Reading comprehension and working memory in learning-disabled readers: Is the phonological loop more important than the executive system?

This investigation explores the contribution of two working memory systems (the articulatory loop and the central executive) to the performance differ ences between learning-disabled (LD) and skilled readers. Performances of L D, chronological age (CA) matched, and reading level-matched children were compared on measures of phonological processing accuracy and speed (articul atory system), long-term memory (LTM) accuracy and speed, and executive pro cessing. The results indicated that (a) LD readers were inferior on measure s of articulatory, LTM, and executive processing; (b) LD readers were super ior to RL readers on measures of executive processing, but were comparable to RL readers on measures of the articulatory and LTM system; (c) executive processing differences remained significant between LD and CA-matched chil dren when measures of reading comprehension, articulatory processes, and LT M processes were partialed from the analysis; and (d) executive processing contributed significant variance to reading comprehension when measures of the articulatory and LTM systems were entered into a hierarchical regressio n model. In summary, LD readers experience constraints in the articulatory and LTM system, but constraints mediate only some of the influence of execu tive processing on reading comprehension. Further, LD readers suffer execut ive processing problems nonspecific to their reading comprehension problems . (C) 1999 Academic Press.