We tend to think we only dream during certain periods of the night, but that is not exactly true. Sleeping and dreaming are complicated—far more is going on than we ever remember on waking.
Each night we go through four to six sleep cycles. Each of these cycles has four neurologically different stages of sleep. All together, that is about 20 different sleep phases every night!
The four sleep stages consist of three periods where rapid eyes movements are not present (NREM sleep N1-N3), followed by one period in which the eyes rhythmically move from side to side (REM sleep). Think of one sleep cycles like an ocean wave that rise through different NREM phases to eventually break and foam in the form of REM.
In the past, it was believed we only dream during REM sleep. Certainly REM dreams are the ones we recall most easily. They usually have objects and people, have emotional feeling with vivid imagery and often a bizarre story line. These are the dreams that can lead us toward deeper insights and understandings of our inner self.
Recent research shows, however, that we do dream during NREM sleep, but these dreams have a different quality and content. As we drop off to sleep, we transition through a phase of hypnagogia with odd images, reverie, mini-stories and half-thoughts. These hypnagogic hallucinations draw us deeper into sleep but leave no lasting impression. If you can stay in that dreamy space and catch the mental gymnastics, it’s fascinating!
As we drift deeper into NREM, our dreams tend to be more thought-like, disjointed and related to experiences that made an impression during waking hours. In this state, I may rehash a stimulating TV program that left me with questions, or gnaw on a thought-bone, some issue that is bothering me. Occasionally I can even come to an interesting and useful solution to a problem.
NREM mentation may not feel like a real dreaming because it lacks vivid imagery, emotional impact and a storyline. Less elaborate and more similar to our ordinary thoughts, it slips away easily, though as I said, it helps process and even resolve important issue in our lives. Sometimes, if the NREM dream becomes stuck and repetitive, it interferes with the recuperative and healing powers of deep sleep and leaves us tired and listless in the morning.
It seems each aspect and phase of our sleep cycles has its own neurological, physical and psychological function. Rather than thinking of sleep as a period of blank nothingness, we should embrace and value its astounding complexity. Let’s widen our view of sleep to include all the many different states of consciousness and dream processes, including those we do not remember consciously.