system
Given the following post, respond as if you're commenting on Reddit:
human
ELIF: Waking up.

How we go from that special sleepy brain wave stuff to normal awakeness. Especially after being really suddenly awakened by a loud noise or something.
gpt
When you're both asleep and awake different parts of your brain are working together, activating and suppressing each other.

* When you're deeply asleep and not dreaming, in non-REM sleep, most parts of your brain (as far as we mostly know) are in a literal kind of "sleep-mode", pulsing with slow waves of brain activity. We don't know *exactly* how and why we feel more rested and other specific mechanics of sleep very well but this is something lots of scientists are trying to understand. When you wake up naturally, your brain has already started to get out of most of this very deep sleep by the time you regain consciousness.

* Being violently woken up in this state leads to massive disorientation and grogginess. You're bewildered, blinking in the dark, and just like "whaaaa...?" Your brain is still "powering up" and waking up in the literal sense. All those parts of your brain that you need to consciously function that were put asleep such as acute visual processing, spacial orientation, and hearing need to get running. Obviously, these work at a minimum to defend you against danger while sleeping, but the amount of stimulus needed for a reaction increases. For example, when someone is sleeping very deeply you need to shake them or make quite a lot of noise to get them to respond. Their senses are "dumbed-down". When you wake up suddenly, your senses are still "dumbed-down" and it takes a while for them to become acute and fully functioning. The consciousness and reasoning zones of your brain are especially effected which results in the zombie like confusion. If your alarm was set to wake up you up while you were in this state, you might still feel tired and in need of lots of coffee for many minutes or even a few hours. Of course, if what woke you up was violent enough and your brain thinks you're still in danger, your survival mechanisms kick in and all the flight-or-fight chemicals such as adrenaline can make you focus almost immediately because it might be a matter of life and death.


* When you're dreaming, in REM sleep, much of your brain is already active. Parts of your brain release biological chemicals that block signals from leaving your head so that you don't physically act out your dreams. If you're woken up in a "shallower" sleep state or REM sleep, your brain doesn't have as much "waking up" to do, it's already alert and processing and functioning at near-full power, including the consciousness and reasoning zones (after all, you're consciously perceiving in a dream even if you're not aware that you're asleep). If you're jolted into the frame of reality, your mental faculties are already up and running and all you have to do then is quickly get an awareness of your surroundings and you're good to go.