Khaberni - When you wake up in the morning, you may feel like your mind is beginning to activate with the sound of the alarm, although you may feel drowsy for some time, but the process that the brain goes through to wake up is a gradual and coordinated process, so how exactly does that happen?
Rachel Rowe, a professor of integrative physiology at the University of Colorado Boulder, according to the Life Science website, says: "Wakefulness means that the brain is in a state that supports awareness, movement, and thinking. Unlike sleep, where brain waves are slow and synchronized, wakefulness is characterized by faster and more flexible activity, allowing us to respond to the world around us," according to the Life Science website.
However, there isn't a single moment when the brain transitions from sleep to wakefulness, says Aurelie Stephan, a sleep researcher at the University of Lausanne in Switzerland.
Research has shown that subcortical regions in the brain - a collection of neural formations located beneath the cerebral cortex - are responsible for waking us up.
Row explained that the reticular activating system (RAS) initially acts as a "start switch," sending signals to activate the thalamus, a structure that relays sensory information to other parts of the brain, then to the cerebral cortex, which is the brain's outer, wrinkled layer.
In a study conducted in 2025, Stephan and her colleagues found that the brain executes a distinctive pattern of activity upon waking. When participants woke up from non-rapid eye movement sleep, which includes various stages ranging from light to deep sleep, their brain activity initially showed a short burst of slower, sleep-like waves, followed by faster waves associated with wakefulness.
When participants woke up from rapid eye movement sleep - a sleep phase characterized by vivid dreams and rapid eye movements - their brain waves immediately shifted to faster activity.
Overall, regardless of the sleep stage of the participants, it seemed that their brain activity began in the anterior and central regions of the brain and moved to the back of the brain upon waking, according to the researchers.
Once we wake up, our brains need sufficient time to reach their full cognitive potential.
Stephan says this period, called sleep inertia, can last from 15 to 30 minutes, or even up to an hour. Researchers do not know the reason for this morning inertia, but our wake-up time plays an important role in how we feel, and giving up the alarm might help us.
Stephan explained: "When your brain wakes up [naturally], it will send a signal at a logical moment" to end your sleep, and there are many areas that take both internal and external signals into account, and discuss among themselves when to transition to different sleep stages, and also, eventually, when to wake you up automatically.
Our wakefulness system listens to these internal and external inputs, and establishes cycles in which we are more alert every 50 seconds. Our level of alertness fluctuates during these periods, increasing and decreasing repeatedly.
Stephan said: "During the processing phase... it's difficult to wake up. But when the cycle weakens, our sleep becomes more fragile and it's easier to wake up."
And she added: "Therefore, during this fifty-second period, we go through a period of sleep continuity and a period of its weakening."
That is why she always advises her friends to wake up at the same time, without using an alarm.
The right moment that does not exceed fifty seconds
She said: "Your brain will wait for the right moment that does not exceed fifty seconds, and you will feel less drowsy when waking up. If you have an alarm, it will be somewhat random, potentially waking you at the worst possible moment, and then you will suffer from severe sleep inertia."
Nevertheless, much of what we know about waking up remains a mystery. Scientists are still unsure why we feel refreshed after getting the same amount of sleep on one day, while we don't feel it the next day. Some research has indicated that diet and sleep duration can affect morning alertness, or how the brain transitions from wakefulness to sleep.
