Why Vivid Dreams Make for Better Sleep
Sleeping well is easier said than done. Sometimes you may collapse for hours and wake up groggy; other times, you wake up after a 45-minute nap, ready to take on the world. This is because the feeling Whether you’re well rested isn’t just a function of how much time you spend sleeping, it’s partly subjective. New research published today in Biology PLOS suggests that our dreams may play a role in this feeling.
Generally speaking, there are two types of sleep: non-rapid eye movement sleep (non-REM sleep) and rapid eye movement sleep (REM sleep). Non-REM sleep includes what is called “deep sleep,” characterized by slow brain waves, very little activity, and no awareness. REM sleep, on the other hand, is characterized by more awake brain activity and intense dreams, but it is also experienced as deep sleep.
So what’s going on?
To find out, neuroscientists at the IMT School for Advanced Studies in Lucca, Italy, recruited 44 adults to spend several nights dozing in a sleep laboratory while their brain waves were monitored using high-density electroencephalography. They then woke the participants during non-REM sleep, asking them to report their mental experiences before waking and to rate both the depth of their sleep and their current sleepiness.
Read more: “Does Dream Inception Work? »
They found that participants reported their deepest subjective sleep experiences not only after a period of unconsciousness, but also after particularly immersive and vivid dreams.
“In other words, not all mental activities during sleep are the same: the quality of the experience, particularly its immersive nature, appears to be crucial,” study author Giulio Bernardi explained in a statement. “This suggests that dreaming may reshape how brain activity is interpreted by the sleeper: the more immersive the dream, the deeper the sleep.”
They also found that although physiological markers of sleep need decreased throughout the night, participants reported feeling a deeper sense of sleep. This somewhat paradoxical phenomenon coincided with an increase in the immersive nature of dreams, suggesting that dreams themselves promote deep sleep experiences.
“If dreams help maintain the feeling of deep sleep, then alterations in dreaming could partly explain why some people feel like they are sleeping poorly even when standard objective indices of sleep appear normal,” Bernardi said. “Rather than simply being a byproduct of sleep, immersive dreams may help buffer fluctuations in brain activity and maintain the subjective experience of deep sleep.”
In other words, Sigmund Freud may have been right when he wrote: “Dreams are the guardians of sleep and not its disturbers.” » 
Enjoy Nautilus? Subscribe for free to our newsletter.
Main image: Natalllenka.m / Shutterstock
