Abstracts - Earli

The development of strategy use in elementary-school children: working memory and individualdifferencesIneke Imbo, Ghent University, BelgiumAndre Vandierendonck, Ghent University, BelgiumThe present study tested the development of working-memory involvement in children’sarithmetic strategy selection and strategy efficiency. To this end, an experiment – in which thedual-task method and the choice/no-choice method were combined – was administered to 10-, 11-,and 12-year-old children. The dual-task method enabled us to obtain arithmetic performance dataunder two conditions: one without an additional working-memory load and one in which theexecutive component of working memory was loaded. The choice/no-choice method enabled us toobtain unbiased data on both strategy selection and strategy efficiency. We also obtained severalindividual-difference variables from each child, such as short-term memory span, processingspeed, arithmetic skill, gender, and math anxiety. The results showed that working memory wasneeded in order to execute all strategies (retrieval, transformation, and counting) efficiently.Working memory was not needed in strategy selection though. Importantly, the ratio betweenavailable working-memory resources, on the one hand, and arithmetic task demands, on the otherhand, changed across age. More frequent retrieval use, more efficient memory retrieval, and moreefficient counting processes reduced the working-memory requirements. However, the decrease inworking-memory involvement was not related to age-related increases in the efficiency oftransformation processes or to age-related increases in the efficiency of general processes (e.g.,encoding stimuli and pronouncing answers). Strategy efficiency and strategy selection were alsomodified by individual differences such as processing speed, arithmetic skill, gender, and mathanxiety. Short-term memory capacity, on the other hand, was not related to children’s strategyselection or strategy efficiency. It is concluded that working memory plays a significant role inchildren’s arithmetic performance. However, as children grow older, fewer working-memoryresources are needed. Finally, the importance of individual differences in arithmetic problemsolving provides interesting ideas for future research.Working memory and mathematical disabilities: evidence from Velo-Cardio-Facial syndrome?Bert De Smedt, K.U.Leuven, BelgiumAnn Swillen, K.U.Leuven, BelgiumLieven Verschaffel, K.U.Leuven, BelgiumPol Ghesquiere, K.U.Leuven, BelgiumIt has been hypothesized that mathematical disabilities (MD) are due to impairments in workingmemory. In the present study, we examined this association between working memory and mathimpairment in children with a genetic disorder known to be at risk for the development of MD,namely children with Velo-Cardio-Facial Syndrome (VCFS). More specifically, we investigatedwhether the MD of these children are due to deficits in working memory. Performance of twentyfivechildren with VCFS (age range: 6 – 12 years) was compared with a carefully selectedindividually matched control group. All children completed assessments of various mathematicalabilities (single-digit arithmetic, multidigit arithmetic and word problem solving) as well asmeasures of working memory. Children with VCFS performed significantly slower on single-digitaddition and subtraction and were significantly less accurately in solving multidigit calculationsand word problems. They did not differ from controls on the highly retrieval based multiplicationtask, which suggests that fact retrieval is preserved in children with VCFS. Thus, the difficulties ofchildren with VCFS in mathematics appear to be mainly of a procedural nature. Turning toworking memory, children with VCFS performed significantly higher on the phonological loop– 38 –