WHAT IS SLEEP?

Otago Daily Times, Issue 22563, 6 May 1935, Page 18

WHAT IS SLEEP?

NOBODY KNOWS WHAT OBSERVERS FOUND SOME COMMON IDEAS WRONG. Science has been investigating sleep for years and has discovered many things about it, but we are still without a definition of the word. Ten p.m. is the best time for sleep. After' midnight we miss- the soundest sleep. . . . Loss of sleep in childhood means ill-health, bodily and mentally. . . . All these things have been conveyed to us, but we still do not know what sleep is. Concentrated essence of rest is sleep, writes Martin Raymond in the London Evening Standard, and men who are able to snatch sleep at any time of day or night are looked upon as models of inexhaustible energy. Mr Lloyd George is reported to be such a one. Another was Thomas Edison. Napoleon slept between battles. John Wesley was similarly endowed by Nature. But until recent years nobody had probed this question of sleep to find out just how the normal person slept. Commerce was at the back of the investigations. First, in 1903, a Berlin doctor, Wolfgang Weichardt, invented an antitoxin for fatigue. Trade was good, and men believed they had something better to do than spend one-third of their lives in bed. ,- But though the invention was patented, it petered out, and now lies buried along with other " inventions " that for a brief, time threatened to rock human life to its foundations. : , If Dr Weichardt's discovery had achieved what was expected of it, certain lines of commerce would have had a shock. Beds would have become waste of meney. The sheet, blanket and pillow makers would have pulled down their blinds. The demand for mattresses would have vanished overnight. But it failed. And with its failure the German doctor fades out of the picture. SLEEP RESEARCH. Thirty years afterwards one of those mattress makers whom he threatened with destruction takes up the trail. Z. G. Simmons, an American, employs scientists, for he believes he can capitalise facts concerning sleep in selling more mattresses. In six years the mattress maker,spent £27,000' on sleep research. Then' came sleep of an unwanted kind, the depression that put whole American industries to bed, including .the mattress trade. The flow of money stopped, but not before many facts hitherto unknown even to the" most eminent doctors had been revealed. The manufacturer stayed the course to- the limit, for, with grim irony, he was himself a martyr to insomnia. In the first of the six years he put down a lump sum of £SOOO to provide a special, sleep laboratory at the Mellon Institute of Industrial Research in Pittsburgh. With this backing Dr Harry Johnson, of Ohio University, started work in earnest. MOVES OF SLEEPERS. He fixed up a special bed - with an automatic recording machine connected to the springs. It noted faithfully each move the sleeper made during the night. Hidden in a' wall-niche was a cinecamera, ab3o automatic. It photographed the sleeper each time he moved into a fresh position. The experiments produced 2,500,000 movement-measurements from 160 different subjects, and 20,000 photographs of their sleeping postures. What were the conclusions?

Many people pride themselves on their stillness during sleep— " hardly stir all night; I slept like a log," they boast. But the investigations showed that the normal person, in first-class health, moved at least 35 times during the night, and seldom stayed in the same position more than eight minutes at a time.r /

If you move less than the prescribed number of times to-night there is something wrong. Why? It is quite logical. The complex muscular system of the body makes it impossible to rest all the muscles at the same time. So they must take it" in turns, and they are sufficiently considerate to allow you to move from right to left, from straight out to curled up, without jerking you back to consciousness or even disturbing you unduly. Complete relaxation, Dr Johnson found, was so rare that hardly a single case was noted, for such a condition is unhealthy, unnatural, on the fringe of death.

Excess of movement is generally due to a heavy meal, to hot weather, or & too hot room. It is followed by insufficient rest to refresh the body, and the sleeper wakes tired and depressed.

Too little movement comes from overfatigue, from insufficient fresh air, faulty digestion or maladjusted bede — too narrow, or coverings too heavy to allow easy breathing.

Children move in their beds more than adults. Old people move less. Manual workers rest for longer intervals than brain workers. Women asleep are 30 per cent., more peaceful than men.

More data from the laboratory. What was all this to the mattress maker? Too narrow beds had been proved bad for sleep. He might icash in on the research and sell wider beds and more of them. The controversy of hard versus soft mattresses had been settled. But the answer was a dull compromise!, Bince the investigations showed that mattresses should be neither too soft nor too hard. Then the mattress maker took no further interest in the question. He died. STUDY OF CHILDREN. But the work went on under other auspices and with other scientists in control. They gave up adults and studied children. They confirmed some theories. Others they confounded. Birthday parties and Christmas toys made children more restless. Baths in the evening, hot or cold, had little effect. Nor did intensive brain work shortly before bedtime disturb their normal rest. Ono thing was found to improve rest and that was warm milk. But at what point are you asleep? What part of the body goes off first? Nobody really knows, but it is certain that the deepest sleep is during the first two hours of slumber. . You begin by becoming more or less unconscious—" more or less " becnur 3 some people will answer questions though apparently asleep. Eyeballs roll upward and outward. Your blood pressure falls, your heart beats more slowly. The flow of blood in the brain diminishes—although on that point there is room for doubt. But your lungs produce less carbon dioxide and your blood becomes less alkaline. ' RECHARGING THE BATTERY. All these happenings are consistent with the knowledge that sleep is the time when the body's battery is recharging in preparation for the morrow's demand for power. Without this recharging the starting becomes more and more sluggish, until, if discharge is persisted in, the engine stops for good. Dogs deprived of sleep die from sheer exhaustion. Man behaves in much the same way, but is more prone to preface death by going out of his mind. Insomnia is the prelude, and insomnia, though not a definite disease, is a gruesome malady. " Insomnia is a kind of third mortgage on the human body held by death. Like other mortgages it must be paid—the penalty of default is foreclosure."