Everybody dreams. H he human being spends a third of his life sleeping and, of that third, he spends at least another third dreaming, so that for a large part of our lives we live in an authentic dream world.

Both the question of why we dream and the interpretation of dreams have been a fascinating subject for humanity since ancient times, and have always been surrounded by an atmosphere of mystery, as no definitive theory has yet been reached about this creative process of our subconscious.

The first interpretations of dreams in history

In Mesopotamia, the Babylonians believed that dreams considered “good” were sent by the gods and “bad” were sent by demons. They had a goddess of dreams called Mamu whom the priests prayed to and tried to please in order to prevent bad dreams from coming true.

The Assyrians also interpreted dreams as signs. They believed that bad dreams were a warning and required action to correct the problem that had arisen in the dream. They thought that the person who had a bad dream should follow any advice he interpreted from the dream.

On the other hand, the ancient Egyptians believed that the gods revealed themselves in their dreams. They thought that these visions cause the real things that cannot be controlled or interpreted by the conscious. They wrote down their dreams on papyrus and differentiated between three types of dream experience: those in which the gods demand an act from the dreamer, those that contain warnings or revelations and dreams in which it was reached through a ritual. The three types of dreams served as a way to know the messages of the gods, as oracles.

Since the best way to receive divine revelation was through the dream, the Egyptians induced sleep in people who asked for answers from the gods . They traveled to sanctuaries or sacred places to lie down, sleep and dream in the hope of receiving advice, healing or consolation from the gods.

Why we dream: approaches from psychology

Psychology is no stranger to this interest and has approached the world of dreams from various disciplines (anthropology, neurosciences, psychology, literature…), although the reasons why we dream remain mysterious there are a number of interesting and relevant hypotheses and theories that try to explain why we dream.

1. Satisfaction of desires

One of the first and leading scholars of dreams was Sigmund Freud , who analyzed several patients and even used his own dreams as examples to prove his theory. He proposed that dreams represent the realization of a desire on the part of the dreamer, whether real or symbolic, including nightmares.

According to Freud, dreams are considered a collection of images of our conscious lives that possess symbolic meanings related to our subconscious desires .

For Sigmund Freud all dreams are interpretable and the dream does not have to be a totally real desire, but a symbol of something we want to happen, so he proposed that all dreams are interpretable.

2. Side effect

J. Allan Hobson and Robert McClarley in 1977 developed the theory of activation-synthesis . According to this theory, in the REM phase of sleep the circuits of the brain are activated, producing that the areas of the limbic system (including the amygdala and hippocampus) involved in emotions, sensations and memories are activated.

The brain tries to interpret these signals and dreams are the subjective interpretation of the signal generated by the brain while we sleep. However, the theory does not imply that dreams are meaningless but suggests that they are our most creative state of consciousness.

3. Keeping the brain active

Psychiatrist Jie Zhang proposed the theory of continuous dream activation, dreams being the result of the constant need of our brain to create and consolidate long-term memories for proper functioning .

When we are asleep, our brain automatically triggers the generation of data from the memory stores and this data is not shown in the form of feelings or thoughts but is experienced in our dreams. According to this theory, our dreams would be like a kind of random “screensaver” that our brain initiates so as not to turn off completely.

4. Forgetting: mental cleansing

Neuroscientist Francis Crick , together with mathematician Graeme Mitchiso in 1983 developed the theory of reverse learning.

The theory indicates that we dream to get rid of the connections and associations accumulated in our brain that we do not need to store. Therefore, we dream to forget as a kind of mental escape route, as if dreaming were a method of garbage collection or mental cleansing.

5. Consolidation of learning

At the end of the 19th century, the German psychologist Hermann Ebbinghaus, after various experiments and observations, indicated that dreams serve to consolidate what we have learned during the day. However, this theory was discarded by the scientific community because they considered that the brain is not active while we sleep.

In the 1950s Aserinsky and Nathaniel Klietman proved in several experiments that the brain continues to work while we sleep and is dedicated to processing everything it has acquired during the day . It reviews the memories formed recently, analyzes them and discards those that are irrelevant, enhancing and qualifying those that can be useful. However, how the brain performs this task remains a mystery.

6. Defense mechanism

The dream could be related to a defense mechanism. When we dream the brain behaves in the same way as when we are awake although the dopamine system associated with movement is not active . Therefore, such tonic immobility or playing dead could be considered as a defense mechanism.

7. Rehearsal

Dreams commonly include threatening and dangerous situations. The Finnish philosopher and pseudo-scientist Antti Revonusuo suggested the theory of primitive instinct of trial by which the function of dreams would be to simulate threatening events or situations and to test the perception of such threats in order to avoid them.

This theory maintains that the content of the dream has much meaning for its purpose. In addition, not all dreams are threatening or unpleasant and can also serve as practice or rehearsal for other situations.

8. Problem solving

Deirdre Barret, suggests that dreams are an avenue for problem solving. The author John Steinbeck called this the “Dream Committee”. As if it were a theatre, lacking the rules of conventional logic and the constraints of reality, the mind can create in dreams all kinds of scenarios solving problems more effectively than when we are awake. Therefore we tend to think that the best solution to a problem is achieved after we have slept.

9. Dreamlike Darwinism

Psychologist Mark Blechner states that dreams work as a natural selection of ideas that would serve to generate new ideas . Some research suggests that in the various situations we dream about we try to select the most useful reaction to successfully face those situations.

Dreams introduce variations useful to psychic life and internal narratives , produce variations to generate new types of thinking, imagination, self-awareness and other psychic functions

10. Processing of painful emotions

Finally, dreams could be considered as a kind of evolutionary therapy in which in dreams we do not select the best emotion or behaviour but serve as an outlet through the association of some emotions with symbols that appear in dreams.

In conclusion

These are just some of the more prominent explanations, as technology and research advances our ability to understand the brain will increase and we may one day discover the ultimate reason for our dreams. Today, despite all that we know about the physiology of sleep, dream thinking remains an enigmatic and controversial field.