Basic numerical skills in children with mathematics learning disabilities: A comparison of symbolic vs non-symbolic number magnitude processing

Defective number module or impaired access? Numerical magnitude processing in first graders with mathematical difficulties

“…Moreover, structural (Isaacs, Edmonds, Lucas, & Gadian, 2001;Rotzer et al, 2008) and functional (Mussolin et al, 2010;Price, Holloway, Rasanen, Vesterinen, & Ansari, 2007) There exists considerable evidence that representations of magnitude are impaired in children with mathematical difficulties (De Smedt, Reynvoet, et al, 2009;Geary et al, 2007Geary et al, , 2008Iuculano et al, 2008;Jordan, Kaplan, Olah, & Locuniak, 2006;Landerl et al, 2004Passolunghi & Siegel, 2004;Rousselle & Noël, 2007). However, the majority of these studies only relied on tasks with a symbolic processing requirement and do not allow us to clarify whether difficulties in mathematics result from difficulties in representing numerical magnitudes, as postulated in the defective number module hypothesis, or from difficulties in the ability to access numerical magnitudes from formal symbols, such as Arabic numerals, as assumed in the access deficit hypothesis.…”

“…Indeed, studies have demonstrated that children with mathematical difficulties have particular impairments in understanding and processing numerical magnitudes (De Smedt, Reynvoet, et al, 2009;Geary, Hoard, Byrd-Craven, Nugent, & Numtee, 2007;Geary, Hoard, Nugent, & Byrd-Craven, 2008;Landerl, Bevan, & Butterworth, 2004;Landerl, Fussenegger, Moll, & Willburger, 2009;Passolunghi & Siegel, 2004;Rousselle & Noël, 2007). Two accounts for these impairments have been put forward (Rousselle & Noël, 2007; see also Wilson & Dehaene, 2007).…”

“…Two accounts for these impairments have been put forward (Rousselle & Noël, 2007; see also Wilson & Dehaene, 2007). The defective number module hypothesis (Butterworth, 2005) proposes that a highly specific deficit of an innate capacity to understand and represent quantities leads to difficulties in learning number and arithmetic.…”

“…The defective number module hypothesis (Butterworth, 2005) proposes that a highly specific deficit of an innate capacity to understand and represent quantities leads to difficulties in learning number and arithmetic. The access deficit hypothesis (Rousselle & Noël, 2007) states that mathematical difficulties originate from impairments in accessing numerical meaning, i.e. their quantity, from symbols rather than from difficulties in processing numerosity per se.…”

“…To date, findings remain inconclusive and studies supporting both the defective number module hypothesis ) and the access deficit hypothesis (Iuculano, Tang, Hall, & Butterworth, 2008;Rousselle & Noël, 2007) have been reported. The present study aimed to contrast both hypotheses and to extend previous findings in two important ways.…”