Though it may depend on the type of artwork on display?
From todays Guardian…
Monday January 9, 2006
Visiting an art gallery may be the perfect antidote to stress, according to research. Analysis of 28 City high flyers who spent their lunch break viewing art found their stress levels fell by 45% after 40 minutes at the Guildhall art gallery in London.
Saliva samples contained 32% less cortisol stress hormone than before the visit. Normally, it would take about five hours for cortisol concentrations to fall this far. Angela Clow, from the University of Westminster, said: “A short break at lunchtime, in a beautiful and calming environment, can help restore normative levels of cortisol.”