T I M E M A N A G E M E N T
that a dog’s eyes move behind closed eyelids when it dreams its
doggie dreams).
Sleep deprivation experiments (which must rank fairly high on
the sadism scale) have clearly established that we need to sleep.
Bad things happen when you keep folks awake for days at a time.
But even here, the conclusions are murky, because some of the
same bad things happen if you let folks sleep but deprive them
of their dreams (another feat of cruelty accomplished by rous-
ing sleepers every time they slip into the REM cycle but allow-
ing them otherwise to get their “normal” sleep). After a few days
of dreamless sleep, folks start having dreams, or delusions, while
they’re awake, displaying the symptoms of schizophrenia. (In case
you’re getting worried—you do dream, although you might not
remember your dreams.)
But we don’t know why we dream. For that matter, we don’t
even know for sure why we need to sleep at all. There have been
lots of theories, but research has failed to bear any of them out.
One compellingly logical notion, for example, posits that we sleep
so that our poor hyperactive brains can cool off. But now we know
that the brain is actually more active while we sleep. Different
centers light up, true, but the brain certainly isn’t resting.
On the all-important question of how much sleep we need,
experts are divided. Some side with Mom, suggesting that most of
us do indeed need between seven and nine hours of sleep a night,
with Mom’s eight a reasonable average. But others suggest that
“normal” sleep varies widely with the individual. Thomas Edi-
son is often cited as an example of a highly creative and produc-
tive individual who thrived on three or four hours of sleep a night
(although revisionist biographers have suggested that Edison took
a lot of naps, and some even suggest that his alleged nocturnal
habits are folklore).
So, we don’t know for sure why we do it, and we don’t agree on
how much of it we need. What do we know about sleep?