The Oxford Compendium Of Visual Illusions

Visual illusions are compelling phenomena that draw attention to the brain's capacity to construct our perceptual world. The Compendium is a collection of over 100 chapters on visual illusions, written by the illusion creators or by vision scientists who have investigated mechanisms underlying the phenomena. --

If you find visual illusions fascinating Programming Visual Illusions for Everyone is a book for you. It has some background, some history and some theories about visual illusions, and it describes in some detail twelve illusions. Some are about surfaces, some are about apparent size of objects, some are about colour and some involve movement. This is only one aspect of the book. The other is to show you how you can create these effects on any computer. The book includes a brief introduction to a powerful programming language called Python. No previous experience with programming is necessary. There is also an introduction to a package called PsychoPy that makes it easy to draw on a computer screen. It is perfectly ok if you have never heard the names Python or PsychoPy before. Python is a modern and easy-to-read language, and PsychoPy takes care of all the graphical aspects of drawing on a screen and also interacting with a computer. By the way, both Python and PsychoPy are absolutely free. Is this a book about illusions or about programming? It is both!

Describes a range of exciting new approaches to neuropsychological investigation and provides a broad overview of visual neuropsychology. The book starts by examining the neural basis of perception - presenting important new research using single-unit recordings. It then considers disturbances of visual perception such a agnosia, neglect, blindsight, and achromatopsia, describing what we now know about recovery and rehabilitation from cerebral visual disorders. Throughout, the book refers to new and adapted techniques for measuring brain activity, including multi-unit sum potential recording, fMRI, and transranial magnetic-stimulation. With contributions from leading scientists in the vision sciences, it provides a state-of-the-art review of the topic.

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.

Hallucinations, for most people, imply madness. But there are many different types of non-psychotic hallucination caused by various illnesses or injuries, by intoxication--even, for many people, by falling sleep. From the elementary geometrical shapes that we see when we rub our eyes to the complex swirls and blind spots and zigzags of a visual migraine, hallucination takes many forms. At a higher level, hallucinations associated with the altered states of consciousness that may come with sensory deprivation or certain brain disorders can lead to religious epiphanies or conversions. Drawing on a wealth of clinical examples from his own patients as well as historical and literary descriptions, Oliver Sacks investigates the fundamental differences and similarities of these many sorts of hallucinations, what they say about the organization and structure of our brains, how they have influenced every culture's folklore and art, and why the potential for hallucination is present in us all.

In this ground-breaking synthesis of art and science, Diana Deutsch, one of the world's leading experts on the psychology of music, shows how illusions of music and speech--many of which she herself discovered--have fundamentally altered thinking about the brain. These astonishing illusions show that people can differ strikingly in how they hear musical patterns--differences that reflect variations in brain organization as well as influences of language on music perception. Drawing on a wide variety of fields, including psychology, music theory, linguistics, and neuroscience, Deutsch examines questions such as: When an orchestra performs a symphony, what is the "real" music? Is it in the mind of the composer, or the conductor, or different members of the audience? Deutsch also explores extremes of musical ability, and other surprising responses to music and speech. Why is perfect pitch so rare? Why do some people hallucinate music or speech? Why do we hear phantom words and phrases? Why are we subject to stuck tunes, or "earworms"? Why do we hear a spoken phrase as sung just because it is presented repeatedly? In evaluating these questions, she also shows how music and speech are intertwined, and argues that they stem from an early form of communication that had elements of both. Many of the illusions described in the book are so striking and paradoxical that you need to hear them to believe them. The book enables you to listen to the sounds that are described while reading about them.