As we grow older, of course, our bodies become less and less capable --- and less reliable --- when it comes to doing all the things we used to do. But as our guest reports on ST today, one of the very exciting findings in recent medical research is that the human brain can actually grow (and get stronger) over time --- and a bigger brain means better memory, increased creativity, sharper concentration skills, and a more rapid speed of learning. Our guest is Dr. Majid Fotuhi, the internationally recognized neurologist, science writer, and medical commentator. (His television series, Fight Alzheimer's Early, has aired on PBS stations nationwide.) Dr. Fotuhi is also the co-author of a new book, "Boost Your Brain: The New Art and Science Behind Enhanced Brain Performance." In this volume, Dr. Fotuhi (who was at Johns Hopkins and Harvard Medical School for more than two decades) guides us through the innovative brain fitness program that he has developed for his patients at the NeurExpand Brain Center, an institute dedicated to helping people quickly sharpen their brain performance. Detailed and useful information is given, for example, on how to spur new brain-cell growth, which foods help to build new synapses, what creates brain reserve, why one common sleep disorder can reduce one's memory by as much as 18 percent, and so forth.