Figure 1.1. Magnetic resonance images of the aging brains of living subjects that show
different degrees of atrophy of the hippocampal regions known to be involved in memory
processes. The images at the top and on the bottom left are from a 73-year-old person
with Alzheimer's disease, while that on the bottom right is from an 86-year-old athlete.
(Illustration courtesy of Thomas Budinger, Lawrence Berkeley National Laboratory.)