Our knowledge about the process of aging has continued to evolve as the methods used to study this process become more sophisticated. As more becomes known about the diagnostic criteria for dementia, the population of subjects taking part in aging studies has become more carefully screened minimizing the role of dementia as a confounding variable. Furthermore, advances in imaging techniques now allow us to view the anatomy of the brain in vivo better than any time in the past paving the way for longitudinal studies of the brain. It should not be surprising given the changes seen in studies of aging that our conventional wisdom of the aging process is being called into question.