Schooling shapes the brain: neural specialization for words and numbers in early childhood.

Experience-dependent neuroplasticity refers to the brain’s ability to reorganize in response to experience. An intriguing example occurs when children begin formal schooling, acquiring skills such as reading and symbolic number processing. Because the human brain is not evolutionarily predestined for these skills, it must adapt by recycling pre-existing cortical systems. Longitudinal fMRI studies have documented substantial functional changes during the ages 5 to 7, including increasing specialization of the left fusiform gyrus for words and the intraparietal sulcus (IPS) for symbolic numbers. However, because these changes coincide with formal school entry, it remains unclear whether these changes are driven by schooling or age. Using a quasi-experimental school cut-off design, we compared two similar-aged groups differing in exposure to formal schooling. Sixty-four children (36 schooling, Med _age = 68.5 months; 28 non-schooling, Med _age = 66 months) were scanned twice, one year apart, during a passive fMRI task involving words and digit sequences. Mixed-effects models in 57 children revealed that increased activation for words in the left fusiform gyrus and left supplementary motor area, and increased activation for numbers in the right inferior parietal cortex, occurred only in children who attended first grade. These findings indicate that schooling, beyond age, drives functional specialization for words and numbers.