Chapter 10 - Intelligence, Working Memory, and Learning Disabilities

Abstract

This chapter reviews some of our laboratory research on working memory (WM) in children with normal intelligence who have specific learning disabilities (LD) in reading and/or math. Two general conclusions emerge from this review. First, children with specific LD in reading and/or math are more likely to suffer general WM capacity constraints than average-achieving children, and these constraints are not entirely specific to their academic disability (i.e., reading or math) or intelligence. The reason is that constraints in WM capacity remain in individuals with LD when compared to their counterparts after the influence of achievement and psychometric IQ is partialed out in a statistical analysis. Second, constraints in WM capacity for children with LD are localized to isolated components of the phonological and executive systems. Difficulties related to the phonological system are related to the sequential recall of letters, numbers, real words, and pseudowords, whereas problems in executive processing are related to monitoring (decisions related to the allocation of attention) and interference (suppressing a competing memory trace that draws away from the targeted memory trace). It is further suggested that individuals with LD perform well on some measures of intelligence because (a) they compensate for WM limitations by increasing domain-specific knowledge and/or their reliance on environmental support; and/or (b) those domains or tasks do not place heavy demands on WM capacity.