• What is processing speed? What age differences are found?

• What are the processing resources that underlie information processing?

• What is inhibition loss? When are age differences found?

• What are attentional resources? Under what conditions are age differences observed?

• How do automatic and effortful processes differ? In what situations are age differences present?


hloe was gazing out the window during her his­tory class. The teacher sternly told her to “Pay attention!” As the teacher came to the question-and – answer period of class, she immediately called on Chloe. Of course, Chloe did not know the answer. “I expect you to pay better attention to class!” was the teacher’s next remark.

All of us probably have had similar experiences. Someone asks us a question and we continue to stare off into space. We are driving along a long, boring stretch of interstate highway and suddenly realize we have gone 20 miles with no awareness at all of any­thing that we saw along the way. The examples are quite varied, but the outcome is the same: Somehow we come to realize that lots of information was available to us that we never processed. In short, we simply did not pay attention. Let us look at the role attention plays in theories of cognitive aging.

Researchers typically look at how we regulate or control attention. Broadly defined, attentional con­trol is linked to frontal lobe processes discussed in Chapter 2 and involves working memory, inhibitory control, and task switching (Luszcz & Lane, 2008). These components are typically treated as cognitive primitives or foundations of cognitive processing that undergo change as we grow older. In fact, leading theories of cognitive aging involve these processes.

Speed of Processing

Speed of processing reflects the outcomes of sen­sory memory and attention, in that researchers are examining relatively early aspects of information processing. In fact, some of the ways in which speed is measured, such as how fast you can react to a stimulus, are indices of sensory memory func­tioning. Thus, speed of processing can be viewed to some extent as a reflection of how quickly and efficiently these early steps in information processing are completed.

Researchers previously adopted the notion that a decline in speed of processing explains age-related changes in cognitive functioning (e. g., Cerella,

1990) . This theory has fallen out of favor because research shows that whether or not you observe slowing depends on what the task is. This is because all components of mental processing do not slow equivalently. Instead of cognitive decline being reduced to one basic change, slowing (Salthouse, Atkins, & Berish, 2003), an alternative perspec­tive suggests that age-related slowing is specific to particular levels of processing (e. g., response selec­tion) and that the level in which slowing affects processing may vary from one task to another (Allen, Madden, & Slane, 1995; Antsey, Hofer, & Luszez, 2003; MacDonald et al., 2003; Zimprich & Martin, 2002).