Processing speed, attentional capacity, and age-related memory change.

This study compared the relative importance (i.e., proportion of shared variance) of attentional capacity and processing speed accounts of cognitive aging to predict age differences in episodic and working memory performance. Right-handed adults (n = 100), 18 to 88 years of age, completed measures of attentional capacity (divided attention), processing speed, and episodic and working memory. The results provide little support for the predictive utility of the attentional capacity construct, independent of processing speed ability in accounting for age-specific episodic memory relations. The results are, however, consistent with the notion that attentional capacity mediates aspects of age-related working memory change.