title: Development of brain systems for nonsymbolic numerosity and the relationship to formal math academic achievement.
abstract: A central question in cognitive and educational neuroscience is whether brain operations supporting nonlinguistic intuitive number sense (numerosity) predict individual acquisition and academic achievement for symbolic or "formal" math knowledge. Here, we conducted a developmental functional magnetic resonance imaging (MRI) study of nonsymbolic numerosity task performance in 44 participants including 14 school age children (6-12 years old), 14 adolescents (13-17 years old), and 16 adults and compared a brain activity measure of numerosity precision to scores from the Woodcock-Johnson III Broad Math index of math academic achievement. Accuracy and reaction time from the numerosity task did not reliably predict formal math achievement. We found a significant positive developmental trend for improved numerosity precision in the parietal cortex and intraparietal sulcus specifically. Controlling for age and overall cognitive ability, we found a reliable positive relationship between individual math achievement scores and parietal lobe activity only in children. In addition, children showed robust positive relationships between math achievement and numerosity precision within ventral stream processing areas bilaterally. The pattern of results suggests a dynamic developmental trajectory for visual discrimination strategies that predict the acquisition of formal math knowledge. In adults, the efficiency of visual discrimination marked by numerosity acuity in ventral occipital-temporal cortex and hippocampus differentiated individuals with better or worse formal math achievement, respectively. Overall, these results suggest that two different brain systems for nonsymbolic numerosity acuity may contribute to individual differences in math achievement and that the contribution of these systems differs across development.
authors.affiliation: Department of Psychiatry, University of California, San Diego, California; Center for Human Development, University of California, San Diego, California; Kavli Institute of Brain and Mind, University of California, San Diego, California.
authors.forename: Frank
authors.initials: F
authors.lastname: Haist
authors.forename: Jarnet H
authors.initials: JH
authors.lastname: Wazny
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Toomarian
authors.forename: Maha
authors.initials: M
authors.lastname: Adamo
mesh_terms: D000124:Achievement; D000293:Adolescent; D000328:Adult; D001921:Brain / Q000254:growth & development* / Q000502:physiology*; D001931:Brain Mapping; D002648:Child; D002657:Child Development / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D004522:Educational Status; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D055641:Mathematical Concepts; D008433:Mathematics; D011930:Reaction Time; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: academic achievement; adolescent development; behavior; child development; cognition; functional magnetic resonance imaging; mathematics; number sense; numerosity