Psychophysical Analysis of Visual Space focuses on the use of psychophysics in the analysis of visual space, with emphasis on space perception and physiological optics. Topics covered include null-size judgment, ratio-size judgment, frontal-size judgment, and distance judgment, as well as selected physiological correlates of size and distance judgments. A theoretical analysis of model reduction is also presented. This volume consists of 11 chapters and opens with an overview of basic definitions and evidence in support of the constancy hypothesis. A psychophysical approach to the problems of visual space is described. The reader is then introduced to null-size judgment, ratio-size judgment, frontal-size judgment, and distance judgment, with emphasis on the importance of the retina as a reference for spatial judgments and how size judgments of targets at different distances can be related to judgments of targets at a constant distance. Some of the important relationships between ocular physiology and size-distance judgments are also examined, paying particular attention to size and distance judgments which relate to the variables of convergence, accommodation, angle-of-regard, and binocular disparity. The remaining chapters look at two stimulus correlates of distance judgments: frontal size and longitudinal size. This book will be of interest to physiologists, physicists, and experimental psychologists.

When most people think of space, they think of physical space. However, visual space concerns space as consciously experienced, and it is studied through subjective measures, such as asking people to use numbers to estimate perceived distances, areas, angles, or volumes. This book explores the mismatch between perception and physical reality, and describes the many factors that influence the perception of space including the meaning assigned to geometric concepts like distance, the judgment methods used to report the experience, the presence or absence of cues to depth, and the orientation of a stimulus with respect to point of view. The main theme of the text is that no single geometry describes visual space, but that the geometry of visual space depends upon the stimulus conditions and mental shifts in the subjective meaning of size and distance. In addition, The Geometries of Visual Space: *contains philosophical, mathematical, and psychophysical background material; *looks at synthetic approaches to space perception including work on hyperbolic, spherical, and Euclidean geometries; *presents a meta-analysis of studies that ask observers to directly estimate size, distance, area, angle, and volume; *looks at the size constancy literature in which observers are asked to adjust a comparison stimulus to match a variety of standards at different distances away; *discusses research that takes a multi-dimensional approach toward studying visual space; and *discusses how spatial experience is influenced by memory. While this book is primarily intended for scholars in perception, mathematical psychology, and psychophysics, it will also be accessible to a wider audience since it is written at a readable level. It will make a good graduate-level textbook on space perception.

A comprehensive treatment of the skills and techniques needed for visual psychophysics, from basic tools to sophisticated data analysis. 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.

When most people think of space, they think of physical space. However, visual space concerns space as consciously experienced, and it is studied through subjective measures, such as asking people to use numbers to estimate perceived distances, areas, angles, or volumes. This book explores the mismatch between perception and physical reality, and describes the many factors that influence the perception of space including the meaning assigned to geometric concepts like distance, the judgment methods used to report the experience, the presence or absence of cues to depth, and the orientation of a stimulus with respect to point of view. The main theme of the text is that no single geometry describes visual space, but that the geometry of visual space depends upon the stimulus conditions and mental shifts in the subjective meaning of size and distance. In addition, The Geometries of Visual Space: *contains philosophical, mathematical, and psychophysical background material; *looks at synthetic approaches to space perception including work on hyperbolic, spherical, and Euclidean geometries; *presents a meta-analysis of studies that ask observers to directly estimate size, distance, area, angle, and volume; *looks at the size constancy literature in which observers are asked to adjust a comparison stimulus to match a variety of standards at different distances away; *discusses research that takes a multi-dimensional approach toward studying visual space; and *discusses how spatial experience is influenced by memory. While this book is primarily intended for scholars in perception, mathematical psychology, and psychophysics, it will also be accessible to a wider audience since it is written at a readable level. It will make a good graduate-level textbook on space perception.

This highly original and interesting monograph puts forward ideas on visual processing and representation in the early stages of visual perception, and examines the computational requirements of the system and its psychological performance. Initially the author considers the computational theory of how the maximum amount of useful information about the scene can be registered from the variations in light intensity in the retinal image. He then goeson to address the question of just what it means to say that the visual system measures spatial aspects of the retinal image, and the consequences of the inevitable distortions that are introduced. He believes that the calculation of spatial position within a distorted metric is not trivial and requires dynamic processes with memory and control. Finally, Dr. Wan argues that the strength of the link between the low-level approaches of psychophysics and computational theory and high-level approaches of cognitive visual function lies in the logic of the arguments that indicate the computational need for control. This Essay will be of great interest to researchers in computer vision, perception, cognitive science and cognitive psychology.

This special issue examines the basic processes of space perception and how these processes interact with action planning and motor control.