, Berkeley, dramatically illustrates this new view. People in an fMRI scanner watched a half-hour-long sequence combining very short video clips of everyday scenes. The scientists organized the video content into hundreds of categories, describing whether each segment included a plant or a building, a cat or a clock.

加州大學伯克利分校(University of California, Berkeley)的傑克•L•格加倫特(Jack L. Gallant)和托爾加•丘庫爾(Tolga Çukur)及其同事在《自然神經科學》(Nature Neuroscience)雜誌上發表了一項新的研究，很好地詮釋了這一新觀點。實驗對象在覈磁共振儀上觀看了時長半小時的視頻，其中包含了關於日常生活的小片段。科學家將視頻內容歸爲數百個種類，劃分標準是每個片段中是否包含植物或者建築、貓或者時鐘，等等。

Then they divided the whole brain into small sections with a three-dimensional grid and recorded the activity in each section of the grid for each second. They used sophisticated statistical analyses to find the relationship between the patterns of brain activity and the content of the videos.

他們使用3D座標把大腦劃分爲若干小區域，並且記錄下每個區域每秒鐘的活動情況，再採用嚴密的數據分析法來找到腦部活動機制和視頻內容之間的關係。

The twist was that the participants either looked for human beings in the videos or looked for vehicles. When they looked for humans, great swaths of the brain became a 'human detector'─more sensitive to humans and less sensitive to vehicles. Looking for vehicles turned more of the brain into a 'vehicle detector.' And when people looked for humans their brains also became more sensitive to related objects, like cats and plants. When they looked for vehicles, their brains became more sensitive to clocks and buildings as well.

實驗參與者被要求在影片中尋找人物或者交通工具。尋找人物的時候，腦部的若干區域會變爲一臺“人物探測器”，也就是對於人物更加敏感而對交通工具較不敏感。尋找交通工具則使腦部更像一臺“交通工具探測器”。當人們在搜尋人物時，大腦也對相關的事物更爲敏感，比如貓咪和植物。而搜尋交通工具時，大腦則對鐘錶和建築物更爲敏感。

In fact, the response patterns of most brain areas changed when people changed the focus of their attention. Something as ineffable as where you focus your attention can make your whole brain work differently.

事實上，大多數腦部區域的反應機制隨着人們注意力的轉移而改變。人的注意力集中在不同地方，整個大腦的運行方式也就不同。

People often assume that knowing about the brain is all that you need to explain how the mind works, so that neuroscience will replace psychology. That may account for the curious popular enthusiasm for the phrenological 'lighting up' studies. It is as if the very thought that something psychological is 'in the brain' gives us a little explanatory frisson, even though we have known for at least a century that everything psychological is 'in the brain' in some sense. But it would be just as accurate to say that knowing about the mind explains how the brain works.

人們常常理所當然地認爲了解了大腦就能夠解釋心理活動，所以神經學將會取代心理學。這一點可以解釋人們對於顱相學“激活”理論的好奇和熱情。儘管從某種程度上來說，人們早在一個多世紀前就已經瞭解到所有心理活動都“存在於腦海裏”，但這一說法仍舊無法解釋清楚問題。而較爲準確的說法是，瞭解了心理就能解釋大腦如何運轉。

The new, more dynamic picture of the brain makes psychology even more crucial. The researchers could only explain the very complex pattern of brain activity by relating it to what they knew about categorization and attention. In the same way, knowing the activity of every wire on every chip in my computer wouldn't tell me much if I didn't also know the program my machine was running.

這些新的、更富於動態的腦部圖片令心理學變得更加重要，因爲神經學研究者只能通過控制分類方法和關注點來解釋複雜的腦部活動機制。這就好比，如果不知道電腦軟件的運行方式，即便知道電腦硬件的每根導線如何工作也並無大用。

Neuroscience may be sexier than psychology right now, and it certainly has a lot more money and celebrity. But they really cannot get along without each other.

或許當下神經學比心理學更受關注，獲得了更多經費也產生了更多名家，但是這兩門學科是相互依存的。