A Quantitative Study Of Achromatic Visual Contrast

The present volume was assembled in honor of Professor Alan Cowey FRS, and attempts to embrace his wide range of research interests in visual neuroscience. It is divided into four sections. The first contains a group of papers dealing with different fundamental aspects of the visual system, including the control and monitoring of eye movements. The second is concerned with the functional organization of cortical visual areas and their role in visual perception and visually guided action. The third addresses issues concerning color and motion perception, along with broader questions of visual attention; and the effects of selective brain damage on these different aspects of visual experience. The fourth and final section of the volume deals explicitly with questions relating to visual awareness, with particular emphasis on 'blindsight', a topic on which Alan Cowey has worked extensively in recent years, both in humans and in monkeys.

Proceedings of the Sixth Symposium of the International Research Group on Colour Vision Deficiencies

Colorimetry: Understanding the CIE System summarizes and explains the standards of CIE colorimetry in one comprehensive source. Presents the material in a tutorial form, for easy understanding by students and engineers dealing with colorimetry. Provides an overview of the area of CIE colorimetry, including colorimetric principles, the historical background of colorimetric measurements, uncertainty analysis, open problems of colorimetry and their possible solutions, etc. Includes several appendices, which provide a listing of CIE colorimetric tables as well as an annotated list of CIE publications. Commemorates the 75th anniversary of the CIE's System of Colorimetry.

How the human visual system determines the lightness of a surface, that is, its whiteness, blackness, or grayness, remains--like vision in general--a mystery. In fact, we have not even been able to create a machine that can determine, through an artificial vision system, whether an object is white, black, or gray. Although the photoreceptors in the eye are driven by light, the light reflected by a surface does not reveal its shade of gray. Depending upon the level of illumination, a surface of any shade of gray can reflect any amount of light. In Seeing Black and White Alan Gilchrist ties together over 30 years of his own research on lightness, and presents the first comprehensive, historical review of empirical work on lightness, covering the past 150 years of research on images ranging from the simple to the complex. He also describes and analyzes the many theories of lightness--including his own--showing what each can and cannot explain. Gilchrist highlights the forgotten-yet-exciting work done in the first third of the twentieth century, describing several crucial experiments and examining the brilliant but nearly unknown work of the Hungarian gestalt theorist, Lajos Kardos. Gilchrists review also includes a survey of the pattern of lightness errors made by humans, many of which result in delightful illusions. He argues that because these errors are not random, but systematic, they are the signature of our visual software, and so provide a powerful tool that can reveal how lightness is computed. Based on this argument and the concepts of anchoring, grouping, and frames of reference, Gilchrist presents a new theoretical framework that explains an unprecedented array of lightness errors. As both the first comprehensive overview of research on lightness and the first unified presentation of Gilchrists new theoretical framework Seeing Black and White will be an invaluable resource for vision scientists, cognitive psychologists, and cognitive neuroscientists.