This three-year award will support U.S.-Sweden cooperative research in cognitive psychology between Elizabeth S. Spelke of the University of Cornell and Claes von Hofsten of Umea University, Umea, Sweden. The investigators propose to study the early development of knowledge of motion of physical objects through two different, yet parallel sets of experiments: one using looking methods of object identification (Cornell) and the other utilizing predictive reaching methods (Umea). They will investigate infants' knowledge and perception of physical properties of objects such as gravity, inertia, continuity and solidity. Infants will be presented with a fully visible or partly occluded moving object and their responses measured accordingly. The research attempts to answer two questions: how infants' knowledge of the physical world is developed and whether the same knowledge guides their inferences either through visual perception (looking) or physical action (reaching). Dr. Spelke brings to this collaboration her extensive background and work on infants' understanding of physical properties of objects and events. This is complemented by Dr. von Hofsten's expertise in the development of action and perception/action relationships in infants. The proposed experiments could not be conducted without the unique equipment for investigating object-directed reaching in infants which is only available in the Umea laboratory. This cooperative research effort will advance knowledge of two larger issues in cognitive psychology: how humans learn to operate in and understand the physical world.
