That's interesting. It's one of a few studies that supports a mental functioning, if it's lifelong and of specific type, prevents nerve cell degeneration and dying. If the theory that mind inactivity causes dementia is true, it will revolutionise it's prevention with lifelong adult training. AI could help immensely in this field keeping the community mentally occupied. I am waiting for a solid study measuring that a stress free group (either due to personal or professional status) beats all the stressful ones. We know it happens but it's nice to have evidence. Which group has obviously less stress today?