Shania Twain, T. J. Lavin, Kate Douglass

Senior culture correspondent Anthony Mason talks with Shania Twain, singer-songwriter.

FIRST ON: T. J. Lavin, BMX cyclist and host of THE CHALLENGE 40: BATTLE OF THE ERAS.

CBS SATURDAY MORNINGco-host Dana Jacobson talks with Kate Douglass, Olympic medalist in swimming.