The document discusses mental fitness and its importance. It summarizes research from several scientists and doctors such as Dr. Richard Davidson, Dr. Candace Pert, and Dr. Elmer Green. Their research showed that the mind can affect the body, positive emotions can shift brain activation to the left side, and meditation/imagery can control physiological functions. Exercising and challenging the mind through activities, social interaction, meditation, and a healthy lifestyle can promote mental fitness and prevent cognitive decline.