Sleep theory

In the field of sleep research, there is a wide range of theories: from particular to specific aspects of sleep, such as the relationship of REM sleep with dreams, to more general, the authors of which try to explain the need for sleep. This article focuses on the latter type of theories, which can be divided into five general categories:

1. Theories of recovery. Sleep is a necessary period of recovery from unhealthy states or states of exhaustion that develop during the waking period. This is the most ancient (proposed by Aristotle) ​​and the most common theory of sleep. Living organisms go to bed when tired, and awaken refreshed.
2. Theories of protection. Sleep helps to avoid continuous and excessive stimulation. Pavlov, directly, saw sleep as a cortical inhibition, contributing to the protection of the body from over-irritation. Living organisms sleep not because they are tired or exhausted, but to protect themselves from exhaustion.
3. The theory of energy savings. This theory arose from a study on animals, during which a strong link was found between high levels of metabolic activity and total sleep time. Since sleep, like hibernation, reduces energy expenditure, animals with a high level of metabolic activity reduce their need for energy due to the longer duration of sleep.
4. Theories of instinct. In these theories, sleep is considered as a species-specific, morpho-physiologically realized instinct triggered by environmental signals, with the necessity of causing a sleep response appropriate in a specific situation.
5. Theory of adaptation. This category includes the most advanced theories of sleep, which view sleep as an adaptive behavioral response. Proponents of this approach consider sleep a regular response to a timeout due to pressure from predators and the need for food. Thus, sleep is not a dangerous behavior (as from the standpoint of the theories of recovery), but an increase in survival response.

Sleep theories are often combined. Thus, both theories of defense and theories of instinct may include the concept of recovery. For example, Pavlov recognized the recovery function as part of his theory of protection. The theory of energy conservation and the theory of restoration can be considered as theories of protection. And the early version of the theory of adaptation included the concept of instinct as a mechanism of adaptation.

Theories of restoration and adaptation over time became the principal centers of opposition. The reasons for this are quite clear: each of the two theories is in good agreement with certain areas of sleep phenomena. The theory of recovery is consistent with the most important consequences of sleep deprivation: when a person or an animal is deprived of sleep, negative effects occur, and when they are poured out, these effects diminish. The theory of adaptation is consistent with a wide range of animal sleep data, reflecting the relationship of time schedules and total sleep duration to evolutionary pressures of the habitat. For example, grazing herd animals that are under heavy pressure from predators, tend to sleep for short periods, interspersed with awakenings, and the total duration of their sleep is only about 4 hours a day. The gorillas, who are practically unaffected by predators and have a limited need to find food, sleep 14 hours a day.

Both of these approaches encountered difficulties in explaining empirical material. According to the recovery model, there should be a direct link between wakefulness and its consequences. However, it turned out that the enhancement of sleep deprivation effects is not linear, but wavy. When test subjects are deprived of sleep for two nights, they cope better with performing various tasks on the third day than on the second night. Sleep time should be directly related to recovery time. However, some animals in just 4 hours of sleep restore the energy expended in 20 hours of wakefulness, while others need at least 18 hours of sleep per day. Intraspecific individual differences in sleep patterns reveal the shortest recovery time for the longest waking periods in every 24 hours. From the study of displaced sleep, for example, due to the transfer of people to another work shift, it is also known that sleep and sleepiness are affected by the time of day. On the other hand, supporters of the adaptation theories did not offer any explanation for the effects of sleep deprivation and were faced with an unforeseen question, namely, why the animal simply “does not stop the behavior” or does not rest instead of sleeping.

Both considered theoretical positions have experienced certain difficulties in the empirical substantiation of the mechanisms underlying them. Starting from the very first systematic sleep studies, attempts to find a "toxin" or a substance of "depletion", which regularly change during wakefulness and reveal the opposite change during sleep, have not ceased. At the moment, it was not possible to find such a substance, which, moreover, would have a strictly defined line of change depending on time. Theories of adaptation are compelled to rely on a non-strictly defined instinctive mechanism.

Since the 1960s. Began to build research chronology or temporal sleep diagrams. From experiments conducted in an environment devoid of signs of the passage of time, and studying the effects of a shift in sleep time in a 24-hour cycle (for example, due to a shift to another work shift), it became apparent that sleep is a synchronous system. Apparently, sleep can be viewed as an endogenously synchronized biological rhythm, organized on a 24-hour or circadian (Latin circa - around + dies - day) basis. For supporters of the theory of adaptation, it is becoming increasingly clear that an explanatory mechanism for choosing a suitable sleep time could be an endogenous biological rhythm mechanism.

Sleep - turning off the main volume of consciousness, lowering the reaction to the environment, rest and immersion in the world of dreams.

Ordinary sleep happens in time of day and night, regular and downed, sleep of the Lark and Owl sleep. According to the flow of sleep is calm and no, deep and superficial. Properly organized - the right dream. In addition to the usual sleep, they also talk about an inner dream - a dream of the soul. mind and spirit. See →

Correct sleep

Do you feel tired already at three in the afternoon? Obviously, your brain wants to take a nap. And it would increase your productivity. A single NASA study revealed that a 26-minute sleep improves the performance of pilots by 34 percent. Sufficient night rest affects the mental activity the next day. Good sleep is good thinking. Proper sleep is a necessary condition for mental and physical health. About reasonable duration and sleep mode, see →

How to quickly fall asleep

Perhaps you are not insomnia, but I want to quickly fall asleep, in 3-5 minutes. What helps? See →

How easy to wake up

An easy awakening begins ... before bedtime. This may seem unusual, but you can program your forthcoming awakening by falling asleep. See →

If the situation is more complicated, and even your favorite alarm clock is no longer able to help you wake up, then use the method “Imitation of lifting the alarm clock”. See →

Insomnia

Insomnia (difficulty falling asleep) is a common nuisance. How to deal with insomnia - see the article Insomnia.