Vivid Dreams Might Be Key to Feeling Well Rested When You Wake Up, According to a New Study
The findings could help explain the purpose of dreams and help physicians better treat people with sleep disorders
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Immersive, vivid dreams can create the perception of deep sleep, researchers report in a study published March 24 in the journal PLOS Biology. The findings might help explain the purpose of these nighttime visions and could lead to improved treatments for sleep disorders.
“Our study suggests that dreams may help shape how we experience sleep by immersing us in an internal world that keeps us disconnected from the external environment,” the study co-authors say in a statement.
The study involved 44 healthy adults who had electrodes placed on their heads to record their brain activity and then fell asleep in a lab. Each participant did this for four nights, during which the researchers repeatedly woke them up and asked about their most recent mental activity, as well as how deeply they felt they had been sleeping and how sleepy they currently felt. The scientists then compared those subjective reports—a total of 1,024—with the corresponding brain activity recordings.
The team primarily roused the participants during what’s known as Stage 2 NREM sleep, a phase of light-to-medium snoozing that makes up roughly 50 percent of total sleep time and occurs in cycles throughout the entire sleep period. This phase produces a range of dream experiences and perceptions of sleep depth.
Participants reported feeling the deepest sleep when they were awakened from either vivid dreams or moments when they felt they were deeply unconscious. It didn’t seem to matter whether they remembered the contents of their dreams—only that they’d had the impression of a rich experience.
“The quality of the experience, especially how immersive it is, appears to be crucial,” says study co-author Giulio Bernardi, a neuroscientist at the IMT School for Advanced Studies Lucca in Italy, in a different statement.
Key takeaway: Dreams are the “guardians of sleep”
Around the turn of the 20th century, Austrian neurologist Sigmund Freud famously wrote that dreams are the “guardians of sleep and not its disturbers.” The new research supports that view, suggesting that immersive dreams act as an “internal scaffold” that helps the sleeper remain asleep, the researchers write in the paper.
The electrode data revealed that when participants were having vivid dreams, they were also experiencing higher levels of brain activity. This finding challenges the view that the feeling of deep sleep arises only from periods of reduced neural activity.
“Not all mental activity during sleep feels the same,” Bernardi says in the statement. “This suggests that dreaming may reshape how brain activity is interpreted by the sleeper. … Rather than being merely a byproduct of sleep, immersive dreams may help buffer fluctuations in brain activity and sustain the subjective experience of being deeply asleep.”
What’s more, the work reinforces the idea that the perception of sleep is just as important as the quality. People with sleep disorders, for instance, often report feeling like they’ve had a bad night’s sleep, even when monitoring data shows otherwise. The study suggests that doctors treating these patients may want to focus not only on sleep duration and consistency, but also on dreams.
“It demonstrates that the perception of sleep depth cannot fully be explained by [brain activity] and the other way around,” says Rick Wassing, a neuroscientist at the Woolcock Institute of Medical Research in Australia who was not involved with the research, to the Australian Broadcasting Corporation’s Amy Briggs. “We need to investigate this much more.”
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