REM is a stage where the human eyes make rapid/darting eye movements as the body enters deep sleep. This degree paralyzes the nerves creating a significant loss in muscle tone. It also lowers blood pressure, breathing, heart rates and causes dreams to occur.
While it virtually has the same characteristics, dreams are not hallucinations. But unlike scenes induced by schizophrenia and the likes, dreams, in contrast, are activated primary and secondary sensory cortices. It happens because the frontal cortex, which controls inhibition, are disrupted. Sometimes, when dreams tap something emotional, it might be a sign that the limbic system was involved in the process.
People call it “lucid dreaming” when you are aware that you’re in the premise of your dream. During this process, the frontal cortex shows to have increased activity compared to the typical REM sleep. Nowadays, humans and animals aren’t the only creatures to experience dreams. The Google artificial neural network creates images out of white noise. Results are intricate and beautiful images that the company calls as “AI dreams.”
All of these explanations and it still hasn’t answered the age-old question: “Why do we sleep?” While there are countless theories about the topic, no one still knows the answer to that. What the world knows about it is that it’s important for memory to stick in our brains and gives the body energy.
Sleeping allegedly cleans the slate to our body and mind so we can move and learn more the next day. The existence of sleep still has no definite reason, but the factors that we have in our hands right now are enough to make it an important part of any human routine.