Some people have studied it... Allan Hobson, a Harvard professor for one. I read his book called "The Chemistry of human consciousness" by him, that explained how brain states work. The brain goes from waking to sleeping in very particular ways and depend on critical balances of chemistry to make it work... his studies have explained how manic-depression is an imbalance that creates dream-like hallucinations in people who are awake, and vice versa how drug therapies have worked, and for that matter caffiene, in the brain chemistry balance business.
When you think of it, a coma is not brain damage, but brain *state* damage. What has me convinced that we dont really understand comas well is this nonsense of calling people 'brain dead' when a lot of it has to do with their brain state and *not* their brain capability. It's like a computer that has failed to reboot properly, and then imagining the CPU is missing because it doesnt reboot. Nonsense.
"I wonder if these people have some unique genes that enable some brain regeneration or brain remapping that wouldn't normally occur in someone else."
Both have happened. Whether that is what is happening here.
These miracles are telling us to be humble - we don't know how people are put into these states and we don't know how to get them out of these states.
And it is telling us that God decides when we should die and His time is not the same as our time.
The same with the healing He gives.