Introduction

Our goal is to investigate the role of the verbal working memory system in sentence comprehension, by presenting a model of working memory in sufficient detail to allow specific predictions to be made and tested. In testing this account, we draw on experimental methods that have recently been used in research on language development. These methods are designed to control the various sources of potential difficulty in the standard laboratory tasks used to assess children's grammatical knowledge and their use of this knowledge in sentence comprehension. We illustrate how our proposals about working memory, together with the recent innovations in method, allows us to infer that abnormal limitations in phonological processing, and not absence of grammatical knowledge, are at the root of the difficulties in spoken sentence understanding that are apparent in children with reading disability.

Since reading problems are most transparent at the beginning stages of learning to read, we focus our attention there, by investigating the linguistic abilities of poor readers in the early school years. By “poor readers” we mean children who show a marked disparity between their measured level of reading skill and the level of performance that might be expected in view of their intelligence and opportunity for instruction. Our research compares performance by these children with age-matched controls – children who are proceeding at the expected rate in the acquisition of reading skills (for discussion of the issues regarding subtypes of reading disability and choice of control groups, see Shankweiler, Crain, Brady & Macaruso, in press).