REDUCED RESOURCES AND SPECIFIC IMPAIRMENTS IN NORMAL AND APHASIC SENTENCE COMPREHENSION

Our recent article (Miyake, Carpenter, & Just, 1994) posits that compr ehension breakdown in aphasic patients arises, in part, from reduced w orking memory resources for language. One issue that we consider in th is article concerns the nature of the deficits postulated in the theor y, in contrast to two alternative views of the deficit: (1) a proposal cast in terms of a partial loss of knowledge rather than reduced reso urces, and (2) a proposal that there is a separate resource pool for s yntactic processing, rather than a more general pool for language comp rehension. A second issue that we address here concerns patterns of se lective sparing and impairment among some patients that have often bee n interpreted as indicating specific impairments in sentence processin g operations. We argue that such micro-level dissociations at a fine-g rain level of analysis can arise for many reasons other than selective impairments and, more specifically, that the occurrence of analogous patterns in normal adults challenges the common interpretations of dou ble dissociations regarding sentence comprehension deficits.