An ancient brain circuit, which enables the eyes to reflexively rotate up as the body tilts down, tunes itself early in life as an animal develops, a new study finds.

Led by researchers at NYU Grossman School of Medicine, the study revolves around how vertebrates, which include humans and animals spanning evolution from primitive fish to mammals, stabilize their gaze as they move. To do so, they use a brain circuit that turns any shifts in orientation sensed by the balance (vestibular) system in their ears into an instant counter-movement by their eyes.

The research is published in the journal Science.