Despite the fact that sleep and awakening are very different both in terms of content and sensations, both are deeply complex. It's no secret that the dreams of children differ from those of adults. Children dream emotional interactions with family members, friends and scary animals, and adults are dreaming of other adults. The dreams of young teenagers are filled with social interactions between the sleeper and his friends and important personalities. Dreams of a man are significantly different from women's dreams, with women dreaming equally of men and women, and men are more men than men. Adults see creative works, legacies and incessant problems in their dreams, and the dreams of dying people are filled with supernatural agents, the other world and visions of people who have long since left. Dreams that carry the child to the social world of his caregivers early in life, gently send the sleeper into the hands of loved ones when life comes to an end. Dreams accompany us literally from the cradle to the grave.
If we switch our attention from studying dreams that dream the rest of our lives and focus on dreams that are dreamed during the night, we will still find a significant heterogeneity. BDG (rapid eye movement) is replaced by episodes of sleep that do not belong to the BDG during the night, and as the morning comes on, the last episodes become shorter and the BDG is longer. We can spend up to 45 minutes in the BDG phase until awakening in the morning. Dreams seen in the BDG phase are very different from other dreams. The first are filled with aggression, but the latter are not. Dreams that are dreamed at the beginning of the night (mostly a phase of not fast eye movement) tend to ask an emotional problem that persists in other dreams that night. Emotional memories are passed back and forth between phases throughout the night until they finally settle in the form of a long-term memory in the cerebral cortex. The sleeping brain also actively gets to the older memories in the vault as the night progresses. The dreams of the BDG phase early in the morning contain more references to early childhood and memories of it than dreams that are dreamed at the beginning of the night.
Dreams differ not only within life or one night, they also differ within historical epochs. The dreams of the ancient Greeks and Romans, and indeed the dreams of ancient people, were considered portals to the spiritual world and the habitat of ancestors and gods. Ancient people (and even modern people) often dreamed of being able to contact the spirit of someone who asks for help or interferes with daily life.
Sleep states also vary in intensity: the more intense the physiological excitement during the BDG phase, the stranger is the content of dreams. For example, ordinary dreams about work are less intense than “big” and epic dreams. Such epic dreams often include scenes depicting fantasy worlds, which the dreamer visits frequently and repeatedly throughout several episodes of sleep. Ordinary dreams, on the other hand, contain completely normal and stereotypical content, when the dreamer does nothing special, only communicates with one or two familiar characters.
A slightly more intensive version of the usual dream about routine includes familiar and unfamiliar characters. Unknown characters usually appear in the role of male strangers and repeat their visits from sleep to sleep when they become more intense. With a high level of intensity, a dreamer and other characters are twisted into a series of events and actions, united by some goal-setting narrative. Characters are thrown into a rapidly developing dramatic story, with rapid changes in the plot and a bunch of emotional conflict. As the level of intensity increases, even more bizarre visual features penetrate into sleep. Extraterrestrials, impossible events, supernatural creations and metaphorical transformations of characters enter into sleep.
Characters in dreams not only differ from the waking consciousness of the dreamer, they can literally intercept control over this consciousness. The dreams of patients with dissociative identity disorder and multiple personality disorder may include manifestations of purulent personalities. Often the person from the wrong side first comes in a dream, and then takes control of the behavioral repertoire of a person and becomes an everyday person. A dreamer often experiences a transition from his primary personality to another during sleep.
Isolated sleep paralysis, in which a person can not move or speak after awakening, occurs when a part of the dreamer's consciousness is awake and the other remains in a state of sleep. The subsequent dream can be quite frightening: a person sees a hallucination of a malevolent presence, which somehow tries to interact with it. Most often, it is a demon whose purpose is to take possession of a person or destroy him.
On the other hand, false awakening dreams attract the subjective experience of awakening without removing a person from the state of sleep. The dreamer feels as if he has woken up, and then goes about his daily affairs, dressing and brushing his teeth. In fulfilling these routine tasks, the dreamer finally wakes up really. Often dreams in dreams contain references to previous scenes of sleep and characters. The dreamer can wake up in the same place where the dream passed before the false awakening. A dreamer can go through several false awakenings before he wakes up real.
There are also characters that we can only encounter with in a dream. Dead, for example, are never awakened consciousness, but can look into our dreams, looking alive and healthy and carrying a message for the dreamer. Such dreams, as a rule, clear, bright and intense, are felt as absolutely real.
What does all this mean? That a huge variety of states of sleep suggests that a dream is as important as waking for the biological state of the organism and, most likely, has many generative mechanisms and functions. For example, dreams of a dreadful, most likely, help us cope with threats in the daytime, and recurring dreams involving the same characters or places support or alter the cognitive architecture of the dream itself. Dreams come to us, regardless of what happens in a state of wakefulness, and most likely send us to something in a state of sleep, about which science is just beginning to guess.