title: Developmental dyscalculia and brain laterality.
abstract: The correlation between arithmetic dysfunction and brain laterality was studied in 25 children with developmental dyscalculia (DD). The children were tested on a standardized arithmetic battery and underwent a neurological and neuro-psychological evaluation. A diagnosis of left hemisphere dysfunction (n = 13) was based on right side soft neurological signs, performance IQ (PIQ) > verbal IQ (VIQ), dyslexia and intact visuo-spatial functions. The criteria for right hemisphere dysfunction (n = 12) were left body signs, VIQ > PIQ, impaired visuo-spatial functions and normal language skills. The groups were similar for age, gender, and socio-economic status. Our results showed that both groups scored more than 2 SD below the mean adjusted score on the arithmetic battery, but the left group was significantly worse in 3 areas: mastery of addition/subtraction, complex multiplication and division and visuo-spatial errors (p < 0.05). The data indicate that dysfunction of either hemisphere hampers arithmetic acquisition, but arithmetic impairment is more profound with left hemisphere dysfunction.
authors.affiliation: Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem, Israel.
authors.forename: R S
authors.initials: RS
authors.lastname: Shalev
authors.forename: O
authors.initials: O
authors.lastname: Manor
authors.forename: N
authors.initials: N
authors.lastname: Amir
authors.forename: R
authors.initials: R
authors.lastname: Wertman-Elad
authors.forename: V
authors.initials: V
authors.lastname: Gross-Tsur
mesh_terms: D000293:Adolescent; D001921:Brain / Q000254:growth & development / Q000503:physiopathology*; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D002658:Developmental Disabilities / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008433:Mathematics; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D013647:Task Performance and Analysis