Not all our dreams are the same!… Literally. Throughout the night, our sleep goes through various phases, each with particular characteristics. Therefore, knowing the basic structure of our sleep to understand this enigmatic activity.
Sleep goes through two major phases: NON-REM sleep and REM sleep. Next, I explain the main characteristics of each of these phases.
This phase is mainly characterized by slow-wave sleep. It is 75% of our total sleep and usually takes the first part of the night. NON-REM sleep is divided into four stages, which are:
** Stage I: This stage corresponds to transitional sleep, usually lasting a few minutes. In other words, it is the sleep that arises while you put your head on the pillow and fall asleep.
** Stage II: This is the light sleep stage. Although during this stage one sleeps peacefully, it is highly susceptible to interruptions. Consequently, any noise or movement might wake you up during this stage.
** Stage III and IV: Currently, scientists believe that these two stages are a single entity, so for now, we are going to group them. During these stages, deep sleep occurs.
I would dare to say this is the most critical stage since it is the most restorative sleep. At this stage, the body enters a state of hibernation in which physiological activity (e.g., temperature, respiration, heart rate) decreases considerably.
This phase occurs in a single stage and is characterized by daydreams (commonly known as dreams). It corresponds to 25% of our total sleep, and its presence increases as the night progresses. In addition to dreams, REM sleep is distinguished by rapid eye movements (the phenomenon that gives this stage its name) and partial paralysis of the body, which prevents us from acting out our dreams every night ... Can you imagine what that would be like?
Going through the two phases (NO-REM and REM) constitutes a sleep cycle. Each cycle has an average duration of 60 minutes in children and 90 minutes in adults. Therefore, an average adult has around six sleep cycles a night; children have many more. So, if you think about it, we have six different dreams throughout one night, even though we only remember one or none... Surprising, isn't it?
I hope this information gives you some light on how sleep is structured.
With no more to say, for now, I have no choice but to wish you a good night's sleep with complete sleep cycles.
Jové, R. (2018). Dormir sin lágrimas (26ª Ed.). Madrid, España.: La esfera de los libros.
Pedemonte, M. & Velluti, R.A. (2017). Fisiología general del sueño. En Viguera (Eds.), Sueño: Fisiología y Medicina (pp. 25 – 58). Murcia, España.: Viguera.
Esteban, S., Gamundí, A., Nicolau,M.C., Rial, R.V., De la Calzada, M.D. & Giménez, S. (2017). Filogénesis y ontogénesis del sueño y la vigilia. En Viguera (Eds.), Sueño: Fisiología y Medicina (pp. 104 – 136). Murcia, España.: Viguera.