It so happens that as a researcher—I'm a cognitive neuroscientist—this is the kind of question I'm working on. We have this notion of cognitive reserve, or brain reserve, which we can nurture throughout our life. All of this should not start at 65. We should start early with the kind of physical activity that has a direct relationship with brain reserve. CIHR is funding studies by Dr. Louis Bherer, who's showing that physical exercise has a direct impact of the oxygenation of the brain. You have a better reserve to face problems later in life. Having some intellectual activities provides the same benefit. In some countries, you have areas where people do this systematically. Recently I had the chance to be in Shanghai. There are many centres within the city where Chinese people can go to play mahjong, do tai chi, and exercise. They prepare their brains to be stronger.
Mental health is not only cognition. It is also depression and so on. One thing that is important at that point is social isolation. We have to make sure we understand the social insertion and network determinants of mental health and provide evidence to support decisions on the best way to provide these environments where older people will maintain their social participation in our society. That's how you feel happy about living.