Human vision maintains a rich representation of objects moving behind an occluder

Vision may seem continuous, but it is frequently disrupted, by internal processes, such as blinks and fast eye-movements, and by external foreground clutter obscuring background objects. Yet when a bicycle passes behind a bush, we maintain a strong sense that it has not vanished, but persists, continuing its unseen motion. Using an indirect probe technique, we show that the visual system maintains, for at least 1 s, a rich perceptual representation of objects moving behind occluders. We created the impression of two disks moving behind a visible occluder, and after 1 s participants judged the colour of a probe disk flashed briefly between their virtual trajectories. The perceived colour of the test was strongly biased towards that of the inducers, showing colour assimilation. Our results show that the visual system maintains, at an early perceptual level, a relatively rich representation of temporally occluded objects, mapping their spatio-temporal trajectories, and storing information about sensory properties such as colour.