Expectation enhances the regional brain metabolic and the reinforcing effects of stimulants in cocaine abusers. - Volkow,ND.; Wang,GJ.; Ma,Y.; Fowler,JS.; Zhu,W.; Maynard,L.; Telang,F.; Vaska,P.; Ding,YS.; Wong,C.; Swanson,JM. (J Neurosci, 2003)