Furey, Maura L. and Ricciardi, Emiliano and Rapoport, Stanley I. and Schapiro, Mark B. and Pietrini, Pietro  Cholinergic Enhancement during Working Memory Eliminates Regional Cerebral Blood Flow (rCBF) Modulation Associated with Task Difficulty in Prefrontal Cortex.  In: 9th Annual Meeting of the Human Brain Mapping Organization, June 19-22, 2003, New York, USA         (2003)