I don't know if anyone else saw the CBS evening news on Wed. but the subject was the human brain. I think Katie said it was part of a week long series on the topic. The two main subtopics seemed to be brain atrophy due to aging and neuro. diseases such as Altzheimers and dementia. They reported on research that apparently shows that these problems could be slowed down or even reversed. The answer seems to be non other than exercise both for the body and the mind. They compared MRIs of seniors who exercise and those who did not. They used walking as their physical exercise and a computer software package that allowed them to exercise their brains in apparentlly fun and easy execises. The MRIs showed improvements and the seniors stated that they felt improvement as well. I don't remember the details of the study such as length of the study or the number of subjects. Maybe someone else did.