The Stuff of Dreams
It is fairly clear that the sleeping period must have some function, and because there is so much of it the function would seem to be important. Speculations about its nature have been going on for literally thousands of years, and one odd finding that makes the problem puzzling is that it looks very much as if sleeping is not simply a matter of giving the body a rest. 'Rest', in terms of muscle relaxation and so on, can be achieved by a brief period lying, or even sitting down. The body's tissues are self-repairing and self-restoreing to a degree, and function best when more or less continuously active. In fact a basic amount of movement occurs during sleep which is specifically concerned with preventing muscle inactivity. If it is not a question of resting the body, then perhaps it is the brain that needs resting? This might be a plausible hypothesis were it not for two factors. First the electroencephalograph (which is simply a device for recording the electrical activity of the brain by attaching electrodes to the scalp) show that while there is a change in the pattern of activity during sleep, there is no evidence that the total amount of activity is any less. The second factor is more interesting and more fundamental. In 1960 an American psychiatrist named William Dement published experiments dealing with the recording of eye-movements during sleep. He showed that average individual`s sleep cycle is punctuated with peculiar bursts of eye-movements, some drifting and slow, other jerky and rapid. People woken during thses periods of eye-movements generally reported that they had been dreaming. When worken at other times they reported no dreams. If one group of people were disturbed for an equal period of time but when they were not exhibiting eye-movements, the first group began to show some personality disorders while the others seemed more or less unaffected. The implications of all this were that it was not the disturbance of sleep that mattered, but the disturbance of dreaming.
很明显睡眠有许多作用，而且是很重要作用。关于睡眠作用的探讨已经持续了几千年，而一个古怪的发现使问题变的复杂起来，似乎睡眠不仅仅是给予身体一个休息。“休息”从字面理解是肌肉的放松，可以通过短时间的平趟或者坐着来达到。身体组织在自我修复，并自我回复到一定水平。并或多或少保持最好状态。实际上，在睡眠时会保持一定量的运动，以阻止肌肉的不活动。如果（睡眠作用）不是让身体得到休息，那可能是让大脑休息？这可能是个似是而非的假设。有两个因素。首先，脑电图仪（一种将电极帖在大脑头皮记录电流活动的仪器）显示当睡眠中的活动方式变化时，总运动量没有任何变少的证据。第二个因素更加有趣和基础。1960年美国精神病学家William Dement发表了关于睡眠时眼睛运动的记录的实验。他提出正常人的睡眠周期可以被特殊的眼睛爆发式移动划分为几个阶段。有时慢，而有时则又急又快。当人们在眼睛动的很快时被唤醒，经常报告他们正在做梦。而在其他时间被唤醒的人们则说他们没有做梦。如果一组人连续几个夜晚都从他们眼睛移动时睡眠被唤醒，另一组人则在相同的时间但眼睛不运动时被唤醒。第一组的人会有一些紊乱，而第二组则看起来没有什么影响。这说明实质上不是睡眠被打乱，而是梦被扰乱了。
