As the technological environment speeds up to a maddening degree, Klingberg, a professor of developmental cognitive neuroscience at Sweden's Karolinska Institute, warns that the huge burden of information overload and multitasking can exceed the limits of our slowly evolving stone-age brain. Using data showing the subtle increase in IQ scores during the last century and its link to educational improvements, Klingberg notes a gap between the rapidity of electronic high-tech devices and the brain's relatively slower capacity to process information, leading to memory malfunctions. The text can be somewhat academic, but the amount of scientific fact translated to something the reader can use is still sizable, including keen writing on the impact on working memory of problem solving, meditation, computer games, caffeine and the existence of attention deficit disorder. Klingberg also reviews the evidence that mental exercise can increase the capacity of working memory. A highly sane look at the increasingly insane demands of the information age, this book discusses with precision a subject worthy of attention. B&w illus. (Nov.)