Fair enough, so the answer to your from before then is: I do not know if the "begining of brain waves or even brain cells indicates the beginning of a person", but this is the begining of a process that will make a brain, that will understand that it is alive, and this is when tissue becomes a person.
2. And about people in a deep coma, who recover -- do they cease to be persons, then become persons again?
You see this is a difficult one to answer because "coma" is a very generalized term and only one of a few different responses of the CNS to injury, but according to my criteria, I suppose one could make that argument.
People have self-directed and interrelational minds, emotions, wills, and as you say, knowledge of self, also of relation and responsibility to other beings. Science has no way of proving when these begin for a person any more than it has a way of proving what these phenemena are for a person, or when a person begins.
You're right science cannot prove the exact magical moment, but it can show that without a brain (1) you will not live and (2) you cannot know you're alive. Science can prove when brain development begins.
4,. I didn't ask you what you think.
Well I cannot answer your original question as I don't believe we're "assigned". It'd be like if I asked you something strange like, "What if you killed someone in a past life?" How would you answer? You cannot unless you believe in a past life.
5. If what you say is true, it's funny how different things exist for different people... and how more and more suddenly exists, as science goes on.
I don't disagree
Sounds like New Age "mind science" that you believe, by this post, not science and not a reverence for human life.
Not true at all. I just posit that there are certain necessary conditions needed in order for tissue to become a person. I am sorry that this bothers you.
Demonstrate if you will, that tissue ever becomes a person... and not that a person may exist, both before and after that tissue functions.
Your body is you, but... are you your body? Can you prove you do not exist before or after any particular cells of your body perform in any particular way?