時差N小時:跑步機與意識

Lots of people these days get their exercise at gymsand health clubs, oftentimes by walking or runningon treadmills—that is to say, running without goinganywhere. If you've ever been on a treadmill forsome time and then suddenly stepped off it, you'veprobably experienced the weird sensation that youare suddenly moving much faster than you think youshould be. Why?

這些天很多人去健身房、健康俱樂部鍛煉身體，時間大多花在跑步機上——也就是說原地不動行走或者跑步。如果你在跑步機上跑了一段時間，突然停下時，你心頭可能會出現(xiàn)一種古怪的感覺：你移動得比實際要快。為什么?

This deceptive sensation is the result of sending your brain two different signals at once. Thefirst signal is the one coming from your legs; during exercise they are in rapid, regular motion,and the brain understands by this fact that the body is moving through space. The secondsignal comes from the eyes, which are seeing that the objects around you are not passing by,and hence you are standing still. In a sense your eyes are disagreeing with your legs. The resultis that after about ten minutes of this input disparity, the brain recalibrates its internal senseof motion.

這種欺騙性的感覺實際上是大腦一次傳遞兩種不同信號的結(jié)果。第一種信號來自于你的雙腿，在鍛煉的時候它們快速，有規(guī)律地移動，然后大腦把這個事實理解成在空間里穿行。第二種信號來自于你的眼睛，眼睛看到的周圍的物體并沒有遠(yuǎn)去，因為你是站著不動的。在意識里，你的眼睛和你的腿是不一致的。結(jié)果，在這種輸入分歧之后大約十分鐘，大腦開始重新調(diào)整內(nèi)心的動作感。

In simple terms, your brain tells itself: this is how fast objects move by when I'm walking atthis rate, as opposed to what was formerly the case. That means when you step off thetreadmill and begin actually moving through space again, your recalibrated brain is now sentthe incorrect message that you have suddenly increased your speed significantly. Once again,what the legs say and what the eyes say is out of sync. The sensation of accelerated motion isonly temporary, though, and the ever-adaptable brain soon readjusts itself once more—untilthe next time you step up on that rolling, immobile track.

單純意義上來說，大腦告訴自己：當(dāng)我以這樣的速度行走時，身邊的物體也以同樣的速度在移動，不同于先前那種情況。這意味著，當(dāng)你跳下跑步機再次開始真正的空間運動時，你調(diào)整過一次的大腦將會發(fā)送錯誤的信息：你突然加度了。腿和眼睛傳達的信號再一次不同步。盡管加速運動的感覺只是暫時的，能不時順應(yīng)的大腦很快又會再次調(diào)整，直到下次你再踩在那滾動著但穩(wěn)定的軌道上。