Alzheimer's disease is characterized by episodic memory impairments and brain deposition of the peptide amyloid-β (Aβ). However, not all older people with Aβ pathology exhibit memory deficits. Elman et al.examined whether brain hyperactivity, which has been observed in such individuals, might compensate for this pathology. Compared with old individuals with no Aβ deposits, cognitively normal older people with Aβ pathology showed increased activity in brain regions associated with detailed memory encoding, indicating that the increased activity may indeed be compensatory.