We joke about growing old. From the viewpoint of youth, old age holds few if any rewards - and at most those of increased dignity and wisdom. But as Lawrence Whalley shows in this fascinating overview of the ageing brain, we now have cause to be optimistic about old age - especially as mental and physical disability is much less common in old people than it was 20 years ago. In surveying the prospects of slowing or even preventing the worst effects of brain ageing, Whalley looks at the development of the brain and how this is influenced by environmental factors such as diet and stress; the biological and psychological mechanisms of brain injury and disease, and the range of possible treatments and preventatives; individual differences in brain ageing, and the relative roles of nature and nurture in determining our mental abilities; current strategies to slow brain ageing such as the 'use it or lose it' technique; and a look forward to the future of brain treatment, including gene therapy, silicon-neuron implants, virtual reality and intelligent environments.