http://www.nytimes.com/2010/01/03/educa … -t.html?em

"Given all this, the question arises, can an old brain learn, and then remember what it learns? Put another way, is this a brain that should be in school?

As it happens, yes. While it’s tempting to focus on the flaws in older brains, that inducement overlooks how capable they’ve become. Over the past several years, scientists have looked deeper into how brains age and confirmed that they continue to develop through and beyond middle age.

Many longheld views, including the one that 40 percent of brain cells are lost, have been overturned. What is stuffed into your head may not have vanished but has simply been squirreled away in the folds of your neurons...

... Recently, researchers have found even more positive news. The brain, as it traverses middle age, gets better at recognizing the central idea, the big picture. If kept in good shape, the brain can continue to build pathways that help its owner recognize patterns and, as a consequence, see significance and even solutions much faster than a young person can...

... Teaching new facts should not be the focus of adult education, she says. Instead, continued brain development and a richer form of learning may require that you “bump up against people and ideas” that are different. In a history class, that might mean reading multiple viewpoints, and then prying open brain networks by reflecting on how what was learned has changed your view of the world...

... Such stretching is exactly what scientists say best keeps a brain in tune: get out of the comfort zone to push and nourish your brain. Do anything from learning a foreign language to taking a different route to work.

“As adults we have these well-trodden paths in our synapses,” Dr. Taylor says. “We have to crack the cognitive egg and scramble it up. And if you learn something this way, when you think of it again you’ll have an overlay of complexity you didn’t have before — and help your brain keep developing as well.”

Jack Mezirow, a professor emeritus at Columbia Teachers College, has proposed that adults learn best if presented with what he calls a “disorienting dilemma,” or something that “helps you critically reflect on the assumptions you’ve acquired.”"