Recent advances in the study of visual cognition and consciousness have dealt primarily with steady-state properties of visual processing, with little attention to its dynamic aspects. The First Half Second brings together for the first time the latest research on the dynamics of conscious and unconscious processing of visual information, examining the time-course of visual processes from the moment a stimulus is presented until it registers in a behavioral response or in consciousness a few hundred milliseconds later. The contributors analyze this "first half second" of visual processing -- known as its microgenesis -- from a variety of perspectives, including neuroscience, neuropsychology, psychophysics, psychology, and neural network modeling.The book first treats conceptual, methodological, and historical issues and provides an integrated review of findings from recent studies on the neural underpinnings of consciousness. The book then turns to neurophysiological correlates of dynamic processing in vision, highlighting the temporal dimension of functional distinctions; visual masking and what it can tell us about the operation of both normal and abnormal brains; the dynamics of attentional mechanisms from electrophysiological, behavioral, and modeling perspectives; and temporal characteristics of object and feature perception. Finally, drawing on the foundations laid in earlier chapters, the book elaborates further on the dynamic relation of conscious and unconscious processes in vision. The First Half Second fills the need for an interdisciplinary dialogue on the study of the dynamic aspects of visual processing and, with its rich empirical and theoretical findings, charts promising directions for future research.