Don: Say you're looking at an object on a table in front of you. How long do you think your eyeballs stay in one position?

看你一直在看你面前那張桌上的東西。你眼球能持續(xù)盯在一個地方多長時間？

Yael: You mean, how long before they move? I'm going to guess... a minute.

你的意思是，眼球能保持多長時間不動？我想……一分鐘吧。

D: More like less than a second.

更像是不到一秒鐘。

Y: Yow!

哎唷！

D: Though we feel as if our eyes stay completely still when we focus on something, researchers have found they only stay still at most for a couple seconds--often just a few milliseconds. What's fascinating about this is that every time our eyes move, we are momentarily visually impaired. We aren't seeing anything but a blur. So if we're always moving our eyeballs, and are always impaired, why don't we experience the world as a confusing rush?

雖然我們感覺我們在一直盯著某物看，但研究者發(fā)現(xiàn)，我們甚至至多只保持了幾秒鐘——往往是幾毫秒。有意思的是，實際上當每次我們的眼睛轉動的時候，我們會有短時的視覺失效。

我們看到的就是一片模糊。所以如果我們總是移動眼珠，視力總被削弱，那為什么我們沒感覺世界是一片混亂的呢？

Y: I bet you have an answer.

我賭你有答案。

D: Researchers at the University of Delaware have a good guess. They have done studies that show the brain is always extending the boundaries of what it sees-- adding in made-up information along the edges. This process is called "boundary extension," and it seems to be going on all the time. Say you're looking at a brick wall. You really only see a small section of it, but your visual processing system essentially says, "I can assume that beyond my visual field on either side are more red bricks, so for now I'll just add them in until I get better information." That process of

constantly extrapolating on what you see may be what allows you to experience a calm and consistent visual world, even though the actual data coming in is much more fragmented.

特拉華大學的研究人員有個很好的猜想。他們所做的研究表明，大腦總是人為擴充我們的視野范圍——添加一些憑空捏造的東西。此過程稱為“邊界擴展”，而且一直進行著。就拿你看著砌墻來說。你只是看到了一小部分，但你的視覺處理系統(tǒng)會告訴你，“我視線之外的一邊會有更多的紅磚頭，那么我就會一直給自己輸入這種信息直到我真的看到那一邊到底有什么為止。”在對你可能看到的事物進行持續(xù)的推斷過程中，你感覺到世界是平靜、持續(xù)不變的，即使實際接收到的信息是片斷式的。