It is not clear why verbal working memory is impaired, even when language deficits are controlled for, while visual working memory remains normal. One possibility is that poor visuo-spatial memory skills are found only in a subgroup of children with SLI (Archibald and Gathercole, 2006a). Another possibility is that working memory itself is actually Ku-0059436 concentration largely normal in SLI, and that problems in verbal working memory are due to the language deficits in the disorder (Alloway et al., 2009). In the current study, verbal working memory deficits remained, though with reduced effect sizes, once the language composite was covaried
out. However, it is possible that controlling for other language measures (e.g., of phonology) might further reduce or eliminate the observed verbal working memory deficit. Further studies seem warranted to elucidate the apparent dichotomy between impaired verbal but normal visual working memory in SLI. The PDH expects declarative memory to remain largely normal in the disorder. The finding that children with SLI were spared not only at visual declarative memory, but also at verbal declarative memory once working memory and language deficits were accounted for, supports this prediction. The sparing of visual aspects of declarative memory is consistent
with previous studies (see, Introduction). Together, this and other studies http://www.selleckchem.com/products/SB-203580.html suggest that visual declarative memory remains largely intact in SLI. As we have seen, previous studies of verbal declarative memory have reported a mixed pattern of results in SLI. In particular, immediate recall in list or story learning paradigms has
generally been found to be impaired, while performance after a delay is inconsistent across studies. Based on the results of the current study, we hypothesise that previous inconsistent findings in SLI research with respect to delayed memory measures, and indeed declarative memory in general, might reflect at least in part individual or task differences in demands placed on working memory and language. Miconazole Indeed, in this study, after holding these two variables constant, no SLI impairments in verbal declarative memory were observed. This pattern of results is consistent with a profile of some working memory impairments, but with spared declarative memory, even in the verbal domain (Ullman and Pierpont, 2005). The correlations between declarative memory and lexical abilities in both the TD and SLI children support the predictions of the PDH, and of the declarative/procedural (DP) theory more generally, that lexical memory depends on declarative memory, and that simple (underived) words must always be learned in this system (Ullman, 2001, Ullman, 2004, Ullman, 2007 and Ullman and Pierpont, 2005).