To Sleep, Perchance to Dream

摘要

Most people think they don't get enough of it. Some manage just fine on half the usual amount. Dolphins do it with half a brain at a time. Rats die after three weeks without it, yet male Emperor penguins manage an entire three months of brooding without getting any. It's as good as ubiquitous among animals - even insects do it. We spend a third of our lives at it. Yet no one has any clue why we do it or how it came about. Our ignorance about sleep is: becoming something of an embarrassment. Try to think of another fundamental biological phenomenon to which we can't assign a role. You'll draw a blank. "I think it's the biggest unanswered question in neuroscience," says Craig Heller, a sleep researcher at Stanford University in California.