The self is what we call a certain configuration of perceptions, and it is dependent on the natural world. The self is a collection of atoms, and the processes generated by that specific configuration. This means the self is the result of material.
When the self disconnects from the natural world, the self ceases to be. The configuration has been disrupted and the elements that made up the self are no longer collected and configured together under the name of, “The self.”
If a soul does exist, I do not consider it to be the self. I have no way of knowing whether or not a soul exists, but the self as I define it has no soul. The universe is a collection of atoms reacting with one another, our atoms included. I do not need the soul to define the self.