Typical and Atypical Development of Basic Numerical Magnitude Representations: A Review of Behavioral and Neuroimaging Studies

In their seminal work on children’s development of number concepts, Robbie Case and his collaborators emphasized the importance of having a firm understanding of numerical quantity for children’s development of mathematical competencies. Since Case’s work on number competencies in children, work in cognitive psychology and cognitive neuroscience has made much progress in our understanding of how numerical magnitude is processed and what neural mechanisms are associated with the representation of numerical quantity. Such research has revealed that even young infants appear to have rudimentary representations of numerical magnitude, but that these undergo qualitative changes over the course of learning and development and that the associated neural correlates undergo ontogenetic changes. Moreover, recent data suggest that children with developmental difficulties in learning mathematics (such as “Developmental Dyscalculia”) exhibit difficulties in processing numerical magnitude. Furthermore, consistent with Case’s notion of the critical importance of numerical magnitude processing skills, individual differences in numerical quantity processing have recently found to be associated with variability in children’s math scores. In the present chapter, we review the available behavioral and brain-imaging evidence on the development of numerical quantity and discuss the educational implications of the available data.