Perception and short-term memory for verbal information in children with specific language impairment: Further evidence for impaired short-term memory capacities

Abstract

Most children with specific language impairment (SLI) present impaired performance in verbal short-term memory (STM) tasks. Weismer et al. (2000), for example, showed that repetition of non-words of increasing length, a frequently used STM measure, was a very reliable marker for distinguishing children with and without SLI. This has led a number of authors to consider that a verbal STM impairment might represent one of the core deficits of SLI (e.g., Gathercole & Baddeley, 1990). However, there is still important controversy regarding this view as the verbal STM impairment could also be the consequence of underlying language impairments. For example, James, Van Steenbrugge, and Chiveralls (1994) observed deficits in speech perception that explained impaired performance observed in verbal STM tasks in their SLI group. Furthermore, another possibility which has not yet been extensively explored is that the poor development of SLI children's phonological and lexico-semantic representations stored in long-term memory (LTM) could also account for reduced performance in STM tasks. Indeed, a number of studies in normally developing children have recently shown that performance in STM tasks is very strongly influenced by the integrity of underlying LTM language representations, as evidenced by better recall for words compared to nonwords and better recall for non-words containing familiar versus less familiar phoneme associations (e.g., Gathercole, Frankish, Pickering, & Peaker, 1999). In this context, we re-examined the specificity of verbal STM deficits in SLI by exploring the influence of phonological and lexico-semantic LTM representations on STM performance as well as the integrity of speech perception abilities.