Ii. Visualhabituationstudies: Infants’responses to Typical Andscrambledbody Pictures

This series of studies explores the early development of visuo-spatial human body knowledge in infancy. To achieve this, infants’ responses to typical and scrambled human body shapes were tested. As reviewed above, previous work showed that in a preferential looking paradigm, only 18month-olds appeared to discriminate scrambled from typical human body shapes. This pattern is inconclusive, however, because a lack of preference in younger infants is ambiguous with respect to whether they can discriminate the two types of body shapes. The studies reported below utilized habituation procedures in which infants were presented with typical body shapes until habituation was established, then on the test trials scrambled body shapes were presented, to test for discrimination of the two types of body shapes. The habituation studies were designed to incorporate the six typical and six scrambled body shapes used in our previous work. This is because, as noted above, those body shapes were originally created such that they make basic-level cuts in the body part hierarchy, and they control for overall amount of contour as well as for symmetry. Given the results of the visual preference studies, it was hypothesized that 18-month-olds, who preferred scrambled body shapes in the visual preference paradigm, would also discriminate typical and scrambled human body shapes in the habituation paradigm. Younger infants’ performance was not predicted based on previous findings; thus the performance of 12and 15-month-olds, who showed no visual preference for typical or scrambled body shapes, was of particular interest. Typically, habituation procedures have not been used with infants older than 12 months of age. The relatively mature age of the sample and the decision to incorporate the six typical and six scrambled body shapes from previous work, constrained the design of the habituation studies somewhat. In order to get relatively mature, easily bored one-year-olds though the procedure, a minimal habituation paradigm was used whereby infants were