This research received partial support from Grant RO1 HD34061-01-09 from the National Institute of Child Health and Human Development.
Impaired Acuity of the Approximate Number System Underlies Mathematical Learning Disability (Dyscalculia)
Article first published online: 16 JUN 2011
© 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.
Volume 82, Issue 4, pages 1224–1237, July/August 2011
How to Cite
Mazzocco, M. M. M., Feigenson, L. and Halberda, J. (2011), Impaired Acuity of the Approximate Number System Underlies Mathematical Learning Disability (Dyscalculia). Child Development, 82: 1224–1237. doi: 10.1111/j.1467-8624.2011.01608.x
- Issue published online: 11 JUL 2011
- Article first published online: 16 JUN 2011
Many children have significant mathematical learning disabilities (MLD, or dyscalculia) despite adequate schooling. The current study hypothesizes that MLD partly results from a deficiency in the Approximate Number System (ANS) that supports nonverbal numerical representations across species and throughout development. In this study of 71 ninth graders, it is shown that students with MLD have significantly poorer ANS precision than students in all other mathematics achievement groups (low, typically, and high achieving), as measured by psychophysical assessments of ANS acuity (w) and of the mappings between ANS representations and number words (cv). This relation persists even when controlling for domain-general abilities. Furthermore, this ANS precision does not differentiate low-achieving from typically achieving students, suggesting an ANS deficit that is specific to MLD.