The Mystery of Sleep

(by Graham Workman)

We may not give it a moment's thought, but most of us will probably spend one third of our lives asleep.

But how much sleep do we really need? In Florida, a volunteer was shut up in a special room for two weeks. He was allowed to sleep as much as he wanted, but there were no clocks in the room and the lights were always on. In other words, the only way he could tell if it was lunch-time, tea-time or bed-time was from what his body told him.

The man settled down to a regular rhythm of sleep and wakefulness. How much did he sleep? The same as about normal. The fact that he did this shows that his body must have an inbuilt mechanism, telling him to fall asleep and wake up.

What then is the purpose of this biological clock? Originally, it was probably a mechanism for survival. Sleep was a rhythmic process developed millions of years ago as a way of coping with life on a planet which had regular days and nights. Sleep protected people from the predators of the night and the inefficiencies of darkness.

All creatures sleep, but the amount they sleep varies greatly. This is because each species has an appropriate pattern of sleep that is suited to the world it inhabits.

An elephant has to spend most of the day finding food and eating it, so it sleeps only 2 hours a day. Of all living creatures only human beings get insomnia, because only they distort the natural rhythm of sleep with everything from anxiety to jet travel, from television to working round-the-clock.

But if we do not get to sleep at night, will it necessarily matter? Does it matter that night-shift workers do not get a normal ration of sleep? How safely can we make major decisions — perhaps life-or-death ones if we are prime ministers or doctors — when we have missed a lot of sleep?

One exception to all this is Lesley Gamble. He claims that following an accident 11 years ago, he never sleeps at all.

Researchers tested him by putting him into a darkened room with electrodes to see to what extent he was drowsy or slept. It is almost impossible for a sleepy person to lie down in a darkened room all night and not fall asleep. The recording showed him relaxed but awake all night.

He says he thinks most of the night, reflecting on happy events in his life which helps him to relax mentally.

How can a case like Lesley's be explained? It seems likely that his accident damaged in some way the operation of his biological clock and his body is no longer getting the order to sleep.

One way to find out if sleep is necessary is to take it away for three days and nights and see what happens, testing all the time which functions are affected most: our muscle co-ordination, our posture, our physical energy and strength, and most important, our mental vigilance.

Four students agreed to take part in such an experiment. After 36 hours without sleep they were still doing remarkably well at some things.

Interesting games, like chess, presented few problems for the sleep deprived. The tired brain can overcome fatigue if it wants to. Motivation, excitement and danger all keep us awake. The tired brain, however, is not good at boring, repetitive tasks. When the volunteers had to recognize short musical notes from a series of long and short notes, they made more and more mistakes as time passed.

After 72 hours without sleep everybody looked tired, their balance and muscle co-ordination had deteriorated and their mental vigilance had dropped. But basically there was nothing wrong. Heart, lungs and muscle strength were all fine.

In fact the body can do very well without sleep. Provided it is given adequate relaxation and food, there are no adverse effects on the body and its functioning. So if you miss a lot of sleep you are still able to operate, although the risk of making mistakes is increased.

But if the body does not need sleep, why do people feel so awful when they are deprived of it? What are insomniacs actually complaining about?

The answer probably lies in our brains — the homes of our biological clocks. The body may not need sleep but millions of years of evolution have programmed our brains to sleep every night of our lives, and there is nothing we can do about it.

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