Doctors may eventually be able to diagnose "preclinical" Alzheimer's in patients who have abnormal brain scans but who aren't yet showing behavioral symptoms of the disease. iStockphoto hide caption

itoggle caption iStockphoto

University of Florida researcher Jennifer Stamps administers the peanut butter sniff test to a volunteer. Jesse S. Jones/University of Florida hide caption

itoggle caption Jesse S. Jones/University of Florida

The underlying biology of age-related memory glitches — in old mice and old people — is different from what happens with Alzheimer's, recent research suggests. Anthony Bradshaw/iStockphoto.com hide caption

itoggle caption Anthony Bradshaw/iStockphoto.com