• How do we measure changes in the brain?

• What major changes occur in neurons? How does the ability of neurons to communicate with each other change with age? What are the psychological effects of changes in the brain?

• What major changes occur in the autonomic nervous system?


orge is an active 83-year-old former factory worker who lives with his wife, Olivia, in a crowded apartment in Los Angeles. Over the past few years, Jorge has had increasing difficulty handling the heat of southern California summers. Olivia has noticed that Jorge takes more naps during the day and sleeps poorly at night. Jorge and Olivia wonder whether there is something wrong with him.

Our brains are the most complex structures yet discovered in the universe. Everything that makes us

individuals is housed in the brain, and we are only now beginning to unlock its mysteries. The major challenge is that observing age-related changes in the brain is difficult. Usually we must rely on indi­rect evidence such as memory problems. However, advances in brain-imaging techniques are making it easier to watch ongoing brain activity in people of different ages.

In this section, we consider the age-related changes that occur in the central nervous system (the brain and spinal cord) and the autonomic nervous system (nerves in the rest of the body). Understanding nor­mative changes in the central nervous system sets the stage for understanding diseases such as Alzheimer’s disease, discussed in Chapter 4, as well as many of the cognitive changes discussed in Chapters 2, 6, 7, and 8. Jorge’s experiences are related to changes in the autonomic nervous system; we’ll discover whether Jorge’s problems are normative.