Tarski wrote:2. It seems clear to me that what matters is the structure and meaning of those brain waves. Are they random? Do they indicate the existence of plans, hopes, fears, an inchoate mental language?
If we could graph the structure and meaning of brain waves on a Y axis, I would expect them to grow very gradually over a period of months. Even then, what is the most a fetus can comprehend? What kind of plans, hopes and fears can it possibly experience? It has no context until birth, and even then, babies are kind of stupid... it's kind of scary to define humans this way. Erring on the side of caution forces you to value potential for plans, hopes and fears.
I think if we're talking about humans we have to say a human-like nervous system is enough to value it as human. Sorry I'm not a human brainologist, but I know there are brain structures that other animals don't have. Cerebral cortex? I have to look it up. Anyway, once a human fetus has this we ought not abort it unless the mother's life is in grave danger. At that point, no free pass for rape and incest, in my opinion.
At the other end of the graph, I would think the brain waves drop off precipitously when a person dies -- kind of the opposite of gradual embryonic development.