I have memories in my dreams every day. Why?

Dream is a subjective experience, an imaginary image, sound, thinking or feeling produced by people in some stages of sleep, which is usually involuntary. People have not really understood the content, mechanism and function of dreams, but since prehistoric times, dreams have always been a topic of interest to philosophy and religion, and many related scientific conjectures have emerged. The scientific discipline of studying dreams is called the study of dreams. True dreaming has been directly confirmed only in humans, but many people think that dreaming may also happen to other animals. Animals have been proved to have REM sleep, but subjective experience is difficult to determine, but some domestic animals sleepwalk, so it is not surprising that they dream.

Dreaming mainly occurs during rapid eye movement sleep, which is a shallow sleep state in the later stage of sleep. It is characterized by rapid eye movement, pontine stimulation, accelerated breathing and heartbeat, and temporary limb paralysis. Dreams may also occur in other stages of sleep, but they are not real and hard to remember.

Most scientists believe that all human beings dream and sleep at the same frequency every time. Therefore, if a person feels that he has never dreamed or only had one dream in one night, it is because his memory of those dreams has disappeared. This kind of "memory erasure" usually occurs when a person naturally and gently enters the slow-wave sleep stage from the rapid eye movement sleep stage and enters the awake state. If a person is awakened directly from REM sleep (for example, by an alarm clock), they are more likely to remember their dreams during REM sleep (but not all dreams during REM sleep will be remembered, because a slow-wave sleep period will be inserted between active sleep, which will cause the memory of the previous dream to disappear).

Dreams vary in length, from a few seconds to 20-30 minutes. People who wake up during REM sleep are more likely to remember their dreams. Humans dream an average of 3-5 dreams every night, and some people have as many as 20 dreams. However, most dreams will be forgotten immediately or in a short time. As sleep enters the second half of the night, dreams will get longer. During 8 hours of complete sleep at night, most dreams occur in REM sleep, usually 2 hours.

In modern times, dreams are considered as a channel of communication with the subconscious. The content of dreams may be very ordinary and normal, or it may be extremely surreal. Dreams can have different themes, including fear, excitement, magic, depression, adventure or sex. The events in the dream are not controlled by the dreamer, and the dreamer will have self-awareness unless he is in a lucid dream. [8] Sometimes, dreams can make people creative or inspiring. One of the most famous stories is that German chemist Kekule claimed to have dreamed of a hadrosaur and realized the molecular structure of benzene ring. But his statement was questioned.

In different cultures and different times, people have different views on the meaning of dreams. At present, the earliest recorded material about dreams is a clay tablet in Mesopotamia about 5000 years ago. In ancient Greece and Rome, people believed that dreams were divination information from the dead and could predict the future. Some cultures hold dream incubation ceremonies, hoping to produce prophetic dreams.

Sigmund freud founded psychoanalysis, and expounded the theory and interpretation of dreams in many works in the early 1990s. He interprets dreams as expressions of people's deep desires and anxieties, which are usually related to repressed childhood memories or desires. In Interpretation of Dreams (1899), Freud developed a set of psychological techniques to explain dreams, and designed many rules to explain symbols and themes appearing in dreams. In the late19th century, psychotherapist sigmund freud developed a theory that dreams are driven by the satisfaction of unconscious will. Freud called dreams "the road to the unconscious". He founded the theory that dreams reflect the dreamer's unconsciousness, and believed that the content of dreams was shaped by the satisfaction of unconscious desires. He believes that important unconscious desires are usually related to childhood memories and experiences. According to Freud's view, dreams include explicit dreams and implicit dreams, which are related to the desires or fantasies in the depths of the subconscious, while explicit dreams are superficial and meaningless. Explicit dreams tend to cover up or obscure implicit dreams. In Freud's early works, he thought that the theme of most hidden dreams was instinctive sexual impulse, but he later gave up such an absolute statement. In his book Beyond the Law of Happiness, he considered how trauma or attack affected the content of dreams. In his speech "Dreams and Mysteries" in New Psychoanalysis, he also discussed the origin of supernatural ideas.

Carl jung opposed many of Freud's theories. Jung extended Freud's view that dreams are related to the dreamer's unconscious desires. He described the dream as a message to the dreamer, which can help the dreamer to improve himself. He believes that dreams reveal their emotional or religious problems and fears to dreamers. Recurrent dreams are intended to attract attention repeatedly, indicating that the dreamer ignores a theme in the dream. He believes that the symbols and images in these dreams will appear in all dreams. Jung believed that memories formed during the day were also important in dreams. These memories form an impression in the unconscious and need to be processed during ego (ego) rest. The subconscious will reproduce these fragments of the past in the form of dreams, which Jung called "the remnants of the day". Jung also believed that dreams are not purely independent, and all dreams are part of a "huge network of psychological factors".

Fritz Pierce believes that his dream theory is the core of Gestalt therapy. Dreams are regarded as the projection of neglected, rejected or suppressed parts of themselves. Jung claimed that everyone in a dream can be regarded as a part of the dreamer himself, which is called the subjective way of dreams. Pierce extended this view that even inanimate objects in dreams represent a part of the dreamer. Therefore, the dreamer is required to imagine himself as an object in his dream and then describe it to understand how the characteristics of the object are related to the dreamer's personality.

Long-term observation has proved that dreams have a strong correlation with rapid eye movement sleep. During REM sleep, EEG shows brain activity similar to waking state. After each period of non-rapid eye movement sleep (NREM sleep) (1~4) is awakened, even if there is a report of dreaming, the dream is dull and lifeless, but the concept and thinking are strong. Sleepers often report thinking about some problems instead of doing anything. During REM sleep, the release of neurotransmitters norepinephrine, serotonin and histamine is inhibited. A person's life, the typical dream time is 6 years. [48] Most dreams last only 5 to 20 minutes. Where does the dream originate in the brain? Is there only one source or many parts of the brain involved? And what effect does dream have on body and mind? None of these problems have been solved.

In most dreams, the dreamer doesn't realize that he is dreaming, no matter how absurd the dream is. The reason may be that the prefrontal cortex, which is responsible for logic and planning in the brain, reduces the activity during dreaming, making the dreamer interact with the dream more actively, regardless of what will happen, so what seems abrupt in reality can be integrated into the dream.

If you measure the length of a REM sleep and ask the length of the dream after waking the subject, as long as the dreamer has not had time to modify or forget the dream, he/she can accurately tell the length of the dream. Some researchers speculate that the so-called "dream time dilation" phenomenon will not really appear. The close relationship between REM sleep and dreams is the basis of the first reports describing the nature of dreams: dreams happen every night, not by accident; It is a high-frequency behavior, which occurs in every sleep cycle with predictable intervals, about once every 60-90 minutes.

At night, the sleeping and dreaming time of each REM segment becomes longer and longer. The first paragraph is the shortest, about 10- 12 minutes, and the second and third paragraphs will increase to 15-20 minutes. Sleep at the end of the night will be as long as 15 minutes, although there will be many independent clips, because you will wake up many times at the end of the night. When subjects wake up after their first REM sleep, 50% of them can report their dreams. When the last REM sleep was awakened, the proportion rose to 99%. The rising success rate of recalling dreams may be related to one-night dreams, in which images, colors and emotions are more and more vivid.