"Brain furrow may cause maths problem," by Helen Pearson. Nature Science Update, 13 November 2003.
Nicolas Molko and his colleagues at INSERM (the French Institute of Health and Medical Research in Paris) have studied people with dyscalculia (difficulty conceiving arrangements of numbers, similar to "dyslexia" in which individuals have difficulty with letters). The researchers have found that "dyscalculics have abnormal pulses of activity in a brain furrow called the right intraparietal sulcus, the fissure that helps the mind to conjure spatial images." The conclusion of the researchers and others is that dyscalculia is but one kind of learning difficulty and that other disorders---as well as medicocre teaching, poor motivation, fear, and dislike of the subject---play a role in learning (or not learning) mathematics.
--- Annette Emerson