Individual differences in numerical and mathematical abilities:

A cognitive neuroscience perspectiveDaniel Ansari

Numerical Cognition LaboratoryDepartment of Psychology & Program in Neuroscience

University of Western Ontario

Educational Neuroscience: An Emerging Discipline, Centre for Educational NeuroscienceBirkbeck College, 23-24th June 2010

Why study mental arithmetic?

• Early math skills strong predictor of educational achievement (Duncan et al., 2007)

• International comparison studies reveal ‘achievement gap’

• Health numeracy

• Many children & adults present with ‘Developmental Dyscalculia’

• Large individual differences

Background & Aims

• Background:– Adult neurocognitive models dominate current theorizing

and empirical work – Often focus on group studies with adults

• Aims:– Highlight the importance of considering roles of:

• Development• Individual Differences

– Considering these factors - crucial for emerging field of Educational Neuroscience

Neural correlates of mental arithmetic

Mental Arithmetic LEFT TEMPORO-PARIETAL CORTEX

(e.g. Gerstman, 1940; Roland & Friberg, 1985; Dehaene et al., 1996, 1999)

Evidence from AdultsFunctional Brain Imaging

Meta-analysis by Dehaene et al. (2003)

Are the neural correlates of mental arithmetic modulated by

mathematical competence?

Mental Arithmetic • Screened a large sample of adults (138)

• Selected individuals who did not differ in IQ but varied in their mathematical competence

• fMRI study

• Multiplication verification

Which brain regions activated during multiplication correlated with mathematical competence?

4 x 6 = 24

Grabner, Ansari et al. (2007)

Mental Arithmetic

Grabner, Ansari et al. (2007)

Relationship between AG activation and indiv. difference in Math Competence

Effect of arithmetic strategy choice on brain activation?

Strategy Variability Evidence from Brain Imaging

Are different brain regions involved in

procedural vs. retrieval strategies? – 28 adults

– fMRI study

– During scan : arithmetic problems– Post-scan: strategy self-reports

Comparison between trials for which retrieval vs. procedural strategies were indicated

Strategy Variability Evidence from Brain Imaging

Grabner, Ansari et al. (2009)

Neural correlates of mental arithmetic

Developmental Changes?

Mental Arithmetic

Rivera et al. (2005)

8-19 year olds

EXPERIMENTAL TASK

CONTROL TASK

Mental Arithmetic

Rivera et al. (2005)

Age-related increases in Activation

Age-related decreases in Activation

Mental Arithmetic

Rivera et al. (2005)

• Age-related decreases in the activation of the hippocampus

• Formation of arithmetic facts?• Dynamic relationship between left hippocampus & angular

gyrus in encoding & retrieval of arithmetic facts?

Mental Arithmetic• Protracted developmental trajectory?

• Different neural mechanisms subserving retrieval in adults and children?

Left hippocampusSingle > Multi-digit

(De Smedt, Holloway & Ansari, in prep)

Left Angular GyrusSingle > Multi-digit

(Grabner, Ansari et al. 2007)

ADULTSCHILDREN

Individual Differences & Chronological Age

Strategy-related activationGrabner, Ansari et al. (2009)

Dev. changes in activation Rivera et al. (2005)

Conclusions• Brain mechanisms underlying mental arithmetic are

modulated by:– Development – Individual Differences in Competence – Individual Differences in Strategy Use

• Considering these factors is important for educational neuroscience: – Adult studies insufficient for understanding brain

networks involved in learning arithmetic – Reveals brain networks likely modulated by education

Future Directions • Directly investigate the effects of math instruction

on brain function – Training studies exist with adults but not children– Comparing different educational approaches – E.g. concepts vs. procedures (drill vs. strategy)

• Atypical functioning in children with mathematical difficulties?

• Effects of remediation? – How do different training programs change the neural

circuitry underlying mental arithmetic?

Thank you for your attention!Funding

Collaborators & Students: Roland Grabner

Ian Holloway Lucia van Eimeren

Bert DeSmedt Gavin Price

Stephanie Bugden Bruce McCandliss

Sumit Niogi