Symbolic and nonsymbolic number comparison in childrenwith and without dyscalculia

摘要

Developmental dyscalculia (DD) is a pervasive difficulty affecting number processing andarithmetic. It is encountered in around 6% of school-aged children. While previous studieshave mainly focused on general cognitive functions, the present paper aims to furtherinvestigate the hypothesis of a specific numerical deficit in dyscalculia. The performanceof 10- and 11-year-old children with DD characterised by a weakness in arithmetic factsretrieval and age-matched control children was compared on various number comparisontasks. Participants were asked to compare a quantity presented in either a symbolic (Arabicnumerals, number words, canonical dots patterns) or a nonsymbolic format (noncanonicaldots patterns, and random sticks patterns) to the reference quantity 5. DD children showeda greater numerical distance effect than control children, irrespective of the number for-mat. This favours a deficit in the specialised cognitive system underlying the processingof number magnitude in children with DD. Results are discussed in terms of access and rep-resentation deficit hypotheses.