As of now, we cannot scientifically determine anything. We don't know if there is such a thing as a soul. And if there was one, we don't know if it ceases to exist, if it goes into another realm, or if it returns to the body of a newborn. Of another species. On another planet.
Measurable activity in the brain stops. That's all we know. We do not know if there is something greater that is independent from pure brain activity.
Even if you could record brain activity/personal experience at the moment of death and replay it, you could still not say anything about the experience AFTER death. Death is indeed the undiscover'd country from whose bourn no traveler returns.
So any debate is purely philosophical, there is no right or wrong.