Ah, this age old question. The most probable scenario is that once you kick the bucket, that's it. The brain, the organ which is responsible for all mental phenomena, decays along with the rest of our body. I like the idea that maybe there is some aspect of us, a soul if you will, carries on after our death (who doesn't really), or maybe our minds are of a fundamentally different nature than the physical and exists on a different plane. But that's just wishful thinking. Most philosophers (and neurologists) have long abandoned such a dualistic conception as far as I know.