%D 2003 %L eprints3321 %T Effect of healthy aging on the cholinergic modulation of the interaction between prefrontal cortex (PFC) activity and visual working memory (vWM) task difficulty %A Emiliano Ricciardi %A Pietro Pietrini %A Stanley I. Rapoport %A Mark B. Schapiro %A Maura L. Furey %I Elsevier %C New York, USA %B Neuroimage