Sleep Science Basics
What is Sleep?
People sleep at the equivalent of one-third of their lifespan.
About eight hours of sleep per night ads up to nearly three thousand hours per year.
Calculating from an average life expectancy of seventy years, this adds up to about twenty-four years of sleep.
The essential aspect, however, is the rhythmic alternation between waking and sleeping; everyday begins a new with approximately eight hours work, eight hours for our selves, for free time activities and family, and eight hours of sleep.
What Do I Do When I Sleep?
When we are tired in the evening we lie down. We go from the typical, upright human posture to a horizontal posture. As we fall asleep, what takes place? Consciousness vanishes.
- Everything around us remains as it was, but we do not perceive anything through the door of our senses. In contrast to comatose states or induced unconsciousness, we can still be awakened.
- During sleep, our perceptions of sorrow, delight, happiness, and worry are temporarily erased. Also pain is not felt. As long as I can feel pain I am awake. When I am able to fall asleep, the perception of pain disappears even though the cause is still present.
- During sleep our conscious, mental activities such as thinking, feeling, and willing are dulled. We lay in bed without any conscious activity and when we awaken the next morning we are rested, refreshed, and strengthened.
- We move during sleep, but it is involuntary, undirected movement. (During sleep-walking [somnambulism] the person moves without the participation of the consciousness.)
- We go to bed in the evening feeling tired and exhausted and we awaken in the morning feeling fresh and energetic. Is that not a miracle? These processes appear as a matter of course and we notice them only when something goes wrong.
- Our tissues have been supplied with more absorbent, watery-lively substance: We are rejuvenated. For instance, our inter-vertebral discs have gained fluid and we are up to one centimeter taller in the mornings than in the evenings.
- During sleep the physical body lies in bed. However, the body does not disintegrate, as is the case after death; it lives. The functions of building-up, growth, and regeneration are taking place more intensively during sleep than in our waking state.
In modern sleep research, sleep is divided also into four stages which occur in connection with the dream phases, the so-called REM phases (times of rapid eye movement behind closed lids).
- Stage 1: Falling asleep
- Stage 2: Light sleep
- Stage 3: Middle-deep sleep
- Stage 4: Deep sleep
Stage 1: It is the transition between waking and sleeping, the falling-asleep stage.
Stage 2: In stage two of sleep we lose our normal consciousness as the spiritual-soul detaches itself from material processes.
Stages 3 and 4: Middle-deep sleep transitions relatively quickly into the deep sleep stage. Deep sleep is the deepest of all the stages. Above all, physical regeneration occurs during this stage. Body movements often appear at the end of this stage. Body movements guarantee the essential feeling of refreshment after sleep.
REM Phase of Sleep
From the viewpoint of modern sleep research, the REM phase of sleep is accorded a soul-cleansing function. We see that during sleep we are in no way merely ruled by peaceful quietude and that the sleeping state is not passive, not “nothingness,” but rather something in which very much happens.
Modern sleep research has also concluded that sleep is an active process, that the brain does not take a rest during sleep but only works in various ways than during the day, in some ways becoming even more active. This can be determined by an electroencephalogram, which measures electrical brain waves.
First, let us take a closer look at the measured stages of sleep as they have been put forth by sleep research scientists. The sleep profile below outlines the sequence of the various phases of sleep.
After the first stage has ended, which is a transitional stage between waking and sleeping, the second stage, light sleep, begins. Many researchers see this second stage as the actual beginning of sleep. The third and fourth stages are often referred to together as the stage of deep-sleep.
After a renewed transitional phase between waking and sleeping, there follows a totally new sleep quality, the so-called REM phase (dream-phase). Then a new cycle begins. In one night, this cycle is repeated four or five times.
The deepest sleep phases occur in the first two sleep cycles. In contrast, the REM phases become longer with each succeeding cycle. Stages one through four (non-REM sleep) make up approximately 70 to 80% of the whole sleeping period; REM sleep accounts for about twenty to thirty percent.
Roughly every ninety minutes a REM phase occurs which lasts twenty minutes on average but increases in length throughout the night. Deep sleep and REM sleep demonstrate a counteractive duration.
After the first stage of falling asleep, sleep is deeper and therefore it is more difficult to awaken a person. Physical regeneration occurs mainly during the first stage. Towards the end of the night, dreams and soul-spiritual regeneration are at the forefront.
One additional note: REM sleep makes up a larger proportion of total sleep time for children than for adults.