We spend around a third of our lives sleeping and even if we can't always remember it - we dream every night. In sleep research, there are various theories about what exactly happens while dreaming and why we experience vivid images and scenarios night after night. Here you can find out why we dream and what happens in the brain.
Table of Contents
- What does “dreaming” mean?
- When do we dream?
- What happens in the brain when we dream?
- Why do we dream?
1. What does “dreaming” mean?
Our brain never sleeps. When we are awake, our consciousness is continuously active and even when we sleep, our body and brain do not completely rest. While important repair and recovery processes prepare our body for the next day, important processing processes take place in the brain.
Dreaming is defined as the subjective experience during sleep and accompanies us around a quarter of the time we spend sleeping. Even though we often don't remember it when we wake up, it has been scientifically proven that almost all people dream. We then experience situations that, for example, address events of the past day, deal with 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 are these subjective experiences at night used for and what happens in our brain when we dream?
2. When do we dream?
Many regenerating processes take place in the body during sleep. Every night we go through several sleep cycles, which are divided into different sleep phases. The falling asleep and light sleep phases are followed by deep sleep, which then transitions into so-called REM sleep.
› REM sleepREM stands for “Rapid Eye Movement”, because during these sleep periods we move our eyes quickly under our closed eyelids back and forth. At the same time, blood flow to the brain increases, blood pressure rises and our heart rate and breathing also become more irregular. What else happens when you sleep?
During deep sleep, the metabolism runs at full speed, growth hormones are produced, cells are repaired and renewed. In the REM phase, these physical regeneration processes pause and the brain begins to process information and impressions from the day. In short: the memory is formed. Today we know that dreams occur in all phases of sleep, but are experienced particularly intensely in REM sleep. Anyone who wakes up from this sleep phase in the morning is more likely to be able 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 dreaming, the brain stem blocks the transmission of commands to our muscles. This state of inability to move is also called sleep paralysis. In order to create accurate dream images, the entire brain is then used.Scientists were able to detect two special brain activities, particularly in the REM phases: While the areas that are responsible for processing emotions (the so-called limbic system), were even more active than when awake, the brain regions responsible for planning thinking (e.g. b the prefrontal cortex) has less activity than when awake.
A good example of these observations is, on the one hand, the lasting effect of waking up from a fear or nightmare, because we often experience the emotions awakened in the dream far beyond the actual dream experience. On the other hand, the reduced strategic brain performance is reflected in the often lack of compliance with physical laws - for example when we breathe or fly with ease under water.
4. Why do we dream?
Why does our brain even create these dream experiences while we sleep? There are various theories about the meaning of dreams. It is widely believed that our brain processes new information by comparing, mixing and storing it with old information. It is also assumed that we reflect on certain situations in dreams and that the mixture of old and new experiences serves to solve problems. So working through issues that concern us and experiencing different possibilities could help us resolve real-world conflicts.
Some scientists also assume that we dream in order to learn how to deal with fear and dangerous situations. This has a completely natural background - because anyone who learns the right behavior in dangerous moments and can consolidate this knowledge in a dream avoids danger.
Dreams accompany us every night, even if we wake up in the morning without any memory of them. It is not yet possible to fully explain why the brain plays out vivid stories or unusual scenarios while we sleep and why we repeatedly experience both good and bad moments at night. What is certain, however, is how important dreams are for our physical and mental health and also that they accompany us in our sleep night after night.
Dreams are subjective experiences during sleep. We all dream every night - even if we don't remember it.
Although we dream in every phase of sleep, dreams are particularly intense in the REM sleep phases.
While we dream, the entire brain is active. Compared to the waking state, the brain areas responsible for emotions are more active in REM sleep, while the brain areas responsible for planning are less active.
Why we dream is not fully proven. Possible reasons include processing information, improving conflict management or solving mental problems.
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