Memory, Language Comprehension, and Mental Retardation

There is a long history of research conducted on memory systems and processes of persons with mental retardation. In fact, the relation between memory ability and general intellectual ability was part of many of the earliest intelligence tests (see Estes, 1982). In terms of basic memory systems, researchers have evaluated the performance of persons with mental retardation relative to persons without mental retardation in short-term, immediate, or working memory (e.g., Cohen & Sandberg, 1980; Ellis, 1970), long-term memory (e.g., Prehm & Mayfield, 1970; Sperber, Greenfield, & House, 1973), semantic memory (e.g., Glidden, 1986; Sperber & McCauley, 1984), episodic memory (Stan & Mosley, 1988), tacit memory (Atwell, Conners, & Merrill, 2003), and the possible interactions of some of the various memory systems (e.g., Cody & Borkowski, 1977; Winters, 1986). In terms of memory processes, considerable research attention has been devoted to the study of meta-memory and the use of task-specific memory strategies by persons with and without mental retardation (e.g., Borkowski & Cavanaugh, 1979; Brown&Campione, 1977; Justice, 1986), automatic versus effortful memory retrieval processes (e.g., Ellis, Palmer, &Reeves, 1988; Ellis, Woodley-Zanthow, & Dulaney, 1989), memory scanning (e.g., Merrill, 1990; Phillips &Nettelbeck, 1986), semantic priming (e.g., Sperber, Davies,Merrill, & McCauley, 1982; Sperber, Ragain, & McCauley, 1976), and semantic inhibition (e.g., Cha & Merrill, 1994; Merrill & Taube, 1996). Memory has always played an important role in the study of language comprehension in cognitive psychology (see Lorch & van den Brock, 1997). In fact, discourse comprehension is often viewed as the cognitive equivalent of constructing a coherent memory representation of the text or discourse during its processing and early models of discourse comprehension relied