Perceptual-motor and attentional correlates of developmental dyscalculia.
From the patient population of a learning disorders clinic, a group of 72 "relative math underachievers" was selected for achievement test performance below grade level on mathematics but at or above grade level on reading, with a difference of at least 1.5 standard deviation between the two. A comparison group of 30 "relative reading underachievers" met the converse criteria. Neurological examination showed mixed laterality preference (right hand and foot but left eye) to be more prevalent among the math underachievers. The two groups were closely comparable on Wechsler intelligence quotient scores, although the "freedom from distractibility quotient" tended to be lower for the match group. The latter group also showed a lower mean achievement quotient on the Bender Visuomotor Gestalt Test. On a standard questionnaire derived from DSM-III criteria for attention deficit disorder, the math group showed higher scores for inattention, but not for hyperactivity, impulsivity, or poor peer relations. Both perceptual-motor and attentional deficits appear to characterize children who are specifically learning disabled for math.