Teenager leaves spectacles on floor of San Francisco’s Museum of Modern Art as a prank, leading some to think they were an exhibit.

Marina Abramović's art pushes the boundary between audience and artist in pursuit of heightened consciousness and personal change. In her groundbreaking 2010 work, "The Artist Is Present," she simply sat in a chair facing her audience, for eight hours a day ... with powerfully moving results. Her boldest work may still be yet to come — it's taking the form of a sprawling art institute devoted to experimentation and simple acts done with mindful attention. "Nothing happens if you always do things the same way," she says. "My method is to do things I'm afraid of, the things I don't know, to go to territory that nobody's ever been."