What is Normal Cognitive Aging? Evidence from Task-Based Functional Neuroimaging.

The idea that our cognitive abilities change with age has support from empirical research as well as from anecdotal reports. Cognition has many component processes, some of which are impaired by normal aging like attention and memory as a result of changes in perceptual systems or speed of processing. Other cognitive domains improve in functioning as aging continues such as wisdom and some kinds of decision making. Many years of research in the psychology of cognitive aging has described patterns of age-related changes in cognitive processes with older adults performing worse than younger adults on tests of attention, working memory and episodic memory and better on tests of general knowledge. More recent work in task-related functional neuroimaging has further elucidated the effects of aging on brain circuitry related to these cognitive processes. Generally, studies show that older adults activate regions of the frontal cortex more than younger adults while younger adults activate more posterior cortical areas. This paper describes normal patterns of cognitive change in healthy aging, describes how some of these processes can be explored with functional neuroimaging, and briefly describes the work attempting to describe differences between normal and pathological cognitive aging.