In the play “Incognito,” four actors play 21 different roles, without so much as a set change or a new costume. In fact, they never even leave the stage.

The Gamm Theatre in Pawtucket is giving “Incognito,” by British playwright Nick Payne, its New England premiere. The Gamm’s Artistic Director Tony Estrella and actress Casey Seymour Kim join Rhode Island Public Radio’s Elisabeth Harrison in the studio to talk about the play, and what it says about the brain, memory and identity.

