Everyone has dreams, whether we remember them or not. Sometimes they may be almost indistinguishable from reality, but sometimes they are so bizarre that we do not believe how our minds could have created them. But what is their purpose? Why do we have dreams?
A dream is defined as a series of images, ideas, emotions, and feelings that usually occur involuntarily in the mind during certain phases of sleep. Dreams usually occur in the REM phase of sleep, where REM means the phase of so-called rapid eye movement. This phase is characterized by a number of certain features, such as the rapid movement of the eyes just mentioned, the disconnection of the cerebral cortex from sensory stimuli, and brain activity that is very similar to the waking state. With a classic eight-hour sleep, the REM phase should last approximately two hours, more often towards the end of sleep and dough before waking up.
The explanation of the nature of dreams is perhaps as old as humanity itself and ranges from individuals, through various religions, to renowned scientific institutions specifically focused solely on sleep. In antiquity, people placed great emphasis on dreams, and some rulers even built their decisions on dreams. For example, the Egyptians wrote their dreams on a papyrus and interpreted them as messages from God. The ancient Indians mention in the texts, among other things, what Sigmund Freud later proclaimed, that dreams express our inner desires. Jews, Christians and Muslims give dreams a supernatural character, as captured in their holy books.
Dreams appear both in the REM phase of sleep and in the NREM phase of sleep, but dreams in the REM phase are often bizarre and we often remember them when we wake up. Dreams in NREM, on the other hand, rather reflect events or feelings that actually happened to us, and the brain filters them and stores them in long-term memory. The reason we don't find bizarre dreams strange in the REM phase is that during this phase, the activity of the prefrontal cortex, which is responsible for logical thinking and planning, is slowed down.
The importance of dreams was studied in the 19th century by psychotherapist Sigmund Freud, who claimed that dreams are a gateway to subconscious desires. These are divided into obvious and hidden, where the obvious, what we really see, mask hidden, what we really desire. However, his theory was later challenged and overcome many times.
Contemporary science of dreaming is divided into two categories according to the nature of the interpretation, neurological and psychological. Neurological ones include, for example, Activation synthesis theory, which states that the brain generates sensory perceptions during the REM phase, which it also evaluates itself. True sensory perceptions are not created because sensory neurons are actively disconnected from the cerebral cortex during the REM phase. Continual-activation theory extends the previous theory. According to it, sleep is used to process temporary memory and store memories in the long-term one. In the NREM phase, conscious data are processed and subconscious data are processed in the REM phase. In the REM phase, the cortex is disconnected from the sensory inputs, which stimulates the flow of information through the part of the brain responsible for consciousness. This then manifests as a dream. Other researchers are presenting a theory of backward learning, according to which dreams help to clear memory of unimportant or incomplete inputs.
Psychological theories of dreams include emotional selection theory, which considers dreams to be modifiers and testers of mind maps to better capture a person's waking needs. The brain uses dreams to test how it would behave in given extreme situations that normally evoke feelings such as fear, shame, happiness and more. The tested maps are either selected or further modified.
Some other psychologists tend to the theory that dreams only continue to solve everyday's problems. Countless scientists, artists and other creative personalities testify to the fact that some of their works or solutions arose in a dream.
To sum it up, theories about the meaning of dreams can be written as follows.
- Dreams are only a by-product of sleep and have no function.
- Dreams help us test and modify our behavior and emotions in extreme situations.
- Dreams help us avoid vigilance in the waking state.
- Dreams help store memories in long-term memory.
- Dreams help us solve everyday problems.
Research into dreams is ongoing, and as new and new findings emerge, scientists will certainly reject some theories and create new ones. We also use increasingly accurate medical devices for this purpose, which can do amazing things today. Although we will have to wait for the essence of dreams to be resolved, one thing is certain now. Sleep and dreaming are essential for human health, and sleep deprivation, which is so popular in today's world, leaves great scars on our body and soul. Quality sleep and dreaming are more important than we admit.