Norman Bryson discussed perceptualism in terms of optical truth, as opposed to constructivist interpretations that take into account the social values of any given era's zeitgeist.
Sometimes, the role of observer is obscured as members of the public may unwittingly or unknowingly be participants in the creation of the artwork itself.
In the late 20th century, visual artists such as Robert Smithson, with his massive land-based creation entitled Spiral Jetty, began to break down barriers between art medium and subjective interpretation.
Jack Chambers used "sense combinations [to] complement one another to enrich perception"[2] in paintings such as 401 Towards London No.
A new generation of artists have continued stretching definitions and boundaries between performance, intent and meaning, such as Karen Finley, whose controversial performances were criticized by a U.S. senator, Joey Skaggs, who creates artificial news stories that are often reprinted by major media outlets, and Paul Rebhan who charges a fee for his friendship, smuggles his own paintings into museums, and hosts dating events where no one is allowed to speak.