The development of infants' perception of object movement along inclines

Three experiments investigated 10- and 16-month-old infants' perceptions of events involving a computer-generated ball rolling up or down an incline. Experiment 1 demonstrated that infants do not have a priori preferences for either impossible or possible events. In Experiments 2 and 3, infants were habituated to either a possible or an impossible event and then shown thre e novel events that involved changes in individual features that may or may not correspond to changes in possibility. Ten-month-old infants responded to changes in individual features when habituated to downward movement and did not discriminate among any changes when habituated to upward movement. Sixteen-month-old infants responded to possibility changes that were accomp anied by a change in direction when habituated to downward movement, and re sponded to changes in individual features when habituated to upward movemen t. These findings are discussed in terms of a framework by which infants fi rst attend to individual features in events and later respond on basis of t he combination of those features.