Finding healthy, satisfying mental stimulation is one key to establishing a cognitive reserve, an essential component in staving off cognitive decline. But, as Harvard neurologist Dr. Alvaro Pascual-Leone describes, playing the same computer game over and over won't help. It's important to "cross-train" the brain with a variety of fun, challenging mental activities. Dr. Pascual-Leone is the faculty editor for the Harvard Health Publishing special health report A Guide to Cognitive Fitness. Click this link to learn more.