There are many many things that scientists don't know or haven't discovered yet about the human body
I never know why people say stuff like this. We don't make conclusions based on things that aren't known, only things that are.
Science knows that if you mess with a brain, you mess with the personality of a person. Unquestionably. You can take away a person's ability to even recognise their own wife or children.
In the light of this knowledge, how does it make any sense at all that, when a brain is completely destroyed - either by decomposition or cremation - the personality emerges from the other side with every memory intact?
If it's because there's a soul, why doesn't the soul step up to fill in the blanks for a damaged brain?
The only sensible conclusion we can reach is that the brain is the seat of the personality - when it's gone, the personality is too.
Pretty stunning evidence would have to arise for the conclusion to change. And in spite of hundreds of years of solid research, not the tiniest scrap has been found.
It is remarkably silly to believe that people can talk to the dead - or even that the dead exist to be talked to.
And why do they never talk to scientists, by the way?