Picard is brought into a an existing character who has a wife, best friend, hobbies, and an occupation. Was he placed in someone's existing story from Kataan? Or did the Kataan people just build a generic (or common) person as a framework for the experience they wanted to impart on whomever the probe found?

Eventually he decides to have children with his wife. Are they the actual children of the person whose life he assumed? Or are they just a fabrication of the simulation extrapolating Picard's personality and the woman he was paired with?