We ‘Fall’ Asleep Suddenly, Not Gradually, New Study Shows
A recent study has revealed that the process of falling asleep is not a gradual one, but rather a sudden transition that occurs in the brain after reaching a tipping point. Researchers from Imperial College London (ICL) and the University of Surrey in the UK analyzed brain scans from thousands of volunteers to make this groundbreaking discovery.
The study, led by ICL neuroscientist Nir Grossman, found that there is a distinct change in electrical activity in the brain approximately 4.5 minutes before the onset of sleep. This abrupt shift in brain activity indicates that falling asleep is a bifurcation, rather than a gradual process, with a clear tipping point that can be predicted in real time.
By converting 47 features of brain activity captured by an electroencephalogram (EEG) into an abstract mathematical space, the research team was able to track changes in the brain as it transitions from wakefulness to sleep. The trajectory of these changes resembles a ball rolling down a steepening slope towards a fall, illustrating the sudden nature of falling asleep.

Using this model, the researchers were able to accurately predict the timing of sleep on subsequent nights with 95 percent accuracy, with a margin of error of 49 seconds. This level of precision in predicting sleep onset could have significant implications for understanding the sleep process and developing new treatments for sleep disorders.
Nir Grossman explained to New Scientist that the ability to track an individual’s brain activity and predict their proximity to falling asleep in real-time could revolutionize our approach to diagnosing and treating sleep disorders such as insomnia and excessive daytime sleepiness. Additionally, this knowledge could be utilized to develop technology that alerts drivers when they are becoming drowsy, enhancing road safety.
Furthermore, the insights gained from this research could lead to more accurate monitoring of anesthesia administration and serve as an indicator of overall brain health. The study was published in Nature Neuroscience, highlighting the significance of this new understanding of the sleep process.

