I’m curious what mechanism is at work here.
Edit: Thanks for the responses. I get it now. Obviously I am still enjoying the discussion RE: the finer points like memory, etc.
In: Biology
How general anesthesia works is not well understood.
Sleep is very different. Your brain is like a large office building: at night, the lights may mostly be off but the power is still on, there are still security guards, some people working through the night, maintenance crews, and so on. That’s sleep. Sleep is not your brain turning off, sleep is something your brain actively does. Importantly, while you are sleeping your brain still has the capacity to wake back up whenever it wants to, e.g. in response to external stimuli, including pain. You’ll also do things like shift position to stay comfortable, and so on.
Unconsciousness and general anesthesia are more like the building has been evacuated and the power is out. In that state, the brain can’t wake itself back up whenever it wants, and it doesn’t do things like shift your body around. Pain signals can reach the brain, but it’s like a burglar alarm going off when there’s nobody there to hear it. The physical/emotional sensation of pain (i.e. “hurting”) is something your brain does in response to pain signals; if your brain is mostly shut down, then pain can’t hurt.
All of which is why unconsciousness is so dangerous, and why general anesthesia is only done under the close supervision of an anesthesiologist.
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