Cortical recycling in high-level visual cortex during childhood development

Human ventral temporal cortex (VTC) contains category-selective regions that respond preferentially to ecologically-relevant categories such as faces1, bodies2, places3, and words4 and are causally involved in the perception of these categories5-7. However, it is unknown how these regions develop during childhood. Here we used functional MRI and images from many categories to measure longitudinal development of category-selectivity in individual school-age children over the course of 5 years. We show that from young childhood to the teens, face- and word-selective regions in VTC expand and increase in their respective category-selectivity, but limb-selective regions in VTC shrink and lose their preference for limbs. Critically, as a child develops, increases in their face- and word-selectivity are directly linked to decreases in limb-selectivity. These data show that during childhood limb-selectivity in VTC is repurposed into word- and face-selectivity providing the first empirical evidence for cortical recycling8 during childhood development. These results suggest a rethinking of prevailing hypotheses that cortical development involves sculpting of new representations upon general-purpose cortex9,10. Instead, they suggest a new hypothesis that during development VTC representations adjust to changes in the salience and social relevance of visual inputs11, which has important implications for both typical and atypical brain development.