“Everything serious comes to us at night.” (CICERO)
What happens when we sleep?
Why do we sleep? The answer is not as simple as it seems. We sleep so that our body can rest, we think at first. However, science has not been able to prove concretely that sleep is necessary for physical recuperation of the body. Experiments performed on rats have proven that when deprived of sleep, these animals die.
But human nature is not as simple as that of rats. Everyone knows people who barely sleep. The most extreme case, published in some scientific magazines, is that of a man who claims not to have slept since contracting a serious illness. In a similar vein, some individuals with a highly developed spirituality are able to remain conscious all night. We’re not referring to a student during exam time drinking coffee or taking stimulants to stay awake more than twenty-four hours straight. We’re talking about people who can achieve advanced levels of relaxation through deep meditation.
It is known that anxiety and lack of concentration increase considerably after a night or two without sleep. One theory related to sleep affirms that we sleep to conserve energy. However, another suggests that we rest to conserve our food stores, since when we lose consciousness, we repress the hunger mechanism.
In the course of his life, a person has, on average, 300,000 dreams. As we age, both the time we spend sleeping and the time we spend dreaming decrease gradually.
Newborns sleep almost all day, alternating hours of sleep with short spells of wakefulness. By one year of age, they sleep fewer sessions but for longer in total: they have cycles of 90 minutes of sleep followed by another 90 minutes of waking time. Gradually, the child will sleep more at night and less during the day. By 9 years of age, most need between 9 and 12 hours of sleep a day.
The average for an adult is between 7 and 8.5 hours. But after age 70, we return to the sleep phases of childhood and sleep fewer hours continuously.
There are arguments that even claim we have slept since ancient times in order to appear a less tasty snack for nocturnal predators (when we sleep, our body looks like a corpse).
There are theories to suit everyone, but we shouldn’t forget the fundamental: for almost all of us, sleeping is a relaxing and pleasant experience that lasts between six and eight hours each night, an experience that is utterly necessary to “recharge the batteries” of our bodies.
It’s no coincidence that we choose nighttime to sleep. In the darkness our vision is reduced, the world becomes strange, and as a result, our imagination runs wild. Our minds remain occupied with images (that is, dreams). At night, our eyes don’t work, but we have a need to create images. If for some reason we are deprived of sleep, the following nights our dream production increases, since we spend more time in the REM phase (the period of sleep when oneiric thoughts are most active). Therefore it seems evident that we need dreams to live.
Some ancient civilizations believed that dreaming served, more than anything, to be able to dream. They were convinced that oneiric activity wasn’t the result of sleeping, but rather the reason for it. Some scientists, however, don’t share the theories of our ancestors when it comes to the reason behind our dreams.
There is a scientific school of thought that asserts that oneiric thoughts are simply a neurophysiological activity that comes with sleep. According to this theory, when we sleep we generate spontaneous signals that stimulate the sensory channels in the mind. The brain transforms these signals into visual images and induces the dreamer to believe that he is living real experiences.
Up to that point, perfect. But, why do dreams have such an interesting narrative? Why do they so often express metaphoric language? Why do they narrate stories that directly affect us? There is no concrete or scientific answer to these questions.
Other theories suggest that dreams serve to eliminate unnecessary facts from memory, since we can’t store everything that happens every day. According to this thesis, at night we erase the “archives” we don’t need, just like a computer.
The sleeping mind tests the process of erasing in the form of dreams, which would explain why they’re so difficult to remember. There are obvious limitations to this theory if you keep in mind that, occasionally, oneiric thoughts work creatively (they go beyond the information that we give them). These don’t have much to do with the merely “hygienic” function that the aforementioned scientific community claims. Often, dreams don’t eliminate the useless leftovers of daily experiences. Quite the opposite: they give them a surprising new shape, so when we wake up, we can reflect more deeply on their meaning.