The work of Roni Horn, born in 1955, was on view in 2009 in a major retrospective at museums including Tate Modern London and the Whitney Museum of American Art in New York. She explores the subject of changing identities using a wide variety of media, including photography, sculpture, installation, drawing and text. The artist plays with similarities and differences in photographic portraits in particular, sounding out the ambiguity of various human facial expressions. The face becomes a projection screen for an internal dialogue for the viewer.