Reduced dependence on sensorimotor processing in the brain is associated with higher math skills in adults

Number processing is crucial for math competence, yet the neural underpinnings remain unclear. In this study, we used functional magnetic resonance imaging (fMRI) to 1) identify key brain regions involved in symbolic and embodied number processing, and 2) examine their relations with math abilities in adults and children. We collected fMRI data from 104 adults (Mage = 23.25 yr) and 88 4th graders (Mage = 9.75) as they performed number comparison and phonological tasks with numeral (symbolic) and hand (embodied) numerical stimuli. Participants' math abilities were assessed using the math subtests of the Woodcock-Johnson Tests of Achievement. Univariate analyses revealed number processing regions in occipital, parietal, and temporal cortices including inferior parietal, sensorimotor, supramarginal, and insular areas. In adults, but not in children, less involvement of sensorimotor processing regions during number compared to phonological processing is associated with enhanced math skills. These findings not only elucidate the neural mechanisms underlying number processing and math abilities but also raise questions about the emphasis on sensorimotor numerical representation in math learning experiences.