One of the values of art lies in its ability to question culturally dominant modes of representation. Art can challenge powerful categories like identity, production and desire. Whereas a media like advertising is supposed to tell us what we want, art – or at least some of it – is supposed to ask us what we want. It can stimulate an encounter with our experience of representations as such and highlight the way in which the realities we take for granted are constructed ones. Art might be seen as a culture's way of showing how its own systems of representation function. This role is made more complex by the fact that works of art can also do more than simply show. Darian Leader

Mona Hatoum, Suspended , 2011
High pressure laminate, metal chains, dimensions variable, Photo: Hugo Glendinning, Courtesy of the Artist and White Cube

Braco Dimitrijevic, 'Resurrection of Alchemists' video 2 mins, 2006 Courtesy the artist and Handel Street Projects