Can Quilting Prevent Memory Loss?

I just saw this article on the New Old Age blog.

"At the age of 78, Bob Branham, a retired computer software developer in Dallas, Tex., took up quilting. It wasn’t his idea, actually. He’d never dreamed of piecing together his own Amish diamond coverlet or rummaging around Jo-Ann Fabrics in search of calico prints. But then he enrolled in a trial sponsored by the National Institute on Aging to assess whether learning a new skill can help preserve cognitive function in old age. By random assignment, he landed in the quilting group.

... neuroscientists suspect that learning a challenging new skill — a new language, a new musical instrument — may be even more effective than mental games at keeping the brain sharp. And quilting is more complicated than it may seem..."

Maybe this explains why my grandmother (the galloping horse one) was still as sharp as ever when she died at 97. I wonder how helpful quilting is if you've already been doing it for years. Maybe if you continue to expand your repertoire of skills and keep experimenting, it has the same effect.