Drugs that increase brain levels of the neurotransmitter acetylcholine can enhance cognitive functioning. Cholinergic enhancers are, in fact, the most used pharmacological therapy for patients with Alzheimer’s disease. In young adults asked to remember faces, these drugs increase activity in brain areas specific to visual processing and decrease activity in the prefrontal cortex, where information is maintained and manipulated. The activated brain regions are somewhat different in older adults. Freo et al. (p. 2061) examined whether the brains of young and old adults would respond differently to physostigmine, a cholinergic-enhancing drug, during an exercise involving short-term memory of faces. Without physostigmine, task-related activation occurred in different prefrontal subregions in old and young subjects. Physostigmine reduced activation in these age-specific areas, enhanced activity in visual cortical areas, and improved task performance. Apparently, structural and functional changes during aging can shape the way a drug affects the brain.