Mary Barnes exhibition exposes art's dirty underside

Space Studios in east London are holding a major retrospective, starting next week, of the work of Mary Barnes. Enticingly, the publicity informs us that in 1965 Barnes "produced her first artwork – a pair of black breasts painted on the wall of her room in her own shit". To be fair, Barnes was not exactly in her right mind at the time: she was the first resident of an experimental therapeutic community set up by the radical psychiatrist RD Laing. The show, covering more than 40 years of work, looks interesting, although it's a relief there's no gift shop.