Consciousness is the product of electrochemical signalling in the neurons of your brain. So when the brain stops functioning fully, your consciousness, or to a broader aspect your mind ceases to exist with its unique individualistic qualities. It's like the soothing flow of water. It is only water as long as its internal realm of two atoms of hydrogen and one atom of oxygen, remains intact. If you break that structure which we call H20, it ceases to be water. Likewise a soul remains a soul, as longs as its neural structures remain intact. If you mess with those structure, then the entire personality of the soul may get radically altered. So, to think even further, if those neural structures inside your head stop working, then the soul ceases to exist forever. So, as long as you have a functional brain, you exist, and the moment that brain dies you die.