Abstract
We explored the development of infants' ability to perceive the 3-D shape of an object from pictorial depth cues, using a “transfer-across-depth-cues” method. Our participants were habituated to a 3-D shape, specified by one cue, and then presented with the same shape and a novel-shape, both specified by a different depth cue. Under these circumstances, infants would show a greater preference for the novel shape rather than the familiar one only if they perceived the shapes from the pictorial depth cues and transferred this information across the cues. In this study, we examined the ability of infants to transfer habituation between shading and line-junction cues which uniquely determined the 3-D shape of a display such that it was shaped either as a slice of cake with a flat top or a rocket that came to a conical point. When the display is presented without either cue, the shape of the object is ambiguous. Our results indicated that six- to seven-month-old infants showed a significant novelty preference despite the change in the pictorial cue that specified the shape. On the other hand, four- to five-month-olds did not. A control experiment showed that the younger infants could discriminate between two displays when a single depth cue specified the two different shapes. These results are similar to our previous findings, which indicated that six- to seven-month-old infants show transfer across shading and surface-contour cues, specifying convex and concave surfaces (Tsuruhara et al, 2009). These two studies suggest that the development of a single mechanism may underlie the emerging ability of infants to form representations of surface layout and of object shape from various pictorial depth cues.
This research was supported by PRESTO-JST and a Grant-in-Aid for Scientific Research (21243041, 20539004) from Japan Society for the Promotion of Science.