title: Stable measures of number sense accuracy in math learning disability: Is it time to proceed from basic science to clinical application?
abstract: Math learning disability (MLD) or developmental dyscalculia is a highly prevalent and persistent difficulty in learning arithmetic that may be explained by different cognitive mechanisms. The accuracy of the number sense has been implicated by some evidence as a core deficit in MLD. However, research on this topic has been mainly conducted in demographically selected samples, using arbitrary cut-off scores to characterize MLD. The clinical relevance of the association between number sense and MLD remains to be investigated. In this study, we aimed at assessing the stability of a number sense accuracy measure (w) across five experimental sessions, in two clinically defined cases of MLD. Stable measures of number sense accuracy estimate are required to clinically characterize subtypes of MLD and to make theoretical inferences regarding the underlying cognitive mechanisms. G. A. was a 10-year-old boy with MLD in the context of dyslexia and phonological processing impairment and his performance remained steadily in the typical scores range. The performance of H. V., a 9-year-old girl with MLD associated with number sense inaccuracy, remained consistently impaired across measurements, with a nonsignificant tendency to worsen. Qualitatively, H. V.'s performance was also characterized by greater variability across sessions. Concomitant clinical observations suggested that H. V.'s difficulties could be aggravated by developing symptoms of mathematics anxiety. Results in these two cases are in line with the hypotheses that at least two reliable patterns of cognitive impairment may underlie math learning difficulties in MLD, one related to number sense inaccuracy and the other to phonological processing impairment. Additionally, it indicates the need for more translational research in order to examine the usefulness and validity of theoretical advances in numerical cognition to the clinical neuropsychological practice with MLD.
authors.affiliation: Programa de Pós-graduação em Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.|Developmental Neuropsychology Laboratory, Department of Psychology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Annelise
authors.initials: A
authors.lastname: Júlio-Costa
authors.affiliation: Programa de Pós-graduação em Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.|Developmental Neuropsychology Laboratory, Department of Psychology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Isabella
authors.initials: I
authors.lastname: Starling-Alves
authors.affiliation: Programa de Pós-graduação em Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.|Programa de Pós-graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Júlia Beatriz
authors.initials: JB
authors.lastname: Lopes-Silva
authors.affiliation: Department of Neuropsychology, Institute of Psychology, Karl-Franzens-University of Graz, Graz, Austria.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Wood
authors.affiliation: Programa de Pós-graduação em Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.|Developmental Neuropsychology Laboratory, Department of Psychology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.|Programa de Pós-graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Vitor Geraldi
authors.initials: VG
authors.lastname: Haase
mesh_terms: D000124:Achievement; D001007:Anxiety; D002648:Child; D003072:Cognition Disorders; D060705:Dyscalculia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007859:Learning Disabilities / Q000523:psychology; D008297:Male; D008433:Mathematics / Q000193:education*; D008570:Memory, Short-Term; D009483:Neuropsychological Tests
keywords: Weber fraction; developmental dyscalculia; mathematical learning disabilities; number sense; single-case study