With all the hype about keeping your brain fit, what do people believe you have to do to accomplish this? To find out, ask some people of different ages these questions: What happens
to the brain as we grow older? What do you think causes these changes? What do you think you can do to make sure that the brain stays fit as you grow older? Compile the results from
your interviews and compare them with what you discover in this chapter. To what extent do people’s beliefs correspond to the scientific evidence? In which areas are they completely off base?
 |
function as they affect cognitive performance in older adults. For example, studies using this approach have found that younger adults’ brains show unilateral activation (i. e., activation in only one hemisphere of the brain) when they perform specific cognitive tasks whereas older adults’ brains tend to show increased activation in both brain hemispheres when performing the same tasks (see Cabeza, 2002). As we will discuss later, this differential activation in younger and older adult brains may provide neurological evidence that older adults undergo compensatory changes that allow them to adapt to the inevitable decline of specific areas of the brain.
Overall, these neuroscientific approaches to studying cognitive aging promote theoretical development in the field of adulthood in several ways. First, theories can be further tested using these approaches. For instance, the idea that we can selectively direct our attention to specific characteristics of our environment can be further validated by examining how age-related changes in performance are associated with both functional and structural brain variables. In other words, we can explain how the brain influences performance. This also could be investigated in the maturing brains of adolescents and children. Second, research methods that focus on the age-related changes in the architecture and functioning of the brain can help to explain why certain cognitive functions, such as well-practiced tasks, vocabulary, and wisdom, can be preserved
into old age while other functions, such as processing speed, decline rapidly as people age.
Neuroscientific methods, however, have limitations (Cabeza, 2004). For instance, documenting activities in different brain regions does not necessarily imply that different psychological processes are involved (e. g., sensory motor functioning, vision, and hearing may be similar cognitive processes but may engage different regions of the brain). Nevertheless, advances in the field of neuroscience have had a major impact on our understanding of cognitive aging because they have revealed new findings that psychological theories have to account for and be consistent with.
Before we explore some of the scientific research on age-related changes in the brain, complete the Discovering Development exercise. Compare your findings with the evidence described in the text that follows. What similarities and differences are revealed?
Concept Checks
1. How might developmental forces interact in the context of understanding brain changes as we grow older?
2. What is the basic premise of the neuropsychological approach to neuroscience?
3. What are the limitations of the correlational approach to neuroscience?
4. What is the major advantage of the activation imaging approach?