This paper reviews progress over the past 20 years in four areas of research on infant perception and cognition. Work on perception of dynamic events has identified perceptual constraints on perception of object unity and object trajectory continuity that have led to a perceptual account of early development that supplements Nativist accounts.…

When an object moves behind an occluder and re-emerges, 4-month-old infants perceive trajectory continuity only when the occluder is narrow, raising the question of whether time or distance out of sight is the important constraining variable. One hundred and forty 4-month-olds were tested in five experiments aimed to disambiguate time and distance…