General Cognitive Changes with Aging
This chapter reviews the general cognitive changes that occur with normal aging and lead to the perceptions such as those described. It examines some general sensory changes related to aging. As with other physically related functions, cognitive efficiency unfortunately declines with normal aging, and may well account for more functional difficulties than the sensory changes. Although most cognitive abilities seem to decline with age, they do not all do so at the same rate, and decline as measured by cognitive tests may not reflect the real-world impact of abilities measured by those tests. The body of knowledge in cognition and aging is growing exponentially, and it appears that some general principles underlying the characteristics of cognitive change are emerging. There is both evidence for a generalized factor of cognitive aging, which affects multiple functions, and evidence of more specific decline in various functions themselves.