What defines a good night’s sleep? New research points to vivid dreaming as a crucial factor in feeling well-rested.
A study by the IMT School for Advanced Studies Lucca, published in PLOS Biology, analyzed 196 overnight sleep recordings from 44 healthy adults using high-density EEG. Participants were awakened during non-REM sleep to report their mental experiences and perceived sleep depth.
Contrary to long-standing belief that deep sleep requires minimal brain activity, participants reported the deepest sleep after experiencing immersive dreams - not just during unconscious states. Fragmented thoughts, however, correlated with shallower sleep perception.
"The quality of the experience, especially how immersive it is, appears to be crucial," said senior researcher Giulio Bernardi.
As the night progressed, participants felt their sleep deepened despite decreasing biological sleep pressure - a shift aligned with increasingly vivid dreams. This suggests dreams may help sustain the subjective sense of restorative sleep.
The findings could reshape sleep medicine, suggesting that dream quality - not just duration or sleep stages - may be vital to sleep health and mental well-being.
If confirmed, future therapies might target dream characteristics to improve how rested people feel, even when objective sleep metrics appear normal.