The effects of aging on cognition are not uniform. Rather, certain aspects of attention and memory are adversely affected by aging, whereas other cognitive domains are relatively preserved, and others even show positive age-related changes. Several overlapping cognitive theories have been advanced to explain these aging-related patterns, but none has prevailed yet. Cognitive neuroscience studies have focused on structural and functional changes in prefrontal and medial temporal regions, and have underscored the importance of declines in glucose metabolism and the availability of critical neurotransmitters (eg, dopamine and acetylcholine). These and related brain changes in aging can be influenced (negatively or positively) by several factors, including diet, exercise, and stress. We discuss several challenges in interpreting the present literature and progress in developing interventions for promoting the preservation and improvement of cognition in older adults.