Cortical representations of numbers and nonsymbolic quantities expand and segregate in children from 5 to 8 years of age

Abstract

Number symbols, such as Arabic numerals, are cultural inventions that have transformed human mathematical skills. Although their acquisition is at the core of early elementary education in children, it remains unknown how the neural representations of numerals emerge during that period. It is also unclear whether these relate to an ontogenetically earlier sense of approximate quantity. Here, we used multivariate fMRI adaptation coupled with within- and between-format machine learning to probe the cortical representations of Arabic numerals and approximate nonsymbolic quantity in 89 children either at the beginning (age 5) or four years into formal education (age 8). Although the cortical representations of both numerals and nonsymbolic quantities expanded from age 5 to age 8, these representations also segregated with learning and development. Specifically, a format-independent neural representation of quantity was found in the right parietal cortex, but only for 5-year-olds. These results are consistent with the so-called symbolic estrangement hypothesis, which argues that the relation between symbolic and nonsymbolic quantity weakens with exposure to formal mathematics in children.

Integrated number sense tutoring remediates aberrant neural representations in children with mathematical disabilities

“…The first five volumes of each time-series were discarded to allow for signal equilibration. The preprocessing pipeline included realignment, slice-timing correction, coregistration to subjects’ T1 and normalization to a 2mm adult Montreal Neurological Institute (MNI) template, similar to a standard practice in neuroimaging research with children (Cantlon et al, 2006; Kersey & Cantlon, 2017; Nakai et al, 2023; Perrachione et al, 2016), and smoothing using a 6mm full-width half-maximum Gaussian kernel to decrease spatial noise. Transitional ( x , y , z ) and rotational (pitch, roll, yaw) movement parameters were generated from the realignment procedure.…”

“…Theoretical models suggest that in typically developing (TD) children, the early stages of learning to associate concrete objects with abstract numerical symbols aid in symbolic numerical problem-solving (Honore & Noel, 2016; Robinson et al, 2002). Interestingly, as TD children gain proficiency, a reverse trend known as “symbolic estrangement” may occur, characterized by distinct neural representations for different number formats (Bulthé et al, 2018; Lyons et al, 2012; Nakai et al, 2023; Schwartz et al, 2021; Wilkey et al, 2020). However, it remains unclear how this typical progression, from the initial integration to subsequent separation of cross-format numerical representations, is altered in children with MD.…”

“…Specifically, we determined whether cross-format NRS between nonsymbolic and symbolic numbers ( The third objective of our study was to investigate whether INS tutoring alters cross-format similarity in numerical processing and neural representational patterns in children with MD in a different manner from TD children. Based on the symbolic estrangement account (Bulthé et al, 2018;Nakai et al, 2023;Schwartz et al, 2021), we hypothesized that the patterns of tutoringinduced plasticity in children with MD and TD children would follow a nonlinear neurodevelopmental model of cross-format association and dissociation of numbers (Fig 1D). Specifically, we predicted that as children with MD improve their ability to map between nonsymbolic and symbolic numbers through INS tutoring, their cross-format similarity in numerical processing and NRS would increase.…”

Developmental Changes in Nonsymbolic and Symbolic Fractions Processing: A Cross-Sectional fMRI study

“…For our multivariate ROI analysis, all images went through different pipelines using SPM12 (Ashburner et al, 2014). Functional images were then coregistered to the T1 anatomical image, similar to a standard practice in neuroimaging research with children (Cantlon et al, 2006;Kersey & Cantlon, 2017;Nakai et al, 2023;Perrachione et al, 2016).Coregistered T1 images were spatially normalized to the standard Montreal Neurological Institute (MNI) template space using affine transformation. The resulting transformation parameters were then applied to the functional images, which were then resampled to isotropic voxel-sizes of 2mm.…”