Little is known about the purpose of dreams and many have spent hours trying to decode the meanings behind them, but these are not solidified in fact. There have, however, been investigations into what the brain does while dreaming.
The Scientific American reports that as humans we only understand about 10% of our brains. So understanding what happens to it while dreaming is quite a big feat.
Here are some interesting things about the dreaming brain:
1. It’s not off
It is easy to assume that your brain turns off, so to speak, during sleep. In fact, it is quite the opposite. At certain points, your brain is extremely active. During rapid eye movement (REM) sleep, your brain activity is nearly equal to when you’re awake.
2. It’s all so odd
Memories of events that have happened in your life, or episodic memories, are stored in the hippocampus. During REM, signals from the hippocampus are shut off. This means that while you’re dreaming, there is no access to your memories.
Access to general memories such as people and locations is still available, and these are the base’s of your dreams.
In addition, the regions which are involved in emotions and processing thereof are extremely active while dreaming. This results in a highly emotional overtone, bringing the general memories together.
The dorsolateral prefrontal cortex, the part of the brain which is in control of logical reasoning and decision making, is also off during this time.
This is why dreams so often make very little sense, and we are able to do the impossible in them.
3. It’s not only REM
In 1953 Eugene Aserinsky and Nathaniel Kleitman, at the University of Chicago, discovered that REM sleep is connected to dreaming. From then, it was assumed that dreaming only happens during this stage of slumber. That is, however, not the case.
According to recent experiments, dreams happen throughout the different phases of sleep but most of them are forgotten by the end of the night. The dreams in phases other than REM tend to be much more tame.
4. It’s not a ghost it’s sleep paralysis
Sleep paralysis happens either when you are falling asleep or waking up, when you’re between being fully awake and completely asleep.
People who experience this phenomenon claim to be unable to move, speak, and sometimes see hallucinations.
During REM the muscles are temporarily paralysed. So because you’re not fully awake yet, you still are unable to move and your dreams may continue into this state. This explains the experiences cause by sleep paralysis.
5. Visual and vivd
Parts of the visual cortex are very active during REM. A study by Japanese researchers suggested that the activated areas were broader during REM sleep than during visual stimulation.
For those who do not experience any visual stimulation, such as the blind, dreams are experienced differently. Studies suggest that people who were born blind experience intense references to the other 4 senses, and little to no visual images while asleep.
Bonus – Why do we dream?
The answer to this remains unknown. However, some have theorised that the purpose of dreams is to stabilise memories from the passed day and to prepare for events in the coming day. Others have argued that dreaming is connected to the activation of a “default mode” of our brains, which turns on as a result of a lack of external stimulation.
Freud’s theories that dreams are about wish fulfilment and desires have been refuted.