Infant sensitivity to trajectory forms

The authors investigated whether infants are sensitive to visual event traj ectory forms, and whether they are sensitive to the underlying dynamics of trajectory forms. The authors habituated 8-month-old infants to a videotape d event run either forward or reversed in time and then switched them to th e same event run in the opposite direction. Infants dishabituated when swit ched to the event with the novel direction in time, indicating sensitivity to the form of the trajectory. Infants exhibited equivalent habituation rat es and looking times for forward and reversed events, thus failing to provi de evidence that infants are sensitive to the underlying dynamics. In a par tial replication of this first experiment, the same pattern of results was found. Both experiments revealed infant sensitivity to the trajectory forms , but not the underlying dynamics of events. The authors discuss implicatio ns for methods used in infant event perception studies.