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Why We See What We Do Redux

A Wholly Empirical Theory of Vision

Dale Purves and Beau R. Lotto

Publication Date - 05 November 2010

ISBN: 9780878935963

262 pages
7 x 9 inches

In Stock

Encourages readers to consider the concept of vision and its implications for interpreting, modeling, and ultimately understanding the structure and function of the human visual system


The First Edition of this provocative book reviewed a broad range of evidence leading to the conclusion that the visual system does not reveal the physical world by an analysis of retinal images and their representation by the visual system. Rather, what we see is based on the history of the species and the individual as a means of contending with the inherent uncertainty of light stimuli. It follows that visual perceptions are reflexive manifestations of past behavioral success rather than the result of a logical processing of present stimuli.

These ideas were met with considerable skepticism. To quote from the preface of this new edition:

"Although the ideas and evidence about the genesis of what we see in the First Edition were appreciated in some quarters, the reception in others was distinctly cool. Given the opinion of some critics that the wholly empirical concept of vision we proposed was either unbelievable or incomprehensible, we felt duty bound to try again. Our objective was, and remains, to present a different and seemingly inevitable framework for understanding perception and its underlying neural mechanisms. We hope this new edition will encourage more readers to consider this concept of vision and its implications for interpreting, modeling, and ultimately understanding the structure and function of the human visual system."

This refinement and expansion of the argument in the First Edition, supported with much new evidence gathered over the last seven years, has far-reaching consequences not only for understanding vision but brain function generally.

The book is written in a way that is understandable by individuals with little or no background in neuroscience, with chapter introductions and summaries that make the overall argument easy to follow. The book includes over 400 bibliographic citations, a complete glossary, and a primer on the organization of the visual system as an appendix.

About the Author(s)

Dale Purves is Professor in the Departments of Neurobiology, Psychology, and Brain Sciences, and Philosophy at Duke University. After earning a B.A. from Yale, an M.D. from Harvard Medical School, and completing an assistant residency at Massachusetts General Hospital, Dr. Purves was a postdoctoral fellow in the Department of Neurobiology at Harvard Medical School and subsequently in the Department of Biophysics at University College London. He joined the faculty at Washington University School of Medicine in 1973, where he was Professor of Physiology and Biophysics, and came to Duke as the founding chair of the Neurobiology Department in 1990. From 2003 to 2009 he was Director of Duke's Center for Cognitive Neuroscience. Dr. Purves is now Director of the Neuroscience and Behavioral Disorders Program of the Duke's Graduate Medical School in Singapore. His research in recent years has sought to explain why we see and hear what we do. He was elected to the National Academy of Sciences in 1989 for his work on neural development and synaptic plasticity, and is a member of the American Academy of Arts and Sciences and the Institute of Medicine.

R. Beau Lotto is a Reader of Neuroscience at University College London. He received his undergraduate degree at the University of California, Berkeley and a Ph.D. from the University of Edinburgh. Dr. Lotto's work spans studies of bees, humans, and machines that have led to public work installations and interactive/participatory performances. He has lectured on perception for general audiences in the Technology, Entertainment, and Design (TED) series, the RSA series, and the BBC. His "Street Science" installations include a six-meter colored-glass tower called the Beacon on Old Street in London (see the book cover), an installation of light, glass, and bees for the Science Gallery in Dublin, and "White Shadows," an installation for the Hayward Gallery. Current projects include a perception-based education program for primary schools in the UK, a Glass Windmill for the Wellcome Trust, and the Vertical Orchestra with the London Sinfonietta. He is now launching a new Centre of Perception at London's Science Museum, a research space that enables the public to be active participants and creators of scientific research. All these projects explore the ecological basis of the mind in the context of understanding why we see what we do.


"In their book, Purves and Lotto present a nontraditional perspective on understanding visual perception. It is comprehensive and provocative, and perhaps most important, provides a critical review of approaches to understanding visual perception that are based on the processing of representations or images. As a result, it is worth reading, especially by researchers who would like to reverse the trend of perception being given short shrift in vision research. One of the great strengths of the approach that Purves and Lotto develop is that it is consistent with recent theories of evolution and learning that stress the plasticity of the nervous system."--Jeffrey B. Wagman, PsycCRITIQUES

Table of Contents

    1. Vision and Visual Perception

    2. Seeing Lightness and Brightness

    3. Seeing Color

    4. Seeing Intervals, Angles, and Object Sizes

    5. Seeing Distance and Depth

    6. Seeing Motion

    7. Making Sense of the Visual System in Empirical Terms

    Appendix. A Primer on Visual System Structure and Function

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