Brain Activity Patterns Reveal Why Waking Up from Sleep Can Be So Difficult

Brain science reveals why alarm clock can be such a struggle

By Katie Kavanagh & Nature Magazine

How does your brain wake up sleep? A study of more than 1,000 sleep excitations revealed precisely how the brain withdraws during the transition to vigilance – a discovery that could help manage sleep inertia, the genus that many people feel when they hit the repetition button.

The recordings of people when they woke up from the sleep -laden sleep phase showed that the first regions of the brain to awaken are those associated with executive function and decision -making, located at the front of the head. A wave of awakening then spreads to the rear, ending with an area associated with vision.

The results could change our way of waking up, explains Rachel Rowe, neuroscientist at the University of Colorado Boulder, which was not involved in the work. The results underline that “falling asleep and woken up are not simply inverted processes, but really wakeing up this wave of orderly activation that moves from front to the back of the brain”, while the release seems to be less linear and more progressive.

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The study was published today in Current biology.

Sleeping of the sleeping brain

The awakened brain shows a characteristic electrical activity scheme, recorded by sensors on the scalp – it looks like a shredded line composed of small peaks and closely wrapped valleys. Although the motif seems similar during the rapid sleep of the eyes (REM), when lively dreams occur, this step presents a lack of movement of the skeletal muscles. The peaks are larger during most of the stages of sleep not Rem, which ranges from light to very deep sleep.

Scientists already knew that the “awake” signature occurs at different times in different regions of the brain, but current imaging techniques have not made it possible to explore these models in a specific time.

To refine the understanding of awakening, Francesca Siclari, neuroscientist of the Dutch institute for the neuroscience of Amsterdam, and his colleagues studied 20 people while they woke up sleeping. The brain activity of each participant was recorded using 256 sensors on their hair leathers. Some awakenings were spontaneous; In other cases, the participants were awakened by an alarm.

The sensors allowed scientists to analyze brain activity in a second time period to second. Using mathematical algorithms and modeling, the team then rebuilt where this activity occurs on the surface of the brain.

Snooze

The researchers found that the awakened neural signature spreads from front to back when a person flows from Rem. However, during sleep not Rem, the motif first appears to a central “hotspot” deeply in the brain, then progresses through the same motif of the back observed during paradoxical sleep. This variation could explain why the participants said they felt less asleep when sleeping on sleep no Rem than paradoxical sleep, says Rowe, although it is not clear why this model would have this effect.

“The surprise is how much [this pattern] Was through each awakening and also how it was linked to subjective measures ”, including the sleep stadium and the awakening method, explains Siclari.

Siclari hopes that this research can be used to combat sleep disorders such as insomnia. “Knowing exactly how brain activity is characterized when a normal awakening [means] We can better compare it to these abnormal awakenings, ”she says. Rowe agrees that the results could help people who fight with sleep. “The way a person wakes up can be altered, as opposed to the way they fall asleep,” she said.

This article is reproduced with permission and was first publication July 17, 2025.