Alzheimer's doesn't have to be your brain's destiny, says neuroscientist and author of "Still Alice," Lisa Genova. She shares the latest science investigating the disease -- and some promising research on what each of us can do to build an Alzheimer's-resistant brain.

The Italian island of Sardinia has more than six times as many centenarians as the mainland and ten times as many as North America. Why? Learn more about super longevity as Pinker explains what it takes to live to 100 and beyond.