Working memory and processing speed mediate the effect of age on a general ability construct: evidence from the Italian WAIS-IV standardization sample
We used structural equation modeling to study individual age-related differences in working memory, processing speed, and the general ability of intelligence. The study took advantage of the Italian Wechsler Adult Intelligence Scale 4th edition (WAIS-IV) standardization sample (N=2174) to obtain separate measures of working memory, processing speed, and general ability. Core and supplemental subtests were administered to 16–90 years old participants to ensure breadth of cognitive assessment and broad age coverage.