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Can a blind person see? The very idea seems paradoxical. And yet, if we conceive of “seeing” as the ability to generate internal mental representations that may contain visual details, the idea of blind vision becomes a concept worth investigating. This book examines the effects of blindness and other types of visual deficits on the development and functioning of the human cognitive system. Drawing on behavioral and neurophysiological data, it analyzes research on mental imagery, spatial cognition, and compensatory mechanisms at the sensorial, cognitive, and cortical levels in individuals with complete or profound visual impairment. The authors find that the brain does not need eyes to “see.” They address critical questions of broad importance: The relationship of visual perception to imagery and working memory and the extent to which mental imagery depends on normal vision; the functional and neural relationships between vision and the other senses; the specific aspects of the visual experience which are crucial to cognitive development or specific cognitive mechanisms; and the extraordinary plasticity of the brain—as illustrated by the way that, in the blind, the visual cortex may be reorganized to support other perceptual or cognitive functions. In the absence of vision, the other senses work as functional substitutes and are often improved—pointing to the importance of the other senses in cognition.

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.

Although William James declared in 1890, “Everyone knows what attention is,” today, there are many different and sometimes opposing views on the subject. This fragmented theoretical landscape may exist because most of the theories and models of attention offer explanations in natural language or in a pictorial manner rather than providing a quantitative and unambiguous statement of the theory, and focus on the manifestations of attention instead of its rationale. This book develops a formal model of visual attention with the goal of providing a theoretical explanation for why humans (and animals) must have the capacity to attend, and uses the full breadth of the language of computation—rather than simply the language of mathematics—as the formal means of description. The result, the Selective Tuning model of vision and attention, explains attentive behavior in humans and provides a foundation for building computer systems that see with human-like characteristics. The overarching conclusion is that human vision is based on a general purpose processor which can be dynamically tuned to the task and the scene viewed on a moment-by-moment basis. The book offers an overview of attention theories and models, and a description of the Selective Tuning model, confining the formal elements to two chapters and two appendixes. The text is accompanied by more than 100 illustrations in black and white and color; additional color illustrations and movies are available on the book’s website.

The recognition of faces is a fundamental visual function that is important for social interaction and communication. Scientific interest in facial recognition has increased dramatically over the last decade. Researchers in such fields as psychology, neurophysiology, and functional imaging have published more than 10,000 studies on face processing. Almost all of these studies focus on the processing of static pictures of faces; however, little attention has been paid to the recognition of dynamic faces, faces as they change over time—a topic in neuroscience that is also relevant to a variety of technical applications, including robotics, animation, and human–computer interfaces. This book offers an interdisciplinary overview of recent work on dynamic faces from the biological and computational perspectives. The chapters cover a range of topics, including the psychophysics of dynamic face perception, results from electrophysiology and imaging, clinical deficits in patients with impairments of dynamic face processing, and computational models that provide insights about the brain mechanisms for the processing of dynamic faces. The book offers neuroscientists and biologists a reference for designing experiments and provides computer scientists with knowledge that will help them improve technical systems for the recognition, processing, synthesizing, and animating of dynamic faces.

The central aim of this book is to analyse the scientific and philosophical work of Galileo Galilei from the particular viewpoint of his approach to the senses (and especially vision) as a way for acquiring trustworthy knowledge about the constitution of the world. For Galileo the senses are potentially ambiguous. Accordingly, reliable information capable of penetrating the complexity of reality can only be obtained by interpreting the sensory data critically. The philosophical background of Galileo’s attitude to the senses is his awareness that nature has not developed a specific language aimed at communicating with senses generally and human senses in particular. The culture of his age was based mainly on a mechanist approach to the world. In this context, Galileo’s analysis of the senses corresponds closely to a fundamental tenet of modern sensory physiology and psychophysics—the absence in the world of specific sensory signals like sounds, colours, tastes, and odours.

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.

This book explains why and how our visual perceptions are veridical; how they can provide us with an accurate representation of the world “out there.” It explains how this computationally difficult problem was solved by describing how the authors built a machine (a computational model) that sees very much as we do. This has never been done before and nothing remotely like it is available anywhere else. Doing it required a “paradigm shift,” an entirely new way of thinking about visual perception, one that is quite unlike any that has been considered up to now. The book, despite its scientific sophistication, is accessible to a very wide audience because each issue covered in the text is discussed twice, once for the “intuitive” reader and once for the “technical” reader. No equations are included in this book, but technical readers can find them in the authors’ published papers. The book, which contains many helpful demos, tells the story of how the machine was developed and what drove the ideas needed to make it work. This makes it an interesting, even gripping, read. The machine, explained clearly in this book, could have enormous practical and scientific, as well as social/artistic consequences. This book combines a new computational theory of shape perception with an account of the history of the theory's discovery. It tells this story together with all relevant background information including criticisms of it and of opposing theories. This mixture is an unusual way to present a major scientific achievement, but it not only works, it also makes for an exciting read.

Visual illusions cut across academic divides and popular interests: on the one hand, illusions provide entertainment as curious tricks of the eye; on the other hand, scientific research related to illusory phenomena has given generations of scientists and artists deep insights into the brain and principles of mind and consciousness. Numerous thinkers (including Aristotle, Descartes, Da Vinci, Escher, Goethe, Galileo, Helmholtz, Maxwell, Newton, and Wittgenstein) have been lured by the apparent simplicity of illusions and the promise that illusory phenomena can elucidate the puzzling relationship between the physical world and perceptual reality. Over the past thirty years, advances in imaging and electrophysiology have dramatically expanded the range of illusions and enabled new forms of analysis, thereby creating new and exciting ways to consider how the brain constructs the perceptual world. The Oxford Compendium of Visual Illusions is a collection of over one hundred chapters about illusions, displayed and discussed by the researchers who invented and conducted research on the illusions. Chapters include full-color images, associated videos, and extensive references. The book is divided into eleven sections: first, a presentation of general history and viewpoints on illusions, followed by sections on geometric, color, motion, space, faces, and cross-category illusions. The book will be of interest to vision scientists, neuroscientists, psychologists, physicists, philosophers, artists, designers, advertisers, and educators curious about applied aspects of visual perception and the brain.

