Vision

Colour has long been a source of fascination to both scientists and philosophers. In one sense, colours are in the mind of the beholder, in another sense they belong to the external world. Colours appear to lie on the boundary where we have divided the world into ‘objective’ and ‘subjective’ events. They represent, more than any other attribute of our visual experience, a place where both physical and mental properties are interwoven in an intimate and enigmatic way. The last few decades have brought fascinating changes in the way that we think about ‘colour’ and the role ‘colour’ plays in our perceptual architecture. This book provides an overview of the contemporary developments in our understanding of colours and of the relationship between the ‘mental’ and the ‘physical’. With each chapter followed by critical commentaries, the volume presents a lively and accessible picture of the intellectual traditions which have shaped research into colour perception.

This book presents the highly complex subject of vision, focusing on the visual information processing and computational operations in the visual system that lead to representations of objects in the brain. In addition to visual processing, it also considers how visual inputs reach and are involved in the computations underlying a wide range of behaviour, thus providing a foundation for understanding the operation of a number of different brain systems.

The cognitive revolution in the 1950s and 1960s led researchers to view the human mind like a computer—an information-processing system that encodes, represents, and stores information and is constrained by limits on hardware (the brain) and software (learning strategies and rules). The emergence of new behavioral, computational, and neuroscience methodologies, has deeply expanded psychologists' understanding of the workings of the infant, child, and adult mind. One result is that research has focused on the mechanisms of change, over developmental time, in the information-processing mind. This book brings together the recent findings and theories about the origins and early development of the information-processing mind, and provides insight into the future directions in the study of infant perception and cognition. The contributions represent a wide-range of research area in the study of infant perception and cognition, which emphasize the use of diverse methodological techniques to address key questions about development. The chapters demonstrate how the combination of historical perspectives on the information-processing approach to cognition and recent advances in behavioral, computational, and neuroscience approaches to cognition has contributed to our understanding of how abilities ranging from visual attention to face processing to object categorization have developed during infancy. Across this broad range of topics, it is clear that much of our modern understanding of infant perceptual and cognitive development emerges from the foundation of classic information-processing models of development, such as that of Leslie B. Cohen (1991). The recent advances illustrated in this book show how researchers have built on this foundation to uncover the mechanisms that drive developmental change.

These three volumes provide the only detailed review of all aspects of perceiving the three-dimensional world. They deal with all the senses involved in depth perception, although the visual system receives the most extensive treatment. Volume 1 deals with basic mechanisms underlying depth perception. It starts with an outline of the history of visual science from the Greeks to the early 20th century. Psychophysical methods, analytic procedures, and sensory coding and the physiology of the primate visual system are reviewed. An account of the evolution of visual systems is followed by an account of the development of the neural mechanisms of the visual system, with emphasis on development of mechanisms of depth perception. A description of the normal development of sensory and motor functions in humans is followed by an account of how these functions, especially depth perception, are disrupted by visual deprivation in early infancy. The two final chapters provide accounts of visual optics, accommodation, and vergence eye movements.

Volume 2 deals with stereoscopic vision in cats, monkeys and humans. It starts with a review of physiological mechanisms of stereoscopic vision. Stereoscopic vision depends on inputs from the two eyes converging in the visual cortex. The mechanisms of binocular rivalry and of other ways in which binocular images interact are reviewed. The images of objects on the horopter are combined so that corresponding parts are brought into register. Once the images are in register, differences between the images are used to code depth. An account is provided of the nature of these differences, the precision with which they are detected (stereoacuity), and the use to which they are put. Two chapters describe how impressions of depth created by binocular disparity are modified by depth contrast, figure-ground interactions, motion, and attention. The book ends with a review of stereoscopic techniques used to create three-dimensional displays and the practical applications of stereoscopic devices.

