Numerous authors have examined the relationship between speed of processing, working memory and age, and debated the role of these concepts in understanding individual differences in cognitive ability. There are arguments as to the relative contributions of both concepts, and most theorists tend to agree that slowing is the explanation for cognitive decline.
Using tasks that draw on working memory (holding placekeepers in mind) and fluid intelligence (task complexity incrementally increasing), it has been found that both speed and working memory are important for our understanding of individual differences. It is unlikely that speed of processing can completely explain the decline in fluid intelligence with age.
» Read more