Perception of surface glossiness by infants aged 5 to 8 months.

We examined glossiness perception in infants using a preferential looking paradigm. In experiment 1, the images of two doll-shaped objects with matte and glossy surfaces were presented to infants aged 5 to 6 and 7 to 8 months. The results showed that the 7 to 8 month olds, but not the 5 to 6 month olds, looked significantly longer at the glossy object than at the matte object. In experiment 2, we additionally employed an object that was matte and covered with textures of white paint splashes, whose luminance histogram was almost identical to that of the glossy object. The results showed that the 7 to 8 month old infants could discriminate between the glossy object and the textured object even though both had similar luminance histograms. Qualitatively similar results were obtained for simple spheres that did not contain facial features. Therefore, the results of experiments 1 and 2 were not due to differences in the visibility of the dolls' facial features. These findings suggest that 7 to 8 month old infants perceive difference between glossy objects and matte objects on the basis of surface representations.