Why do we dream?

We spend about a third of our lives asleep, and even if we don't always remember it, we dream every night. Sleep research has various theories about what exactly happens during dreams and why we experience vivid images and scenarios night after night. Here you'll learn why we dream and what happens in our brain during these dreams.

Table of contents

1. What does “dreaming” mean?
2. When do we dream?
   
3. What happens in the brain when we dream?
4. Why do we dream?

5. Conclusion

1. What does “dreaming” mean?

Our brain never sleeps. While awake, our consciousness is constantly active, and even during sleep, our body and brain don't completely rest. While important repair and recovery processes prepare our body for the next day, important processing takes place in the brain.
Dreaming is defined as the subjective experience we have during sleep and accompanies us for around a quarter of the time we spend asleep. Even though we often don't remember them after waking up, it's scientifically proven that almost everyone dreams. We then experience situations that, for example, address events from the previous day, work through conflicts and problems, or revive connections and relationships with people we know. However, the place, time, or action are often bizarre and surreal – we all know that. So what is the purpose of these subjective experiences at night, and what happens in our brain when we dream?

2. When do we dream?

During sleep, many regenerative processes take place in the body. Each night, we go through several sleep cycles, divided into different sleep phases. The onset and light sleep phases are followed by deep sleep, which then transitions into REM sleep.

› REM sleep

REM stands for "rapid eye movement," because during these periods of sleep, we move our eyes rapidly back and forth under closed eyelids. At the same time, blood flow to the brain increases, blood pressure rises, and our heart rate and breathing become more irregular. What else happens during sleep?

During deep sleep, the metabolism is running at full speed, growth hormones are produced, and cells are repaired and renewed. During the REM phase, these physical regeneration processes pause, and the brain begins to process information and impressions from the day. In short: Memory is formedToday we know that dreams occur in all phases of sleep, but are experienced particularly intensely during REM sleep. Therefore, those who wake up from this phase of sleep in the morning are more likely to remember what they dreamed.

Did you know? Women tend to remember dreams more often than men.

3. What happens in the brain when we dream?

To prevent us from moving and injuring ourselves during vivid dreams, the brainstem blocks the transmission of commands to our muscles. This state of immobility is also called sleep paralysis. The entire brain is then engaged to create precise dream images. Especially in the REM phases, scientists have been able to detect two special brain activities: While the areas responsible for processing emotions (the so-calledlimbic system) were even more active than when awake, the brain regions responsible for planning thinking (e.g. the prefrontal cortex) recorded less activity than when awake.

A good example of these observations is, on the one hand, the lasting effect of waking from an anxiety or nightmare, because we often experience the emotions evoked in the dream far beyond the actual dream experience. On the other hand, the reduced strategic brain performance is reflected in the frequent failure to adhere to physical laws – for example, when we breathe easily underwater or fly.

4. Why do we dream?

Why does our brain create these dream experiences during sleep? There are various theories about the meaning of dreaming. A widespread assumption is that our brain processes new information by comparing it with old information, mixing it, and storing it. It is also assumed that we reflect on certain situations in our dreams, and that the blending of old and new experiences serves as a problem-solving tool. Thus, working through issues that concern us and exploring different possibilities could help us resolve real-life conflicts.

Some scientists also assume that we dream to learn how to properly deal with fearful and dangerous situations. This has a completely natural background – because those who learn the correct behavior in dangerous situations and can consolidate this knowledge in dreams avoid danger.

5. Conclusion

Dreams accompany us every night, even if we wake up in the morning without any memory of them. Why the brain plays out vivid stories or unusual scenarios during sleep, and why we repeatedly experience both good and bad moments at night, cannot yet be fully explained. What is certain, however, is how important dreams are for our physical and mental health and also that they accompany us night after night as we sleep.

• Dreams are subjective experiences during sleep. We all dream every night—even if we don't remember them.

• Although we dream in every phase of sleep, dreams in the REM sleep phase are particularly intense.

• While we dream, the entire brain is active. Compared to the waking state, the brain areas responsible for emotions are more active during REM sleep, while the brain areas responsible for planning are less active.

• Why we dream is not entirely clear. Possible reasons include processing information, improving conflict resolution, or solving mental problems.

Best wishes and see you soon!