Perceptual categorization of cat and dog silhouettes by 3- to 4-month-old infants

Given evidence that silhouette information can be used by adults to form categorical representations at the basic level, four experiments utilizing the familiarization-novelty preference procedure were performed to examine whether 3- and 4-month-old infants could form categorical representations for cats versus dogs from the perceptual information available in silhouettes (e.g., global shape and external outline). Experiments 1 and 2 showed that infants could form individuated categorical representations for cat and dog silhouettes, whereas Experiments 3 and 4 revealed that infants could use silhouette information from the head, but not the body, to categorically separate the two species. These results indicate that general shape or external contour information that is centered about the head is sufficient for young infants to form individuated categorical representations for cats and dogs. The data thus provide information regarding the nature of the perceptual information that can be used by infants to form category representations for individual animal species and are discussed in terms of domain-general versus domain-specific processing accounts.