Longitudinal mediators of achievement in mathematics and reading in typical and atypical development.

Barnes MA, Raghubar KP, English L, Williams JM, Taylor H, Landry S. (2013) Longitudinal mediators of achievement in mathematics and reading in typical and atypical development. Journal of Expimental Child Psychology. 2014 Mar;119:1-16. 

Longitudinal studies of neurodevelopmental disorders that are diagnosed at or before birth and are associated with specific learning difficulties at school-age provide one method for investigating developmental precursors of later-emerging academic disabilities. Spina bifida myelomeningocele (SBM) is a neurodevelopmental disorder associated with particular problems in mathematics, in contrast to well-developed word reading. Children with SBM (n=30) and typically developing children (n=35) were used to determine whether cognitive abilities measured at 36 and 60months of age mediated the effect of group on mathematical and reading achievement outcomes at 8.5 and 9.5years of age. A series of multiple mediator models showed that: visual-spatial working memory at 36months and phonological awareness at 60months partially mediated the effect of group on math calculations, phonological awareness partially mediated the effect of group on small addition and subtraction problems on a test of math fluency, and visual-spatial working memory mediated the effect of group on a test of math problem solving. Groups did not differ on word reading, and phonological awareness was the only mediator for reading fluency and reading comprehension. The findings are discussed with reference to theories of mathematical development and disability and with respect to both common and differing cognitive correlates of math and reading.

doi: 10.1016/j.jecp.2013.09.006.

Do children with myelomeningocele and hydrocephalus display nonverbal learning disabilities?

Yeates KO, Loss N, Colvin AN, Enrile BG. Do children with myelomeningocele and hydrocephalus display nonverbal learning disabilities? An empirical approach to classification. Journal of the International Neuropsychological Society. 2003 May;9(4):653-62.

As a group, children with myelomeningocele (MM) and early-onset hydrocephalus demonstrate many of the features of the syndrome of nonverbal learning disabilities (NLD). However, the frequency with which individual children display a pattern of neuropsychological functioning consistent with the NLD syndrome is unknown. We addressed this question by comparing the prevalence of NLD in 32 children with MM and shunted hydrocephalus to that in a group of 27 healthy siblings. Participants, who were between 8 and 15 years of age, completed a neuropsychological test battery that included 11 measures of possible assets and 17 measures of possible deficits that define the NLD syndrome. As a group, children with MM and shunted hydrocephalus displayed many of the specific assets and deficits. However, they also displayed significantly more variability in their patterns of assets and deficits than siblings, reflecting the substantial individual differences that characterize children with MM. About 50% of the children with myelomeningocele displayed a pattern of assets and deficits consistent with the NLD syndrome. Classification as NLD was weakly related to cumulative medical risk, as well as to left-handedness. The findings suggest a need for caution in making generalizations regarding the applicability of the NLD model to children with MM and early-onset hydrocephalus.

PMID: 12755177