The chapters in this book are based on papers presented at the 23rd Carnegie Mellon Symposia on Cognition. At this exciting event, speaker after speaker presented new discoveries about infants' visual perception in areas ranging from sensory processes to visual cognition. The field continues to make significant progress in understanding the infant's perceptual world. Several advances have come from the development of new methods for exploring infant perception and cognition that have brought new empirical findings. Advances have also been made in understanding the mechanisms underlying perceptual development. Outstanding examples of this ongoing progress can be seen in the chapters of this volume.