TRACKING AND ANTICIPATION OF INVISIBLE SPATIAL TRANSFORMATIONS BY 4-MONTH-OLD TO 8-MONTH-OLD INFANTS

The ability of 4- to 8-month-old infants to track and anticipate the f inal orientation of an object following different invisible spatial tr ansformations was tested. A violation-of-expectation method was used t o assess infants' reaction to possible and impossible outcomes of an o bject's orientation after it translated or rotated behind an occluder. Results of a first experiment show that at all ages infants tend to l ook significantly longer at an impossible orientation outcome followin g invisible transformations. These results suggest that from 4 months of age, infants have the ability to detect orientation-specific inform ation about an object undergoing linear or curvilinear invisible spati al transformations. A second experiment controlling for perceptual cue s that infants might have used in the first experiment to track the ob ject orientation replicates the results with a new sample of 4- and 6- month-old infants. Finally, a control experiment involving no motion y ielded negative results, providing further support that infants as you ng as 4 months old use motion information to mentally track invisible spatial transformations. The results obtained in the rotation conditio n of both experiments are tentatively interpreted as providing first e vidence of some rudiments of mental rotation in infancy.