下面的原文是Joy在上星期六提到的一個實驗。日本科學家成功將腦活動轉譯成視覺圖像。
實驗者對六名受試者以一張12秒的速率播放400張黑百圖片，並同時記錄腦部活動。這些黑白圖片與腦造影經過程式分析後找到腦活動與外來視覺刺激的關連(correlation)。接下來實驗者令受試者看一組不在那400組之中的黑白圖片，內有neuron文字，透過分析受試者的腦造影，科學家們成功重現受試者們看到的黑白影像。
科學家Kang Cheng在下文中樂觀地表示，十年內，以此科技和其進展的速度，科學應可以在以腦活動判讀thoughts上達到一定的準確度。
Cheng這麼樂觀有兩個可能：一，他認為思想也是圖像，可以用同一組編譯碼解譯；二，即使思想不是圖像，把400組圖像代換成400個概念，電腦還是可以計算出各別概念與腦活動之間的關連，進而破解人心中的想法。前者太過天真，我Cheng應該沒這麼簡單；後者即使不是不可能，我認為還有很多問題，比方說：如何induce受試者想一個特定的概念，並篩濾出只關於此概念的腦活動？或者，我們如何確定受試者的確正在想實驗者要他想的概念？思考很多時候牽涉抽象概念，比方說邏輯關係。我們在處理邏輯關係時速度再慢也不會慢到以秒計。腦造影技術若一直以代謝為腦活動指標，只怕永遠讀不到這些細微活動。還有個關鍵的問題是，如果腦並不是以分區分工的方式處理個別概念，而是多區同時的方式，以目前篩濾腦活動成像的減法技術，篩出來的腦造影根本沒有意義。
最後，在應用上，要讀一個人的心理內容，必須先讓電腦分析他的腦活動與相關刺激的關連。每個人的腦處理資訊的方式就像他的指紋一樣，都是獨特的。受試者都是拿了錢自願讓科學家看他的腦。要是科學家真的能夠解譯人腦了，有誰願意進核磁共振機讓人看他的腦，就像讓人看他的日記一樣？有人也許認為這可以作為刑事偵查的工具，讓把每個嫌疑犯都抓進共振機掃一掃，看看他有沒有犯罪。試問，這難道沒有侵害了疑犯的人權嗎？再者，我要是疑犯中真的有犯罪的那個人，我一定會在編碼的過程中惡搞，讓科學家掃不出任何有意義的資料。腦造影讀心術已經變成科學家的吸金術，但這些技術即使成功，能應用的範圍卻令人質疑，倒不如把資金拿去研究coma的病人，找到如何叫醒他們的方法。
ATR mind reader --
Researchers from Japan’s ATR Computational Neuroscience Laboratories have developed new brain analysis technology that can reconstruct the images inside a person’s mind and display them on a computer monitor, it was announced on December 11. According to the researchers, further development of the technology may soon make it possible to view other people’s dreams while they sleep.
The scientists were able to reconstruct various images viewed by a person by analyzing changes in their cerebral blood flow. Using a functional magnetic resonance imaging (fMRI) machine, the researchers first mapped the blood flow changes that occurred in the cerebral visual cortex as subjects viewed various images held in front of their eyes. Subjects were shown 400 random 10 x 10 pixel black-and-white images for a period of 12 seconds each. While the fMRI machine monitored the changes in brain activity, a computer crunched the data and learned to associate the various changes in brain activity with the different image designs.
Then, when the test subjects were shown a completely new set of images, such as the letters N-E-U-R-O-N, the system was able to reconstruct and display what the test subjects were viewing based solely on their brain activity.
For now, the system is only able to reproduce simple black-and-white images. But Dr. Kang Cheng, a researcher from the RIKEN Brain Science Institute, suggests that improving the measurement accuracy will make it possible to reproduce images in color.
“These results are a breakthrough in terms of understanding brain activity,” says Dr. Cheng. “In as little as 10 years, advances in this field of research may make it possible to read a person’s thoughts with some degree of accuracy.”
The researchers suggest a future version of this technology could be applied in the fields of art and design — particularly if it becomes possible to quickly and accurately access images existing inside an artist’s head. The technology might also lead to new treatments for conditions such as psychiatric disorders involving hallucinations, by providing doctors a direct window into the mind of the patient.
ATR chief researcher Yukiyasu Kamitani says, “This technology can also be applied to senses other than vision. In the future, it may also become possible to read feelings and complicated emotional states.”
The research results appear in the December 11 issue of US science journal Neuron.
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