Sentence comprehension in young children: Effects of phonological working memory, visual context and linguistic complexity

Previous research has documented a significant relationship between working memory capacity and language comprehension in adults and between working memory and aspects of language production in children. Surprisingly, a similar relationship between working memory capacity and language comprehension has not been found in typically developing children.; The influence of working memory capacity (WMC), variations in the length and complexity of the sentences to be processed, and the presence or absence of visual context an sentence was evaluated in 54 5- to 7-year-old children. Sentence comprehension was measured using an object manipulation participants enacted 32 active and passive simple and conjoined sentences using toy animals. The visual referents were presented simultaneously with the test sentences half of the time; for the rest of the time, the child was able to see the referents only after the presentation of test sentences.; While no effects of visual context or linguistic complexity on simple and conjoined sentence comprehension were found, a significant interaction between the effects of visual context and complexity on simple sentence comprehension was revealed while controlling for the effects of chronological age. Post-hoc hierarchical regression analyses revealed significant contributions of WMC (8% to 13%) to variability in sentence comprehension performance across several of the dependent measures.; The strength of two measures of WMC, the Competing Language Processing Task (CLPT) and the Nonword Repetition Task (NRT), as potential predictors of comprehension performance, was compared. Only the CLPT accounted for a significant amount (12%) of the variation in sentence comprehension after the effects of chronological age and lexical comprehension were partialled out. These results suggest that the CLPT may be a better measure of both the storage and computational aspects of WMC, while the NRT may measure, primarily, its storage component.; In this study, working memory capacity made significant contributions to sentence comprehension beyond those made by chronological age and lexical comprehension. Sentence comprehension in children was also influenced by tradeoff effects between intrinsic and extrinsic factors, such as visual context and linguistic complexity. The implications of these findings for clinical practice and further research are discussed.