Conclusion: “The Aging Brain: Through Many Ages” explores ways brains fail---and why some don't---in later life. The hour also surveys encouraging developments in treating stroke patients and people with Alzheimer's. Encouraging to neuroscientists as well is evidence that “the brain is not a fixed machine for which there are no replacement parts,” says Dennis Selcoe of the Harvard Medical School. One key: exercise, both mental and physical. Another, as nonogenarian poet Stanley Kunitz puts it: “Desire! Desire! Desire!”
“The Adult Brain: To Think by Feeling” (Part 4) explores the relationship between reason and emotion. “We are not thinking machines,” says Antonio Damasio of the University of Iowa. “We are feeling machines that think.” But one man profiled was left unfeeling by a stroke (“It's as if I lost my best friend,” says his wife) while another, an auto-accident victim with post-traumatic stress disorder, is overcome by terror (“It's not a memory,” says Harvard's Roger K. Pitman, “it's a reexperiencing situation”). The hour also looks at neurological reasons for depression---“the ultimate isolation,” says psychologist Lauren Slater.
“The Teenage Brain: A World of Their Own” (Part 3) focuses on the development of the prefrontal cortex, the part of the brain responsible for judgment and reason. “Adolescence is a time of great biological tumult,” says Daniel Weinberger of the National Institute of Mental Health, “and the frontal lobe is fighting to adapt to the environment and deal with all these inner instinctual urges.” Fighting against it (and afflicting many teens): schizophrenia and addiction, which are explored in case studies. Blair Brown narrates.
“The Child's Brain: Syllable from Sound” (Part 2) explores how children master language. “Nearly all children learn to speak as easily as a bird learns to sing,” says narrator Blair Brown. For some seen here, though, brain abnormalities can impede progress. The hour also looks at how youngsters learn to read, which is more complicated (Brown calls it a “high-wire balancing act”), and studies the case of a boy with dyslexia.
“The Baby's Brain” (Part 1 of five) explores brain development at the beginning of life. “In response to the demands of life, the baby's brain sculpts itself,” says narrator Blair Brown. In the womb, neurons are formed and trillions of connections among them are made (“more connections,” says Brown, “than there are stars in the sky”). The hour also follows a baby born almost three months prematurely to see consequences of the interruption of prenatal development and how doctors are dealing with it.