"Most of us would like to be smarter," asserts Restak (The Brain, companion to PBS's series by the same name), neuropsychiatrist and clinical professor of neurology at George Washington University Medical Center. Restak claims that improving cognition is the answer. In accessible science-teacher style, Restak delineates the brain's attributes, from its weight (three pounds) to the number of nerve cells (100 billion) and its infinity of synapses, explaining what aids communication, informs memory and so forth.