Insomnia 175and at night searching for oases of grass and water to feed their camels
and sheep.Benefi ts of Dreaming
There are two kinds of sleep: the sleep when we don’t dream, called
orthodox sleep, which gets progressively deeper in four successive
stages; and a shorter period of sleep when we dream. Dream sleep is
called rapid eye movement, or REM, because while we dream the eye-
balls move rapidly. Some researchers think these two kinds of sleep
alternate in cycles throughout the night and that three-quarters of the
time we experience orthodox sleep and the other quarter REM sleep.
Dreams are most vivid the last two hours of an eight-hour period of
sleep.
Medical science has different opinions as to whether there are bio-
logical or mental benefi ts to dreaming. The fact that dreaming is
almost universal suggests it plays an important role in our health.
There are indications that not having dreams is unnatural. For exam-
ple, in a mental illness such as schizophrenia, as symptoms worsen,
the victim dreams less and less and fi nally stops dreaming altogether.
Also, people who regularly dream often become disoriented and anx-
ious when a medication they are taking prevents them from dream-
ing. The fears, resentments, and anxieties we experience during our
waking hours are often played out in our dreams, which is probably
why nightmares are so common. It is possible that bad dreams, by
giving us a chance to get the negative feelings “out of our system,”
lower stress hormone levels that rise when we become anxious or
depressed.
A study consisting of seventy-seven volunteers reveals that dreaming
can improve cognitive thinking.^2 The subjects were given a word asso-
ciation test and then underwent three different conditions: one group
spent a day without a nap, another group napped without REM (dream)
sleep, and the third group dreamed while napping. Spending a day
without sleep and napping without dreaming both led to slightly better
performances when the subjects were retested. But the group who
dreamed while they napped had a 40 percent higher score than the
other two groups.