Grow your brain...literally

Here's an incredible story about how focused mental activity can actually strengthen--as in physically improve--the brain. Nothing new, but still noteworthy. Excerpt:

How will our image of ourselves change as the wrinkled lump of gray meat in our skull becomes increasingly transparent to such exploratory methods? One recent discovery to confront is that the human brain can readily change its structure -- a phenomenon scientists call neuroplasticity. A few years ago, brain scans of London cabbies showed that the detailed mental maps they had built up in the course of navigating their city's complicated streets were apparent in their brains. Not only was the posterior hippocampus -- one area of the brain where spatial representations are stored -- larger in the drivers; the increase in size was proportional to the number of years they had been on the job.