Object Perception in Infancy: Interaction of Spatial and Kinetic Information for Object Boundaries

Infants' perception of object boundaries was studied using reaching and preferential looking methods. In 3 reaching studies, S-month-old infants viewed 2 adjacent or separated objects that were stationary, moved together, or moved separately. Infants reached for the objects as distinct units when they moved separately or were separated in space and otherwise reached for the objects as 1 unit. In the looking study, 3-month-old infants were habituated to adjacent or separated objects alternately moving together and separately and were then tested with objects in the other spatial relationship. Patterns of dishabituation provided further evidence that separated or separately moving objects were perceived as distinct units. Infants appear to analyze surface arrangements and motions to form spatially connected bodies that move as wholes. This tendency may stem from an initial conception of the physical world.