Mathematical Difficulties in Nonverbal Learning Disability or Co-Morbid Dyscalculia and Dyslexia

a Department of Developmental and Social Psychology , University of Padova , Padova , Italy.
Developmental Neuropsychology (Impact Factor: 2.24). 08/2013; 38(6):418-32. DOI: 10.1080/87565641.2013.817583
Source: PubMed


The main goal of the present study was to shed further light on the weaknesses of children with different profiles of mathematical difficulties, testing children with nonverbal learning disability (NLD), co-morbid dyscalculia and dyslexia (D&D), or typical development (TD). Sixteen children with NLD, 15 with D&D, and 16 with TD completed tasks derived from Butterworth (2003 ) and divided into: a capacity subscale (i.e., a number-dots comparison task, a number comparison task, and a dots comparison task); and an achievement subscale (i.e., mental calculations and arithmetical fact retrieval). Children with NLD were impaired in the dots comparison task, children with D&D in the mental calculation and arithmetical facts.

Download full-text


Available from: Irene Cristina Mammarella,
  • Source
    • "Furthermore , individuals with reading disorder are impaired in verbal number tasks, such as counting, but seem to be unimpaired on nonverbal tasks tapping the ANS (e.g., G€ obel & Snowling, 2010; Moll, G€ obel, & Snowling, 2014). It has been argued, that problems in fact retrieval in children with dyslexia are mediated by their reading problems (Mammarella et al., 2013). Thus, poor arithmetic skills in children with reading disorder are associated with problems in language processing, rather than with problems in basic number processing. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Two important foundations for learning are language and executive skills. Data from a longitudinal study tracking the development of 93 children at family-risk of dyslexia and 76 controls was used to investigate the influence of these skills on the development of arithmetic. A two-group longitudinal path model assessed the relationships between language and executive skills at 3–4 years, verbal number skills (counting and number knowledge) and phonological processing skills at 4–5 years, and written arithmetic in primary school.
    Learning and Instruction 08/2015; 38. DOI:10.1016/j.learninstruc.2015.03.004 · 3.73 Impact Factor
  • Source
    • "Given Rourke et al.'s hypothesis (Rourke & Conway, 1997), which postulates that MD only and MD+RD difficulties are connected to different hemispheric dysfunctions, we would expect to find similar performances in the MD+RD and control groups and significant differences in the MD only group because of the specific deficit in numerical magnitude processing of this group. In fact, MD+RD difficulties would be related to phonological processing deficits, that could impair aspects of mathematics that rely on the manipulation of verbal codes, such as mental calculation and fact retrieval, but should not affect number comparison (Mammarella et al., 2013; Simmons & Singleton, 2008). In contrast, based on the studies that found similar results in basic numerical cognition in the two clinical groups (e.g., Cirino et al., 2013; Landerl et al., 2004; Landerl et al., 2009; Swanson et al., 2009), we would expect similar performances from the MD only and MD+RD children that should be significantly different from the performances of the control group because the impairment in basic numerical cognition is connected to MD (with or without RD). "
    [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to explore the spatial numerical association of response codes (SNARC), the flanker, and the numerical distance effects in children with mathematical difficulties. From a sample of 720 third, fourth, and fifth graders, 60 children were selected and divided into the following three groups: typically developing children (TD; n = 29), children with mathematical difficulties only (MD only; n = 21), and children with mathematical and reading difficulties (MD+RD; n = 10). Children were tested with a numerical Eriksen task that was built to assess SNARC, numerical distance, and flanker (first and second order congruency) effects. Children with MD only showed stronger SNARC and second order congruency effects than did TD children, whereas the numerical distance effects were similar across the three groups. Finally, the first order congruency effect was associated with reading difficulties. These results showed that children with mathematical difficulties with or without reading difficulties were globally more impaired when spatial incompatibilities were presented.
    Journal of Learning Disabilities 04/2014; DOI:10.1177/0022219414529335 · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the literature on numerical cognition, a strong association between numbers and space has been repeatedly demonstrated. However, only a few recent studies have been devoted to examine the consequences of low visuospatial abilities on calculation processing. In this study, we wanted to investigate whether visuospatial weakness may affect pure spatial processing as well as basic numerical reasoning. To do so, the performances of children with high and low visuospatial abilities were directly compared on different spatial tasks (the line bisection and Simon tasks) and numerical tasks (the number bisection, number-to-position, and numerical comparison tasks). Children from the low visuospatial group presented the classic Simon and SNARC (spatial numerical association of response codes) effects but showed larger deviation errors as compared with the high visuospatial group. Our results, therefore, demonstrated that low visuospatial abilities did not change the nature of the mental number line but rather led to a decrease in its accuracy. Copyright © 2014 Elsevier Inc. All rights reserved.
    Journal of Experimental Child Psychology 01/2015; 132C:84-98. DOI:10.1016/j.jecp.2014.12.006 · 3.12 Impact Factor
Show more