Tracking and anticipation of invisible spatial transformations by 4- to 8-month-old infants

The ability of 4- to 8-month-old infants to track and anticipate the final orientation of an object following different invisible spatial transformations was tested. A violation-of-expectation method was used to assess infants' reaction to possible and impossible outcomes of an object's orientation after it translated or rotated behind an occluder. Results of a first experiment show that at all ages infants tend to look significantly longer at an impossible orientation outcome following invisible transformations. These results suggest that from 4 months of age, infants have the ability to detect orientation-specific information about an object undergoing linear or curvilinear invisible spatial transformations. A second experiment controlling for perceptual cues that infants might have used in the first experiment to track the object orientation replicates the results with a new sample of 4- and 6-month-old infants. Finally, a control experiment involving no motion yielded negative results, providing further support that infants as young as 4 months old use motion information to mentally track invisible spatial transformations. The results obtained in the rotation condition of both experiments are tentatively interpreted as providing first evidence of some rudiments of mental rotation in infancy.