Dreams are a combination of pictures and stories that our brain(mind) creates any time while we are sleeping.
But most of it happens during deep sleep where a brain is in his full activity during this period, and its know as the RES(Rapid eye movement) and its usually during the second half of your sleep, so how do dreams happen?
Your body feels sleepy due to increase in the natural adenosine compound during daytime Leading to lower blood pressure, slowing heart pulses and breathing, and relaxing muscles throughout the body.
Rapid eye movement
While you are sleep, your brain moves through 5 stages, one of them is the rapid eye movement or REM which happens after 90 minutes of sleeping and stays up to 10 minutes or more.
This stage may repeat several times during your sleep, and each time it increases. Your brain and your body will pass throughout different stages in this period as an increase in your eye speed, faster breathing, and higher blood pressure and sometimes a change in your body temperature.
In this stage, your brain is highly active while some of your body parts are temporarily semi-paralyzed.
How do dreams happen?
As we knew that in the rapid eye movement stage, your brain would be highly active; The cerebral cortex is responsible for your dream content and pictures.
The visual cortex at the back of your brain will be active, while parts of the frontal lobe are not or less active, which explains the inability of people during dreams to discriminate between reality and dreams and to accept the dream events as if they were real.
The brain then interprets and analyzes these activities and makes sense of the random signals that results and forms your dream.
Researchers point of view
Some researchers believe that dreams are nonsensical activities that have no goal or meaning made by the brain during your sleep, while others think that it is necessary and essential for your health, mind, and emotion.
Studies have shown that people who do not enter the stage of rapid eye movement suffer from anxiety and depression, Stress, difficulty concentrating, weight gain, and hallucinations.
Many researchers point out that dreams help in solving problems, addressing emotions, and merging memories. Sigmund Freud sees it as a window to the subconscious, a way to satisfy unacceptable desires in society.