Summary: Systems in Development: Motor Skill Acquisition Facilitates
Three-Dimensional Object Completion
Kasey C. Soska and Karen E. Adolph
New York University
Scott P. Johnson
University of California, Los Angeles
How do infants learn to perceive the backs of objects that they see only from a limited viewpoint? Infants'
3-dimensional object completion abilities emerge in conjunction with developing motor skills--
independent sitting and visualmanual exploration. Infants at 4.5 to 7.5 months of age (n 28) were
habituated to a limited-view object and tested with volumetrically complete and incomplete (hollow)
versions of the same object. Parents reported infants' sitting experience, and infants' visualmanual
exploration of objects was observed in a structured play session. Infants' self-sitting experience and
visualmanual exploratory skills predicted looking at the novel, incomplete object on the habituation
task. Further analyses revealed that self-sitting facilitated infants' visual inspection of objects while they
manipulated them. The results are framed within a developmental systems approach, wherein infants'
sitting skill, multimodal object exploration, and object knowledge are linked in developmental time.
Keywords: perceptual development, three-dimensional object perception, exploration, object manipula-
Developmental psychology has a long history of linking
achievements in infants' motor skills with improvements in per-