Deep sleep is the key to sudden insights

A group of scientists asked 90 volunteers to complete a simple but slightly confusing task of tracking dots on a screen. The task was simple, but the instructions specifically omitted a trick that could greatly simplify the execution.

After several rounds, participants were offered a 20-minute afternoon nap, during which their brain activity was monitored using electroencephalography (EEG). The results were impressive: more than 70% of people suddenly “guessed” the hidden clue after sleep and solved the problem easier.

It is especially surprising that 85% of the participants had an epiphany in those who plunged into a deeper sleep phase — the so—called N2. While among those who did not sleep or remained in a light stage of sleep, this indicator was noticeably lower.

The researchers noted that it’s not just the rest itself that is important, but deep sleep, which seems to promote special changes in the brain. EEG analysis has shown a link between the steepness of the spectral slope — a special indicator of brain activity — and the occurrence of insights.

One of the co-authors, Nicholas Schack, shared: “It’s exciting that just a short nap helps people see new connections and solutions that previously seemed inaccessible. Now our task is to understand why this is happening.”

Many of us have already felt how an important idea comes after a nap. Now we have not only subjective feelings, but also scientific data explaining this phenomenon.

The study not only confirms the popular saying “morning is more complicated than evening,” but also opens the way to a deeper understanding of how the brain works during sleep and how sleep can be used to increase creativity and solve complex problems.