Development of motion perception in early infancy.

This article summarizes some research on the development of motion perception in early infancy. The sensitivity for slow and rapid motion was studied with 1-month-old and 3-month-old babies. The findings suggest that there are different developmental courses for the detection of slow and rapid motion. The ability to detect very slow motion seems to improve gradually with age whereas the sensitivity for very rapid motion seems to be at a level comparable to adults soon after birth. Three-month-old babies do use kinetic visual information in order to perceive object boundaries and form. After having seen a form visible only when moving they are able to "identify" the same form when seeing it under static conditions. Infants and young children do use kinetic visual information for recognizing figures that are never completely in sight only if they have been familiarized with the fully visible form first. Even 4-year-olds have difficulties in perceiving the full form of a figure that moves behind a slit in an opaque occluding surface if there is no familiarity or "priming" with the global form first. In conclusion, infants are able to detect visual motion very early in life and do extract information which leads to the perception of form. However, this ability may be limited to events with uninterrupted, continuous movement of visible elements.