Brain Matters

No Data; Doesn't Compute

Tuesday, April 3, 2007

The Problem Lots of us think we stink at math. Now some of us can claim we're not to blame: Our anatomy is. Researchers at the University College London recently pinpointed an area of the brain that, in some people, appears to be the source of a profound inability to process numbers, known as dyscalculia -- the math equivalent of dyslexia. That would be your right intraparietal sulcus, according to the small study, which appears in the April 17 issue of the journal Current Biology.

The Study Roi Cohen Kadosh of the college's Institute of Cognitive Neuroscience and colleagues had five people with normal math ability and five diagnosed with dyscalculia compare the relative magnitude of pairs of numbers, a math task so basic that most people perform it automatically. Participants were asked to determine which was numerically larger, 2 or 4 -- when the 2 appeared in a larger typeface than the 4.

The normal participants received a harmless magnetic stimulus to the right intraparietal sulcus, which is sandwiched between the frontal and anterior lobes, at the instant that they compared the two digits. When thus impaired, they had more difficulty identifying the "bigger" number than when there was no such stimulus. Their performance mirrored that of the dyscalculic participants.

Researchers hope the findings will one day permit the use of brain imaging to determine those at risk as early as possible and a "remediation program that will take part at both the behavioral and the neuronal level," Cohen Kadosh wrote in an e-mail.

The Caveat Do your math homework just the same; it's not a good bet the teacher will buy your excuse. Dyscalculia is thought to affect only 5 percent of the population.

-- Jennifer Huget

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