A great deal of the mental ability lost with age can be attributed to lack of use, (just like our physical selves). Our mental function depends on neural highways, which like neglected roads eventually become unavailable for use. But we can continue to learn and grow new connections (or highways) in our brains throughout our lives. Any type of learning can provide this stimulus: courses, conversations with friends, learning a language or even word games can keep us mentally sharp. By keeping physically and mentally active, we are two times less likely to suffer from dementia.