Behavioral signatures of a developing neural code

During early life neural codes must develop to appropriately transform sensory inputs into behavioral outputs. Here we demonstrate a direct link between the maturity of neural coding in the visual brain and developmental changes in visually-guided behavior. In zebrafish larvae we show that visually-driven hunting behavior improves from 4 to 15 days post-fertilization, becoming faster and more accurate. During the same period population activity in the optic tectum refines, leading to improved decoding and information transmission of spatial position, particularly in the representation of the frontal visual field. Remarkably, individual differences in decoding can predict each fish’s hunting success. Together these results show how the neural codes required to subserve a natural behavior emerge during development.