In recent years, significant, indeed dramatic, advances have occurred in the study of perception. These have been made possible by, and, in fact, in- clude methodological advances such as the development of signal detection theory and the application of linear systems analysis to auditory and visual per- ception. They are reflected in an interest in the study of ecologically valid perceptual problems, e. g., control of locomotion, speech perception, reading, perceptual-motor coordination, and perception of events. At the same time, exciting new insights have been gained to some of the classical problems of perception-stereoscopic vision, color vision, attention, position constancy, to mention a few. A broad, comparative approach to perception has also been taken. This approach, which includes the detailed study of human infant per- ception as well as cross-cultural and cross-species investigations, has given us a very broad perspective of the perceptual process. In this context, the present volume inaugurates a new series entitled' 'Per- ception and Perceptual Development: A Critical Review Series. " The editors are particularly gratified by the enthusiastic support for their ideas by Seymour Weingarten of Plenum Press. He and the editorial staff of Plenum Press have been of immense help in initiating the series as well as helping with the details of this first volume.