“Immersive dreams”, keys to sleeping deeply

Immersive dreams, which involve an increase in brain activity similar to that of waking, cause a greater sensation of deep sleepaccording to research from the IMT School of Advanced Studies in Lucca, Italy.

Specifically, the researchers publish in PLOS Biology that The sensation of deep sleep is not determined solely by slow wave brain activity. Research has shown that our feeling of deep sleep is related to a shift of brain waves from high to low frequency, which is believed to induce unconsciousness.

At the same time, other studies indicate that REM sleep (dream with dreams) is also perceived as deepdespite their waking-like brain waves. To better characterize the effects of REM sleep on sleep depth perception, the researchers analyzed EEG recordings from 44 adults who were repeatedly awakened during non-REM sleep over 4 nights.

The analysis showed that changes from fast to slow waves were indeed associated with the sensation of deep sleep. However, this relationship weakened when participants reported dreaming, even if they did not remember its content. Therefore, perceived depth of sleep was greater after dreamingdespite the fact that this state is associated with brain activity similar to that of wakefulness. Specifically, vivid, strange, and emotionally intense dreams were associated with subjectively deeper sleepwhile abstract, reflective and meta-aware dreams were related to a more superficial dream sensation.

These findings contradict the traditional view that the sensation of deep sleep is governed solely by slow brain waves and the depth of unconsciousness, and suggest that perceptually immersive dreams are what allow us to feel well-rested, even if we cannot remember what we dreamed.

The authors add: “We already know that dreaming goes beyond the REM phase and occupies much of the night, but its function remains unclear. “Our study suggests that dreams can influence how we experience sleep by immersing us in an internal world that disconnects us from the external environment.”

Understanding how dreams contribute to feelings of deep sleep opens new insights into sleep health and mental well-being. Disturbances in dreams (e.g., a reduction in dream richness or frequency) could influence how people perceive the depth or duration of their sleep and contribute to dissatisfaction with sleep quality.

“This type of research is extraordinarily demanding. Sequential awakening studies require waking participants repeatedly over several nights and collecting detailed reports each time. This was only possible thanks to the dedication, perseverance and coordination of an exceptional team of researchers,” the researchers conclude.