Infants' perception of concavity and convexity of shaded objects

The discriminative sensitivities of 30 4‐month‐old and 30 8‐month‐old infants for concave and convex objects were measured using the preferential‐looking method. Five cylinder‐like objects with different magnitudes of concave or convex shaded surfaces and outline contours were presented to the infants in pairs. The results indicated that the 4‐month‐old infants could discriminate better between object convexities than between object concavities. In contrast, the 8‐month‐old infants were able to equally discriminate between object concavities and object convexities, and their sensitivity to both object concavity/convexity was much higher than that of the 4‐month‐old infants. This difference in the sensitivity to object concavity and convexity suggested that younger and older infants might have differential abilities for cue utilization for recovering object structures.