Estimating the duration of perceptual moments from early infancy to adulthood

Although human perception appears continuous, converging evidence suggests that sensory input is integrated over discrete temporal windows. The duration of these Temporal Integration Windows (TIWs) determines the temporal resolution of perception, but how this fundamental property develops across infancy and childhood remains unknown. Here, we estimate TIW duration from 5 months of age to adulthood using a novel, instruction-free eye-tracking paradigm that isolates pre-attentive visual integration. Across four experiments with the same paradigm (N = 308 participants), we measured spontaneous detection of a visual target that emerges only when two alternating displays are integrated within a single perceptual window. We observed a striking developmental shortening of the TIW. In adults and 5-year-olds, integration succeeded at short interstimulus intervals (ISIs; 16-32 ms) but failed at longer intervals (83-116 ms), yielding an estimated TIW of [~]57 ms. At 3 years, the TIW extended to [~]100 ms. In infancy, integration remained robust at substantially longer ISIs, with estimates of [~]250 ms at 18 and 8 months, and [~]400 ms at 5 months. The steepest reduction occurred within the first year of life. These findings reveal an approximately sevenfold acceleration in the temporal resolution of visual perception from early infancy to adulthood. Progressive shortening of TIWs suggests that infants and adults integrate sensory information over fundamentally different temporal scales, with implications for perceptual organization, learning, and neurodevelopmental trajectories.