What accounts for developmental shifts in optic flow sensitivity?

Human infants undergo significant changes in body size, posture, and locomotor capability over the first several years of life. As a result, the statistics of visual motion infant observers experience differs from adults in some situations [1,2]. We ask whether these differences apply more generally, and if so, what factors account for them. In one analysis, we simulate the effects of changes in body posture, speed of locomotion, and surface geometry on motion statistics. In a second analysis, we empirically measure the statistics of visual motion experienced by observers across the first year of life using infant-perspective videos captured during episodes when infants were moving through space or were stationary. We include samples of infants in from North America and those from India to assess how variations in cultural practices influence infants' visual experiences. We find that fast laminar motion patterns dominate the visual input young infants experience and that cultural differences play a role in shaping visual motion experiences.