SLEEP
SLEEP IS fundamental to good health and yet, it would
appear, many of us need a refresher course in sleeping. According to recent
surveys, about half of all men and women in the United States have trouble
sleeping at night, and about one fourth of the population use some form of
sleeping medicine. Before considering how sound, healthy sleep may best be
encouraged, let's get some basic understanding of this long-mysterious process
which has come in for scientific exploration only in recent years.
How much sleep do you need? Have you ever really tested
yourself over a period of time?
What is the nature of sleep?
Are sleeping patterns inborn or acquired habits?
What happens in sleep?
THE SLEEP PROCESS
As you have discovered when you do not get adequate sleep,
sleep is necessary for both physical and psychological well-being. Even now,
however, scientists are unable to explain why about one third of our lives must
be spent in sleep and why in our sleep we dream. In trying to get sound
insights into the mysteries of sleep, investigators in many sleep laboratories
use volunteers to whose scalp they tape electrodes to detect tiny currents in
the brain.
Amplified many hundreds of thousands of times, the impulses are
registered on graph paper as an electroencephalogram (EEG).
In addition,
equipment records pulse, eye movements, breathing, body movements, and muscle
tensions while the in sleep, it is now known, is not a state of oblivion, of
complete.
Rather, it is a progression of rhythmic cycles. Equipment, scientists have been able to
establish that sleep. That a newborn baby alternates between sleep and wakefulness
at about hourly intervals; that gradually, as the child grows older, the cycles
stretch out until eventually they becomes 90-minute cycles in adulthood.
These
90-minute cycles are beyond conscious control. It used to be thought that we
fall into deeper and deeper sleep during the night until we arrive at a turning
point, and then sleep lightens progressively until we wake up. But it is now
clear that this is not so. Instead, throughout the night, we shift from one
gradation of sleep to another and are even awake several times during the night
without necessarily remembering the wakefulness.
