Thomas Edison said that sleep is "a bad habit." Like Edison, we seem to think of sleep as an adversary and try to fight it at every turn. The average American sleeps less than the recommended seven hours per night, mostly due to electric lights, television, computers, and smartphones.
However, we are ignoring the intricate journey we're designed to take when we sleep.
Dreams are hallucinations that occur during certain stages of sleep. They're strongest during REM sleep, or the rapid eye movement stage, when you may be less likely to recall your dream. Much is known about the role of sleep in regulating our metabolism, blood pressure, brain function, and other aspects of health.
One of the areas of the brain that’s most active during dreaming is the amygdala - the part of the brain associated with the survival instinct and the fight-or-flight response.
One theory suggests dreams may be the brain’s way of getting you ready to deal with a threat. Fortunately, the brainstem sends out nerve signals during REM sleep that relax your muscles. That way you don’t try to run or punch in your sleep.
One of the systems in the brain that wakes us up is the reticular activating system (RAS) - a part of your brain located just above your spinal column that acts like a gatekeeper or filter for your brain, making sure it doesn’t have to deal with more information than it can handle.
The RAS can sense important information and create neurochemicals that wake up other parts of the brain. It also keeps you awake throughout the day.
Once the RAS switch turns on, it can take some time for your whole brain and body to wake up. This is because it takes a few minutes to clear all the “sleepy” neurochemicals from your brain, which is why you may feel groggy when an alarm clock wakes you up.
One theory is that dreaming helps with sleep's memory-processing function. During sleep, the brain sorts through information gathered during the day, then decides what to keep and what connections to make between new information.
Another theory is that dreams help with emotional processing by removing some emotional associations.
Dreams may provide a safe way of testing the brain's reactions to negative events.
Or dreams are just the by-product of a brain starved of external input.
It is not genetics that determines whether you are an 'early riser' or an 'evening owl'. It is mostly habitual and environmental.
Early research found a connection between night owls and developing schizophrenia later in life. On average, owls also have lower wellbeing and are more likely to develop depression. It could be that owls are experiencing constant jet lag, which may put their bodies under stress.