About 11% of Americans over the age of 65 are diagnosed with Alzheimer's disease and related dementia. For others, the changes in memory we experience as we age are normal.
The big picture: Rather than passively declining, the brain adapts and changes as humans age. Researchers want to understand how our ability to remember changes with age in hopes of improving it, and of treating and preventing Alzheimer's disease and dementia. Those diseases are "superimposed on an aging brain," says Carol Barnes, who studies healthy brain aging at the University of Arizona.