SLEEP DISORDERS

The idea that "Everyone needs 8 hours sleep" is not true. Newborns spend at least two-thirds of their day asleep, the elderly barely more than one-fourth. Age related differences in average time spent sleeping are rivaled by differences in the normal amount of sleep among individuals at any age. Some people thrive with less than 6 hours of sleep per night, other regularly sleep 9 hours or more. (among various mammals, the need for sleep varies more widely: Horse and Cows sleep only 3 to 4 hours per day, rats and cats 14 to 15 hours.

Although human sleep difference are not accompanied by striking personality differences, sleep patterns may be geneticaly influenced. When Wilse Webb and Scott Campbell (1983) monitored the patern and duration of sleep among fraternal and identical twins, only the identical twins were strikingly similar.
Whatever their normal need for sleep, some percent of adults complain of insomnia-recurring problem in falling or staying asleep.
The emphasis in this sleep disorder is on "recurring". True insomnia is not the occasional inability to sleep that we may experience when we are feeling anxious or excited. Alertness is natural and adaptive response to stress. We commonly underestimate the amount of sleep we get on restless nights. Even if we've been awake only an hour, we may think we've had insomnia much of the night, because that's the part we remember.

The two most common quick fixes for true insomnia, sleeping pills and alcohol, can aggravate the problem. Both tend to reduce REM sleep, and when their use is discontinued, the insomnia may worsen.

Sleep experts have other advice :

1. Relax before bedtime
2. Avoid rich foods aroud bedtime (Milk is good, because it aids in the manufacture of serotonin, a neurotransmiter that facilitate sleep).
3. Sleep on a regular schedule (rise at the same time even after a restless night) and avoid naps.
4. Reassure yourself that the temporary loss of sleep causes no great harm.

Rare but more severe than insomnia are the sleep disorders narcolepsy and sleep apnea. People with narcolepsy suffer periodic over whelming sleepiness, sometimes at the most inopportune times perhaps just after taking a teriffict swing at a softball or when laughing loudly:) or angrily. The person collapses directly into a brief of REM sleep, with its accompanying loss suffer from narcolepsy must live extra caution.

Those who suffer from sleep apnea intermittenly stop breathing while sleeping (apnea means "cessation of respiration"). After an airless minute or so, the decreased OXYGEN in the blood arouse the sleeper to snort in air for few seconds. The process is repeated hundreds of time during a night's sleep. Appart from sleepiness during the day-and their mates' complaints about their loud "snoring" apnea sufferers are often not aware of their disorder. Yet, were they not to become aroused and resume breathing, they would suffocate, as apparently happens to sleeping babies who mysteriously die of Sudden Infant Death Syndrome (SIDS), also known as crib death.

Still other sleepers are afflicted with night-terrors. The person often a child might sit up or walk around, talk incoherently, experience a doubling of heart and breathing rates, and appear terrified (Hartmann, 1981). The night terror sufferer very seldom awakens fully and recalls little or nothing the next morning at most a fleeting, frightening image. Ulike nightmares, which typically occur toward morning during REM sleep, but like sleepwalking, night terrors usually occur during the first few hours of sleep and during stage 4 sleep.


Part 3 : Experiencing the world.
Chapter 8 : State of Consciousness