This volume deals with all depth-perception mechanisms other than stereoscopic vision. It first deals with the visual depth cues of accommodation, vergence eye movements, perspective, interposition, shading, and motion parallax. Ways in which depth cues interact are discussed. These interactions improve discrimination of depth intervals and motion in depth. They also allow us to perceive constancy of size, shape, and relative depth. Pathologies of visual depth perception are described, including visual neglect, and albinism. An account is given of how visual information is used to guide movements of the hand and of the body. Non-visual mechanisms of depth perception are then described. These include audition, echolocation by bats and marine mammals, electrolocation in electric fish, and thermal organs in snakes. The book ends with an account of mechanisms that animals use in navigation and migration.

This book surveys the study of perceptual expertise in visual object recognition, introducing a variety of questions, research findings, and extant issues that have emerged from recent studies of face, object, and letter recognition. The book also discusses a novel collaborative model, codified as the “Perceptual Expertise Network.” The central idea of this group effort is an emphasis on domain-general principles of high-level visual learning that can account for how different object categories are processed and come to be associated with spatially localized activity in the primate brain. The approach brings together different traditions and techniques critical to cognitive neuroscience, such as psychophysics, human brain imaging, monkey physiology, developmental work, neuropsychological studies, and computational modeling. In 12 chapters, members of the Perceptual Expertise Network and their collaborators review how face perception motivated the study of perceptual expertise with objects, how face expertise develops in children, how different kinds of experience result in different degrees of expertise, and how perceptual expertise can break down in individuals with autism or different forms of deficits in perception. They describe advances and challenges in developing models to account for expertise, including the need to account for competition between different domains of expertise and to specify the functional locus of effects of expertise. They introduce more recent directions in the study of expertise, including research on expertise with letters and research investigating the interactions between perception and conception. Finally, they discuss the difficulties in relating high-level perceptual impairments and brain-based evidence to normal performance.

The human visual system is particularly attuned to and remarkably efficient at processing social cues. We can effectively “read” others' mental and emotional states and make snap judgments about their characters and dispositions, simply by watching them. Given what is clearly a close relationship between vision and social interaction, it has become increasingly clear to social psychologists seeking to understand better the functional and neuroanatomical mechanisms underlying social perception that vision plays a critical role in the development and maintenance of social exchange. Likewise, vision scientists have come to appreciate the profound impact people, as social agents, have had on the visual system, acknowledging just how important it is to consider the socially adaptive functions that system evolved to perform. This book explores the biologically-determined to the culturally-shaped influences on social vision. Four themes emerge. These include: visually mediated attention moderates complex social interactions and plays a critical role in the development of social cognition; visual features perceptually determine categorical thinking and have profound downstream consequences including stereotype activation; perceptual experiences can be directly triggered by visual cues, in which case, visual and social perception are essentially equivalent processes; and social factors exert powerful top-down influences on even low-level visual perception, at some times biasing, while at others fine-tuning perceptual acuity. This book heralds the new field of social vision, and showcases the cutting edge and broadly interdisciplinary research that is currently at its forefront.

Seeing happens effortlessly and yet is endlessly complex. Among the most fascinating aspects of visual perception is its stability and constancy. As we shift our gaze or move about the world, the light projected onto the retinas is constantly changing. Yet the surrounding objects appear stable in their properties. Psychologists have long been interested in the constancies. They have asked questions such as: How good is constancy? Is constancy a fact about how things look, or is it a product of our beliefs and judgments about how things look? How can the contents of visual experience be studied experimentally? Philosophers have long been interested in characterizing visual experience and have become widely interested in the constancies more recently. As psychologists and philosophers have interacted, new questions have arisen: If experience is not as of retinal stimulation (proximal mode), but does not always exhibit constancy (or at least not in all respects), how shall we describe this intermediate state? Also, should we regard any departure from constancy as a failure of the visual system, or might it be a reasonable or adaptive response? In what circumstances is seeing highly conditioned by cognitive factors such as background assumptions, and in what circumstances not? This volume focuses on size constancy and color constancy. It considers methodologies for studying conscious visual perception, efforts to describe visual experience in relation to constancy, what it means that constancy is not always perfect, and the conceptual resources needed for explaining visual experience.