A popular proverb says “ You don’t sleep to sleep, you sleep to be able to act . This simple sentence contains multiple truths about sleep, its physiology and its function. On average , about 29-30% of the day of a healthy adult individual is dedicated to sleep and over the course of life this percentage undergoes considerable fluctuations, due to various factors, but the constant is given by the need for a share of sleep. to be able to live.

>   1. How to define sleep

>  2. The stages of sleep

>   3. The myth of sleep

How to define sleep

“Temporary, spontaneous and periodic cessation of all higher psychic activity, characterized by the loss of consciousness of the external world, by the more or less complete abolition of the functions of the nervous centers and by the slowing down of the functions of organic life”  (A. Gabrielli, Grande Dizionario Italian – Ed. Hoepli).

There are various definitions of sleep, but taken individually they are not complete and if you compare them with the proverb quoted above, they do not contemplate all the implications that the act of  sleeping  brings with it. Because rightly “we do not sleep only to sleep”, that  is, it is not a condition for its own sake , it is not even a static condition.

In the different phases of sleep the  central nervous  system and part of the peripheral nervous system, the autonomic or vegetative one, establish important cellular and neuronal interactions, for some functions they are even superior to the waking state. “We sleep in order to act”:  sleep is functional to the energy regeneration of the body , it is a consolidator of memory and in this regard, various theories are associated and compensated to help answer the big question “why do we sleep?”.

But we sleep in order to act … even in sleep! Depression of consciousness and voluntary motor activity leave room for an organic and psychic world made up of energies, forces and levels of subtle interactions that complete the human being in his constant formation. The phenomenon of sleep involves the entire zoological scale, except for the lowest forms, and is considered a moment of recovery. 

Nature also lives its sleep, both the one linked to the nictemeral phase, and the seasonal one, the winter, in which everything is dormant, some animals fall into hibernation, to rest for the long year, protect themselves and restore themselves in view of the spring awakening.

 You can learn more about the properties and use of herbs that help you sleep

The stages of sleep

The act of sleeping involves a mental activity punctuated by rhythmic sequences of brain waves . The waking state is characterized by Beta frequencies , very short and rapid waves, which increase when the brain is called to face logical or mathematical complexities.

When one passes from wakefulness to sleep, however, the Beta frequencies disappear and the alternation of Alpha frequencies begins, characteristic of a state of rest, with Theta frequencies typical of a pre-conscious condition.

In the first phase of sleep, the Theta waves are followed by a period of Delta waves, which belong to the unconscious state, to the deepest sleep . This rhythmicity is repeated approximately every 90 minutes passing from long and slow waves to shorter and faster waves and is defined as the NON-REM phase (Non Rapid Eye Movement), followed by the REM phase , in which faster and faster Delta waves are revealed. brief appearances of Alpha and Beta waves. REM sleep is the sleep of dreams, in which the sub-conscious becomes active.

The myth of sleep

Each culture celebrates sleep and its myths and attributes different symbologies to it , from the ancient Greeks to the Egyptians, from the Romans to the Nordic peoples, from the Shamans of Latin America to the Yogis of the Far East. These legends represent an important key to interpreting what profound values ​​sleep has on the mind and on the human body.

In Hesiod’s Cosmogony we read that at the beginning only Darkness existed from which Chaos emerged. From their union were born Day, Night, Air and Erebus. Erebus and the Night gave birth to twins, Thanatos , god of death and Hypnos , god of sleep. A Persian proverb says ” sleep is the brother of death “.

On the symbolic level, in fact, sleep is closely associated with death , due to the loss of consciousness of external reality on the one hand and for the dream component that allows the individual to leave his physical body and wander through subtle worlds, on the other. Even the etymological analysis of some common terms such as “cemetery” testifies to this close symbolic link: from the Greek koimeterion = place where one sleeps, or “resurrect” from the Latin surgere = to get up.  Commonplaces re-propose this association, just think of statements such as “dying of sleep”, “eternal sleep”. By overturning the analysis plans in order not to fall into an excessively fatal symbology, it is possible to affirm that every awakeningin the morning you represent a new birth , the new day is a new portion of life.

According to the myth, Hypnos slept in a cave near the river Oblio   and his task was to save men from the tribulations of life for a few hours, making them fall asleep and causing them to dream. In this activity he was assisted by his son Morpheus, usually taking the shape of the people he dreamed of and appearing with a bunch of poppies with hallucinogenic power.

This myth illustrates how sleep can represent a refuge and a refreshment from the state of consciousness and activity, both for the body and for the mind: falling into Morpheus’ embrace is inviting and the natural way to seal an intense day of wakefulness. .