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.

Vision, more than any other sense, dominates our mental life. Our conscious visual experience of the world is so rich and detailed that we can hardly distinguish it from the real thing. But as Goodale and Milner make clear in their prize-winning book, Sight Unseen, our visual experience of the world is not all there is to vision. Some of the most important things that vision does for us never reach our consciousness at all. In this updated and extended edition of their book, Goodale and Milner explore one of the most extraordinary neurological cases of recent years—one that profoundly changed scientific views on the visual brain. It is the story of Dee Fletcher—a young woman who became blind to shape and form as a result of brain damage. Dee was left unable to recognize objects or even tell one simple geometric shape from another. As events unfolded, however, Goodale and Milner found that Dee wasn‘t in fact blind — she just didn‘t know that she could see. They showed, for example, that Dee could reach out and grasp objects with amazing dexterity – despite being unable to perceive their shape, size, or orientation. Taking us on a journey into the unconscious brain, the two scientists who made this incredible discovery tell the amazing story of their work, and the surprising conclusion they were forced to reach. Written to be accessible to students and popular science readers, this book is a fascinating illustration of the power of the ‘unconscious‘ mind.

This posthumously published book (1982), which influenced a generation of brain and cognitive scientists, inspiring many to enter the field, describes a general framework for understanding visual perception and touches on broader questions about how the brain and its functions can be studied and understood. This MIT Press edition makes this work available to a new generation of students and scientists. In the author’s framework, the process of vision constructs a set of representations, starting from a description of the input image and culminating with a description of three-dimensional objects in the surrounding environment. A central theme, and one that has had far-reaching influence in both neuroscience and cognitive science, is the notion of different levels of analysis—in the author’s framework, the computational level, the algorithmic level, and the hardware implementation level. Now, thirty years later, the main problems that occupied the author remain fundamental open problems in the study of perception. His book provides inspiration for the continuing efforts to integrate knowledge from cognition and computation to understand vision and the brain.

This book provides the essential facts about how visual information is processed in the brain. The book has 16 chapters. Chapter 1 provides basic information about the methods that are used by investigators to find out how visual information is processed in living organisms. Chapter 2 outlines the brain areas that process visual information and specifies how these areas are interconnected in the mammalian visual system. Chapter 3 describes in detail the structural and functional organization of the retina. Chapter 4 describes the lateral geniculate nucleus. Chapter 5 delineates the manner in which the primary visual cortex, area V1, is organized. Chapter 6 examines the organization and function of higher cortical visual areas. In Chapter 7 the ON and OFF channels that originate in the retina are examined. In Chapter 8 the characteristics and functions of the midget and parasol channels that originate in the retina are examined. Chapters 9, 10, 11, 12, and 13 examine the manner in which color vision is achieved, what the mechanisms are for light adaptation, how information is processed for pattern perception, and how three-dimensional vision and motion information are processed in the brain. In Chapter 14 our perception of illusory effects is examined. In Chapter 15 the manner in which eye movements are controlled is delineated. In the last chapter, Chapter 16, procedures are described for the creation of visual prosthetic devices, a major task given that in the world there are more than 40 million blind individuals.

The book covers the types and stages of nonconscious and conscious visual processing that have been investigated in psychophysical and brain-recording research using methods allowing microtemporal analysis at a resolution ranging from a few tens to a few hundreds of milliseconds. By tying these findings to well known anatomical and physiological substrates of vision, the intent is to present and discuss theoretical and empirical research on conscious and nonconscious vision that will be of relevance to scientists and scholars interested in visual cognition, visual neuroscience, and, more broadly, cognitive science, including that part of the philosophic community that is currently occupied with the problem of the mind–brain interface. The book provides an in-depth integrative review of recent and ongoing and highly active scientific and scholarly research, and it suggests several avenues for future research in these areas. It also provides a well articulated theoretical and an especially detailed empirical base that can shed new light on, and advance philosophic and scholarly discussions of, visual consciousness. The book is therefore intended to impact on a broad a range of researchers interested in visual perception/cognition, and in the visual conscious and unconscious.

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.

Vision is one of the most active areas in biomedical research, and visual psychophysical techniques are a foundational methodology for this research enterprise. Visual psychophysics, which studies the relationship between the physical world and human behavior, is a classical field of study that has widespread applications in modern vision science. Bridging the gap between theory and practice, this textbook provides a comprehensive treatment of visual psychophysics, teaching not only basic techniques but also sophisticated data analysis methodologies and theoretical approaches. It begins with practical information about setting up a vision lab and goes on to discuss the creation, manipulation, and display of visual images; timing and integration of displays with measurements of brain activities and other relevant techniques; experimental designs; estimation of behavioral functions; and examples of psychophysics in applied and clinical settings. The book’s treatment of experimental designs presents the most commonly used psychophysical paradigms, theory-driven psychophysical experiments, and the analysis of these procedures in a signal-detection theory framework. The book discusses the theoretical underpinnings of data analysis and scientific interpretation, presenting data analysis techniques that include model fitting, model comparison, and a general framework for optimized adaptive testing methods. It includes many sample programs in Matlab with functions from Psychtoolbox, a free toolbox for real-time experimental control. Once students and researchers have mastered the material in this book, they will have the skills to apply visual psychophysics to cutting-edge vision science.