Our recent fMRI study of cooperation and defection in a coordination game scenario is to feature in an ESRC web article shortly (watch this space!).
A link to the original article in the Journal of Neuroscience, Psychology and Economics is here http://psycnet.apa.org/journals/npe/5/1/1/ as well as being available on the Lincoln Repository. The work was carried out in collaboration with famous Italian philsopher Francesco Guala (University of Milan).