In my view our minds are basically an electrical machine. This means there is energy. Energy is not created nor destroyed. It does change forms but still exists. Now what's to say that our energy doesn't take on another form? Also, what's to say that there isn't a "force" (for lack of a better term) that somehow guides our energy into it's next form, based on the actions of this form? Be that Karma, God, a Deity...............Depends on your belief. Even at the point that there may not be a "force" to do this, where does this energy, which is what supported the brain go after the flesh has worn out?