Key points are not available for this paper at this time.
It has recently been suggested that a large proportion of the age-related influences on many measures of cognitive functioning is mediated through a single common factor. This hypothesis has been supported by the discovery that much of the age-related variance in different cognitive measures is shared, and is not distinct or independent. These earlier results were replicated in this project, and it was also discovered that measures of corrected visual acuity and processing speed share a very large proportion of the age-related variance in measures of working memory, associative learning, and concept identification. The apparent implication is that the common factor that appears to contribute to age-related differences in many cognitive measures is quite broad and may reflect a relatively general reduction in central nervous system functioning.
Salthouse et al. (Fri,) studied this question.