"Electroencephalographic Topography Measurements of Experienced Utility", emphasis on experienced. Pedroni A. et al, The Journal of Neuroscience, 20 July 2011, 31(29): 10474-10480. The response they measured unexpectedly increased disproportionately increasing reward, i.e. it did not demonstrate diminishing returns but rather the opposite.
A measure of the mismatch between decision and reward utility, and understanding its biological basis and how it differs between individuals, would be excellent for psychology as well.
Human cooperation in dynamic networks.
4 hours ago