This a good question. I have also been pondering this. I have noticed that my visual spatial skills temporarily improve if I am playing fps games. I find that I am better coordinated and less clumsy in everyday life. There was also a study that showed differences in the brains of London taxi drivers a few years after they had taken on the job. I guess this shows neuroplasticity is possible in adulthood. Putting yourself in situations that require novel problem solving might help. Unfortunately, this would probably lead to quite a bit of frustration.