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Dyscalculia
Developmental
dyscalculia
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. |
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While dyscalculia has been studied for many years in the
educational
field,
cognitive neuroscience research on dyscalculia is only just beginning.
However, judging by the progress with dyslexia research, we can hope
that in the next decade or two, we may have an idea of the brain areas
affected in dyscalculia, how to detect these abnormalities early in
life, and how to provide effective remediation.
Dyscalculia
research in our laboratory
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.
- Nicolas
Molko,
Arnaud Cachia, Denis Rivière, Jean-François
Mangin, Marie Bruandet, Denis LeBihan,
Laurent Cohen,
and
Stanislas Dehaene. Functional and structural
alterations of the intraparietal
sulcus in a developmental dyscalculia of genetic origin. Neuron,
40(4):847-858, 2003. [
PDF
]
- Marie
Bruandet, Nicolas Molko, Laurent
Cohen,
and
Stanislas Dehaene. A cognitive
characterization of
diyscalculia in Turner
syndrome. Neuropsychologia, 2003. [PDF
]
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.
- K. Kopera-Frye, Stanislas
Dehaene, and A. P. Streissguth.Impairments of number
processing induced
by prenatal alcohol exposure Neuropsychologia,
34:1187--1196, 1996.
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.
Further Information
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:
Back to the unicog
main page.
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