an estimated 24,000 people die each year in accidents caused directly or in part by falling asleep at the wheel.
We never know we’re sleeping while we’re asleep.
The first, and by far the most important, is that sleep erects a perceptual wall between the conscious mind and the outside world.
The second defining feature of normal sleep is that it is immediately reversible.
Dreams therefore represent “the royal road to knowledge of the part the unconscious plays in mental life,” wrote Freud.
“Drowsiness is red alert!”
I now think of the continuum of sleepiness and alertness as the state upon which all human behavior is acted out.
People’s own internal arousal processes, or some external demand (such as playing sports or driving a car) can make people feel pretty good and not sleepy at all. But this temporary arousal is a dangerous state, because sleep can overtake the brain the moment the arousal ceases or the person relaxes.
Right now we know only that the brain keeps an accurate count of sleep debt for up to two weeks, because that’s the longest controlled laboratory experiments have lasted.
the number of people killed or maimed in accidents caused by sleep deprivation may exceed the number killed by far-better-funded diseases.
sleep debt is known to lower productivity and increase a tendency to be angry or violent.
When a crash is attributed to alcohol, the real culprit, or at least a coconspirator, is often sleep deprivation.
People can be just fine driving after a single drink one day (when they have little sleep debt), yet be a hazard to themselves and others if they have that same drink on a day in which they have a large sleep debt. A fact little known by the public at large is that in nearly every accident linked to alcohol consumption, sleep debt almost certainly plays a major role.
This suggests to me that primates, including man, are able to compress their daily need to sleep into eight hours because they sleep more deeply and much more continuously than if there were no period of sustained wakefulness.
At certain times each day, our brains are powerfully stimulated by our biological clocks. At other times, the stimulation subsides or is turned off.
In summary, the main reason we do not fall asleep as soon as we have been awake for a few hours is that the homeostatic sleep drive is strongly held at bay by the independent internal stimulation of the biological clock. The main reason that we can sleep through the night is that we have accumulated sufficient sleep debt during the day so that the unopposed homeostatic sleep process is free to operate all night long.
Our loss of sleep time and natural sleep rhythms is the tragic legacy of a single and profound technological advance – the light bulb.
A recent survey showed that over 80 percent of Americans believe you cannot both be a success at work and get enough sleep.
When a normal sleeper experiences severe difficulty sleeping, whether from stress, jet lag, or pain, the episode is no different from experimental sleep deprivation in the sense that the individual’s sleep debt is mounting rapidly and the tendency to fall asleep will become very strong.
I expect that this warning will be largely ignored, just as early warnings about the health risks of tobacco were ignored.
These stories may have a common root. They all may be products of very vivid “hypnogogic” (associated with sleep onset) hallucinations.
When REM sleep occurs so quickly, the dream story often begins exactly where wakefulness ended and is a seamless stream of consciousness from the real world to the dream world.
The most dramatic component of the narcolepsy syndrome is “cataplexy” – attacks of muscle weakness or near-total paralysis that occur suddenly, last for a few seconds or minutes, and vanish.
Contributing to the strangeness of cataplexy is the fact that an attack typically is precipitated by strong emotion – anger, laughter, or just getting excited.
One thing I learned while trying to do experiments is that humor is extremely fragile in a laboratory setting.
We floundered like bombing stand-up comics, until we found that allowing subjects to view the television show I Love Lucy worked.
Occasionally people with narcolepsy are neither clearly awake nor clearly asleep; they may be existing simultaneously in two entirely different states of mind.
Surveys conducted to evaluate quality of life for people with narcolepsy have found that patients often suffer from double vision, memory problems, balance disturbances, and personality changes.
Half as many women develop narcolepsy as develop breast cancer, and the disorder is five times more common than leukemia.
As with humans, canine narcolepsy doesn’t involve pain. The dogs simply collapse, albeit dramatically when they get excited, for example when we give them a new toy or a favorite snack.
I imagine that wild animals with narcolepsy would not survive very long, since any tendency to collapse when frightened would quickly lead to the animal becoming dinner for a predator.
In narcolepsy, the muscle paralysis of REM sleep intrudes into waking life. In REM behavior disorder, muscles that should be paralyzed during REM sleep are not.
These are two examples of parasomnias (Latin for “near sleep”): sleepwalking and night terrors.
Some years ago in an anonymous survey. 42 percent of the house staff of a San Francisco hospital admitted killing at least one patient by making a fatigue-related mistake.
we do know that 33 percent of traffic accidents are traceable to sleepiness.
a large sleep debt “makes you stupid.”
In this complex and roiling symphony of interaction, it is impossible to separate cause and effect. Does sleep prompt tissue growth, or does the process of tissue growth, through the action of growth hormone, prompt sleep? Does the immune system govern sleep, or does sleep govern the immune system?
This experiment may be evidence of the real reason we forget most of our dreams, so as not to confuse ourselves. If we remembered every dream clearly, it might become difficult to sort out what really occurred and what was a dream.
Besides having mastery of a domain of knowledge, creative thinkers must possess an intrinsic motivation. And essential to sustaining this motivation is the ability to take pleasure in the creative act. Finally, they need to be able to hold paradoxical ideas in their mind and resolve the seeming contradictions. To make this extralogical leap they must be open to new ideas, question their own assumptions, and examine existing constraints.
the person who chooses to nap should be regarded as heroic.
-Excerpts taken from The Promise of SLEEP, by William C. Dement, M.D., Ph.D., and Christopher Vaughan