Working memory, short-term memory, speech rate, word recognition and reading comprehension in learning disabled readers: does the executive system have a role?

Abstract

This study explored the contribution of two working memory systems (the articulatory loop and the central executive) and short-term memory to the word recognition and comprehension deficits of children with learning disabilities (LD). In Experiment 1, performance of LD, chronological age (CA)-matched, and reading level (RL)-matched children was compared on measures of articulation rate, short-term memory (STM), and working memory (WM). Experiment 2 included the same procedures as Experiment 1, except that WM tasks were administered under cued-recall conditions. The results indicated that (a) LD readers' STM and WM performance was inferior to CA-matched and RL matched readers when articulation speed (the articulatory system) was partialed from the analysis and (b) WM predicted word recognition and comprehension performance independent of the contribution of STM and articulatory rate. The results were interpreted as support for the notion that LD readers' poor word recognition and comprehension performance reflected deficits in a central executive system independent of their deficits in the articulatory loop.