The study of object category development is a central concern in the field of cognitive science. Researchers investigating visual and auditory perception, cognition, language acquisition, semantics, neuroscience, and modeling have begun to tackle a number of different but centrally related questions concerning the representations and processes that underlie categorization and its development. This book covers a broad range of current research topics in category development. Its aim is to understand the perceptual and cognitive mechanisms that underlie category formation and how they change in developmental time. The chapters in this book are organized around three interrelated themes: (1) the fundamental process by which infants recognize and remember objects and their properties, (2) the contribution of language in selecting relevant features for object categorization, and (3) the higher-level cognitive processes that guide the formation of semantic systems. The volume is appropriate for researchers, educators, and advanced graduate students.