LAUSR

Significance This study reports the discovery that large-scale topographic maps of the body exist throughout the entire primate somatosensory and motor systems at birth. Our results suggest that this proto-organization is established prenatally, even in areas that are crucial for coordinating and executing complex, ethologically relevant actions in adults. Given the behavioral immaturity of neonates, this suggests that large-scale body maps precede these action domains. Furthermore, our data can explain how these domains arise in stereotypical locations without the need for prespecification of function. This study demonstrates that topographic representations are a fundamental and pervasive principle of early development, providing the protoarchitecture of the entire brain on which experience-dependent specializations are elaborated postnatally. Topographic sensory maps are a prominent feature of the adult primate brain. Here, we asked whether topographic representations of the body are present at birth. Using functional MRI (fMRI), we find that the newborn somatomotor system, spanning frontoparietal cortex and subcortex, comprises multiple topographic representations of the body. The organization of these large-scale body maps was indistinguishable from those in older monkeys. Finer-scale differentiation of individual fingers increased over the first 2 y, suggesting that topographic representations are refined during early development. Last, we found that somatomotor representations were unchanged in 2 visually impaired monkeys who relied on touch for interacting with their environment, demonstrating that massive shifts in early sensory experience in an otherwise anatomically intact brain are insufficient for driving cross-modal plasticity. We propose that a topographic scaffolding is present at birth that both directs and constrains experience-driven modifications throughout somatosensory and motor systems.