Recently, I read the book, Carved in Sand: When Attention Fail and Memory Fades in Midlife. Cathryn Jakobson Ramin, Harper, New York, 2007, which is a very good book.  The author is an investigative jounalist who improved her mental functioning with various interventions, including digital brain exercises, meditation, drugs, and hormones.  After 10 interventions, her forgetfulness decreased and also gained more energy.  Environmental effects including diet, intoxication, polution, and genetic volnerability are well covered.  She delved into the research of brain trauma, forgetfulness and dementia.  She included profiles of several people who had experienced mental decline starting at middle age.  Like me, the author has prosopagnosia and short working memory so I could relate to her very well.  I enjoyed this book very much as I am very interested in biology and psychology.