|
 What is dyscalculia? As defined by researcher L. Kosc [1] dyscalculia is a difficulty in mathematics as a as a result of impairment to particular parts of the brain involved in mathematical cognition, but without a general difficulty in cognitive function. The DSM-IV, a manual used by the medical and mental health community, also uses the terms "Mathematics Disorder" and "Mathematical Disabilities".
Will my school diagnose dyscalculia in my child? Although cognitive neurologists use this definition today, schools rarely diagnose their students with dyscalculia. Instead of determining dyscalculia, many schools will state students have a "specific learning disability" in the Individual Education Plan [IEP]. Unfortunately, this broad term may delay appropriate remediation and treatment. By law, if a school diagnoses dyscalculia and states it in a student's IEP, then the school must treat the cognitive disorder with science-proven methods and show progress.
What percentage of the population has dyscalculia? The percentage of the population with developmental dyscalculia is estimated to be between 3-6 percent, or one in twenty individuals [2-4]. This is a lower percentage than the 20 percent of the population with dyslexia. Hence, in comparison dyscalculia is very understudied and under-resourced. Like dyslexia, dyscalculia is as likely to affect girls as boys.
How is dyscalculia diagnosed? Because there is no gene or brain function yet directly identified with dyscalculia, we must diagnose based on a student's difficulty with mathematics. Many variables may contribute to being bad at "math." These include inadequate instruction, attention deficits, anxiety disorders, and lack of motivation. Therefore, it is important that the evaluation include a variety of tests, including math operations, overall IQ, tests for reading disorders and attention deficits. Due to liability concerns and expense, schools will rarely screen students for ADD/ADHD, dyslexia or dyscalculia. Independent psychologists may perform all of the tests required to determine these diagnoses, but parents should ask if they specifically test and diagnose for these disabilities before you employ them.
What causes dyscalculia? Research with infants suggests that numerosity is innate. As there are humans with genomic tendencies to genius in mathematics, there are also those with the tendency to fail to develop specialized brain pathways for mathematics. Although researchers have not yet identified the exact brain dysfunction causing math difficulties, they should be able to isolate the neurology responsible in the next few years. After educators know more about the symptoms of dyscalculia, how it develops over childhood, and its brain bases, better tests will be created to use earlier for detecting and treating dyscalculia. One test designed specifically to detect dyscalculia, is Brian Butterworth's Dyscalculia Screener.
What is the root cause of dyscalculia? Dyscalculia frequently co-occurs with other learning deficits such as attention deficit and hyperactivity disorder (ADHD), dyspraxia, dyslexia, and specific language impairment (SLI). Researchers surmise that this is due to environmental and genetic factors acting on several areas of the brain at once affecting brain development. Known genetic disorders such as Turner's syndrome, Fragile X syndrome, Velocardiofacial syndrome, Williams syndrome impact learning. In addition studies suggest that there are genes present in the general population that increase the risk of dyscalculia [6,7]. Recognized environmental sources include alcohol consumption during pregnancy, and pre-term birth as these can result in brain underdevelopment.
Is there a kindergarten or early grade school screening for dyscalculia? Presently there is no early detection assessment for dyscalculia. Usually what happens is that by the time parents and teachers realize a child has a severe problems with mathematics, the child is in third or fourth grade and 3 years behind in school. Ideally, all children would be tested in kindergarten, and selected out as at risk for dyscalculia so that they receive monitoring and remediation. In this way dyscalculia could be "prevented".
What methods can help a child or adult with dyscalculia? We know that the human brain is plastic and able to be changed, especially in childhood. Even the adult brain remains plastic and is able to change with intensive remediation and therapy. Science-based intervention programs show impressive results for subjects with severe learning disabilities. We know from research on dyslexia that multi-sensory interventions result in significant reading improvement associated with brain function changes [8,9]. In our twelve-year practice with dyslexic clients, we know that consistently applied multisensory-guided practice sustains new learning behaviors that lead to mastery. Similar results are occurring with our math clients.
References
- [1] L. Kosc, "Developmental Dyscalculia," Journal of Learning Disabilities, vol. 7, pp. 164-77, 1974.
- [2] V. Gross-Tsur, O. Manor, and R. S. Shalev, "Developmental dyscalculia: prevalence and demographic features.," Dev Med Child Neurol, vol. 38, pp. 25-33, 1996.
- [3] N. A. Badian, "Persistent Arithmetic, Reading, or Arithmetic and Reading Disability," Annals of Dyslexia, vol. 49, pp. 45-70, 1999.
- [4] C. Lewis, G. J. Hitch, and P. Walker, "The prevalence of specific arithmetic difficulties and specific reading difficulties in 9- to 10-year old boys and girls," Journal of Child Psychology and Psychiatry, vol. 35, pp. 283-292, 1994.
- [5] Fuson, K. C. (1992). 'Relationships between counting and cardinality from age 2 to 8.' In: Bideaud, J., Meljac, C. and Fisher, J. P. (Eds.) Pathways to Number, Pupils' Developing Numerical Abilities. Hillsdale, NJ: LEA.
- [6] M. Alarcon, J. C. DeFries, J. G. Light, and B. F. Pennington, "A Twin Study of Mathematics Disability," Journal of learning disabilities, vol. 30, pp. 617-623, 1997.
- [7] R. S. Shalev, O. Manor, B. Kerem, M. Ayali, N. Badichi, Y. Friedlander, and V. Gross-Tsur, "Developmental Dyscalculia Is a Familial Learning Disability," Journal of Learning Disabilities, vol. 34, pp. 59-65, 2001.
- [8] M. M. Merzenich, W. M. Jenkins, P. Johnston, C. Schreiner, S. L. Miller, and P. Tallal, "Temporal Processing Deficits of Language-Learning Impaired Children Ameliorated by Training," Science, vol. 271, pp. 77-81, 1996.
- [9] E. Temple, G. K. Deutsch, R. A. Poldrack, S. L. Miller, P. Tallal, M. M. Merzenich, and J. D. Gabrieli, "Neural deficits in children with dyslexia ameliorated by behavioral remediation: evidence from functional MRI," Proc Natl Acad Sci U S A, vol. 100, pp. 2860-5., 2003.
|
