Developmental dyscalculia is a difficulty in learning mathematics which is thought to affect 3-6% of the population and may be due, at least in part, to a dysfunction of areas of the brain that represent numerical information.
Our laboratory has been investigating the organization of the number sense, and the role of the intraparietal sulcus in calculation in normal subjects. For a more complete description of all of our numerical cognition research, see the numbers page.We postulate that the circuits that are seen as active during arithmetic in normal subjects, particularly the intraparietal sulcus, may be partially deficient or disconnected in patients with dyscalculia. We have documented this hypothesis in several cases of adult acalculia (acquired deficits of calculation in adult patients following a brain insult). We are now beginning to see evidence that a similar explanation may hold, in a developmental context, for children with developmental dyscalculia.
Two recent reviews of our approach are available, one in English, the other in French:
Nicolas Molko conducted work in our laboratory with Turner's syndrome (45X), a genetic syndrome associated with dyscalculia, finding that adult Turner's syndrome women showed both anatomical and functional abnormalities in the parietal sulcus.
In collaboration with Ann Streissguth’s team in Seattle, we have also shown that foetal alcohol syndrome (exposure of the foetus to alcohol during pregnancy) is often accompanied by striking deficits of number processing.
Can dyscalculia be remediated ?
In our laboratory, Anna Wilson and Stanislas Dehaene have developed and are now testing a new tool for the remediation of dyscalculia,an adaptive computer game ("The Number Race") designed especially to help children practice their quantity manipulation skills and the links from quantity to Arabic numerals and number words. The software includes a multidimensional adaptive computer algorithm that can detect in which domain a child experiences difficulty, and present problems at the relevant level, difficult enough to be challenging, but easy enough to avoid discouragement.This software is free and can be downloaded here.
Parents of dyscalculic children often ask us what they can do to help their children. Unfortunately, much less is known about dyscalculia than dyslexia. Notwithstanding, research is increasing our knowledge, and awareness of dyscalculia is growing. Anna Wilson has created a website which aims to bring research-based information about dyscalculia to parents, teachers and policy makers: www.aboutdyscalculia.org. This site includes links to other websites, other resources for parents and teachers.
In addition, we have written a short guide which outlines what is known thus far, and gives links to further resources: