Unlike what many people believe, when we go to bed and got some sleep, it’s not instantaneous. Before reaching the deep sleep we go through a series of phases or stages. Besides that, the whole dream is a cyclical process. This means that it is repeated in a same order.
Here we will explain what steps has the dream to help you know a little better what happens once we started to fall asleep:
- Stage numbness
How the name suggests, it is the moment we begin to fall asleep. The muscles begin to relax, breathing changes, becoming less violent and even brain activity slows down. Every time I woke up (either because of a nightmare, or a sound, or for any reason) this phase begins again. You may have broken the sleep cycle in half and restarts.
- Stage of light sleep
For about an hour, brain activity slows even though it may go through some changes in activity (fast-slow) before reaching the calm necessary. In this phase, the pulses will drop dramatically.
- Transition to sleep
Sometimes it is not even considered a phase. It is 2 or 3 minutes that pass between the end of light sleep and deep sleep onset.
- Delta sleep stage
This is when the body really rests. Also known how the phase of the slow sleep (in accordance with the speed of brain activity).
Is also known how the paradoxical sleep. This phase is the one that we are particularly interested, as it is when we dream. The brain becomes active (much) unlike the body, which is in a heightened state of relaxation. The name means REM (Rapid Eye Movements) and named for the speed at which the eyes move (even if they are closed and no perceived eyeballs moving under the eyelids at high speed). A quarter of the time we do we sleep in REM sleep.
Each time we make the four stages NREM and REM sleep, we say that we have completed a sleep cycle. The duration of each phase varies depending on the time of night in which we find ourselves. Thus, as we have more REM sleeping time will be longer.
Some pathologies how narcolepsy alter the order of sleep stages beginning with REM (hence you can fall asleep instantly).