An international team of scientists have discovered that the brain’s right parietal lobe is responsible for the disorder, dyscalculia, a kind of numerical dyslexia. The discovery made by researchers at University College London, University of the Negev, Israel, Birkbeck Centre for Brain and Cognitive Development, London, Maastricht University, Netherlands, and the Max Planck Institute for Brain Research, Germany, could ultimately lead to new methods of diagnosis and management of the disorder through remedial teaching.
Dyscalculia is as common as dyslexia and attention deficit hyperactivity disorder (ADHD) with about one in twenty people affected. However, dyscalculia has been given little regard in the mainstream despite its potentially debilitating impact on quality of life. Roi Cohen Kadosh, of UCL’s Institute of Cognitive Neuroscience explains the implications of his study, which involved inducing dyscalculia: “This is the first causal demonstration that the parietal lobe is the key to understanding developmental dyscalculia,” he explains, “Most people process numbers very easily — almost automatically — but people with dyscalculia do not.” The team stimulated for a few milliseconds the right parietal lobes of volunteers carrying out an arithmetic test, using neuronavigated transcranial magnetic stimulation (TMS) . The stimulation essentially knocked out activity in that part of the brain and left the volunteers unable to react as quickly to the test.
“This provides strong evidence that dyscalculia is caused by malformations in the right parietal lobe and provides sold grounds for further study on the physical abnormalities present in dyscalculics’ brains,” adds Cohen Kadosh, “It’s an important step to the ultimate goal of early diagnosis through analysis of neural tissue, which in turn will lead to earlier treatments and more effective remedial teaching.”
The researchers will publish details of their findings in the April 17 issue of the journal Current Biology