英語故事:人類的潛意識到底有多強?
【英文原文】
Picking our brains: How powerful is the subconscious?
SUBCONSCIOUS thought is the brain's dumb autopilot - the chump behind repetitive tasks, Freudian slips and all the other things we do "without thinking". That was certainly the prevailing view in the 20th century, but the subconscious has lately gone up in the world. It takes centre stage in creativity, puts the "eureka!" into problem-solving, plays a crucial role in learning and memory, and it's even better at making tough decisions than rational analysis is (New Scientist, 1 December 2007, p 42).
It was in the 1980s that the late neuroscientist Benjamin Libet saw a spark of brain activity 300 milliseconds before subjects consciously chose to twitch a finger. We now know the unconscious decision happens even earlier. In 2008, John-Dylan Haynes at the Bernstein Center for Computational Neuroscience in Berlin, Germany, found brain activity up to 10 seconds before a conscious decision to move (Nature Neuroscience, vol 11, p 543).
Stanislas Dehaene, director of the Cognitive Neuroimaging Unit at INSERM, France, has elegantly revealed the subtle interplay between subconscious and conscious thought. In his experiment, volunteers saw a word flashed onto a screen, followed almost immediately by a picture, which masks conscious perception of the word. As the time interval between the two increases, the word suddenly pops into consciousness - accompanied by characteristic activity on a brain scan. This usually happened when the interval reached around 50 milliseconds, but when emotional words such as "love" or "fear" were used, it happened a few milliseconds earlier. It is as though the decision about the word's importance and attention-worthiness was taken by the subconscious itself (PLoS Biology, vol 5, e260).
Experiments like these have changed our views about the relationship between conscious and subconscious thought, putting the latter firmly in charge. Think of consciousness as a spotlight, with the subconscious controlling when to turn it on and where to direct the beam. "The conscious mind is not free," says Haynes. What we think of as "free will" is actually found in the subconscious.
【中文譯文】
潛意識思維是大腦的傻瓜式自動控制儀.無數次重複工作之後的本能反應，弗洛伊德口誤（無意識的說錯話），還有其它不經思考就做的所有事情，這些就是20世紀人們對潛意識的普遍看法.最近世界上對潛意識又有了新的認識。潛意識被認爲是創造力的中心舞臺，能夠忽然爆發靈感解決問題，在學習和記憶中扮演着重要的角色，它甚至
在做艱難決定的時候表現比在理性分析時更出色。
已故的神經學家本傑明利貝特在上世紀80年代發現一個現象，受試者在下意識選擇彎曲一個手指之前300毫秒大腦就會有短暫的活動。我們現在知道無意識的決定甚至發生的更早。2008年，德國柏林伯恩斯坦神經系統計算科學中心的約翰迪倫海恩斯發現在有意識的決定做出之前多達10秒就會有大腦活動會出現。
法國INSERM的認知神經影像學組主任斯坦尼斯德阿納已經完美的揭示出潛意識和意識思維之間微妙的關係。在他的實驗中，讓志願者觀察屏幕上快速閃過的單詞，緊接着用一幅圖片覆蓋前面的單詞，用來掩蓋前面單詞產生的意識知覺。當單詞和圖片之間的間隔時間增加時，志願者會開始對單詞產生意識知覺，同時伴隨一個典型的大腦活動。這通常發生在間隔時間達到50毫秒左右時，但是當用到表示情緒的詞彙時，例如“愛”“恐懼”，這個時間會更加提前幾毫秒，好像單詞的重要性和值得注意是由潛意識自己決定的一樣。
類似這種實驗已經改變了我們對於意識和潛意識思維之間關係的看法，對後者所起的作用有更深刻的認識。如果把意識知覺當做一個聚光燈，那麼潛意識就是它控制裝置，決定燈光什麼時候打開，把光束指向哪裏。“意識思維不是自由的。”哈恩斯說。我們所認爲的“自由意志”實際上是建立在潛意識的基礎之上的。
