The Influence of Contexton Amodal Completion in 5- and 7-Month-Old Infants

Abstract

Several investigations have shown that young infants perceive the unity of a center-occluded object when the visible ends of the object undergo common motion but not when the object remains stationary. This study is an extension of earlier investigations on object unity in that it assesses amodal completion of stationary circles in which one half of each is covered by a block. As the experimental stimuli were depicted in the picture plane, only pictorial depth placement cues were available. Furthermore, by employing a stimulus display reported by Palmer (e.g., Palmer, Neff, & Beck, 1996), the role of contextual cues on the perception of the target elements' shape was examined. Results indicated that participants 7 months of age were able to amodally complete the target surfaces if all context elements were full circles. Five-month-old participants, on the other hand, failed to exhibit a comparable visual performance. For them, the most unambiguous situation was one in which the context elements were semicircles. Here, the infants apparently interpreted the target elements to be semicircles as well. The findings suggest that 7-month-olds perceive depth from occlusion cues and are able to use local and global shape completion cues. Younger infants are capable of utilizing contextual shape information, but they apparently fail to conduct amodal completion.