Download or read book Adaptation to Contrast and Speed written by Markus Antero Hietanen and published by . This book was released on 2008 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contrast Adaptation and Contrast Masking in Human Vision written by Harriet Speed and published by . This book was released on 1995 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatiotemporal Tuning and Contrast Adaptation in Mouse Primary Visual Cortex written by Emily Elizabeth LeDue and published by . This book was released on 2012 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Mice have emerged as a popular model of cortical visual processing due to their genetic manipulability. Compared to traditional animal models of visual processing there is less research describing the visual system of mice. Before we can use the genetic techniques available in mice, we must examine the similarity between their visual processing, and that of common animal models used in vision research. One useful method to characterize the way information about form and motion is processed is to examine the interaction between selectivity for spatial and temporal frequency of sine-wave gratings in a given visual area. In experiment 1, we investigated spatiotemporal tuning in neurons of mouse primary visual cortex (V1). Tuning for stimulus speed can readily be extracted from the spatiotemporal profile of a neuron, and we were interested in whether recently described differences in the degree of speed tuning in mouse V1 and macaque V1 were due to methodology. We confirm that speed tuning is rare in mouse V1, demonstrating a difference between motion processing in the striate cortex of mice and macaques. In experiment 2, we examined the spatiotemporal dependence of contrast adaptation in mouse V1 neurons. Little is known about the underlying cellular mechanisms of contrast adaptation, so the mouse provides an attractive model in which to study this phenomenon. We characterized the spatial and temporal frequency dependence of contrast adaptation in mouse V1 neurons simultaneously using a dynamic contrast ramp. We found that for most mouse V1 neurons there was often a difference between the grating that elicited maximal firing, and the grating where adaptation was most pronounced, such that adaptation was usually stronger at higher spatial frequencies.
Download or read book Effect of Contrast on Human Speed Perception written by and published by . This book was released on 1992 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Webvision written by Helga Kolb and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Motion Aftereffect written by George Mather and published by MIT Press. This book was released on 1998 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Motion perception lies at the heart of the scientific study of vision. The motion aftereffect (MAE) is the appearance of directional movement in a stationary object or scene after the viewer has been exposed to viusal motion in the opposite direction. For example, after one has looked at a waterfall for a period of time, the scene beside the waterfall may appear to move upward when one's gaze is transfered to it. Although the phenomenon seems simple, research has revealed copmlexities in the underlying mechanisms, and offered general lessons about how the brain processes visual information. In the 1990s alone, more than 200 papers have been published on MAE, largely inspired by improved techniques for examining brain electrophysiology and by emerging new theories of motion perception.
Download or read book Effect of Contrast on Human Speed Perception written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is part of an ongoing collaborative research effort between the Life Science and Human Factors Divisions at NASA ARC to measure the accuracy of human motion perception in order to predict potential errors in human perception/performance and to facilitate the design of display systems that minimize the effects of such deficits. The study describes how contrast manipulations can produce significant errors in human speed perception. Specifically, when two simultaneously presented parallel gratings are moving at the same speed within stationary windows, the lower-contrast grating appears to move more slowly. This contrast-induced misperception of relative speed is evident across a wide range of contrasts (2.5-50 percent) and does not appear to saturate (e.g., a 50 percent contrast grating appears slower than a 70 percent contrast grating moving at the same speed). The misperception is large: a 70 percent contrast grating must, on average, be slowed by 35 percent to match a 10 percent contrast grating moving at 2 deg/sec (N = 6). Furthermore, it is largely independent of the absolute contrast level and is a quasilinear function of log contrast ratio. A preliminary parametric study shows that, although spatial frequency has little effect, the relative orientation of the two gratings is important. Finally, the effect depends on the temporal presentation of the stimuli: the effects of contrast on perceived speed appears lessened when the stimuli to be matched are presented sequentially. These data constrain both physiological models of visual cortex and models of human performance. We conclude that viewing conditions that effect contrast, such as fog, may cause significant errors in speed judgments. Stone, Leland S. and Thompson, Peter Ames Research Center RTOP 199-16-12-37...
Download or read book Fitting the Mind to the World written by Colin W. G. Clifford and published by Oxford University Press. This book was released on 2005-05-05 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book brings together a collection of studies from international researchers who demonstrate the brain's remarkable capacity to adapt its representation of the visual world in response to changes in its environment."--BOOK JACKET.
Download or read book Neuronal Dynamics written by Wulfram Gerstner and published by Cambridge University Press. This book was released on 2014-07-24 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: This solid introduction uses the principles of physics and the tools of mathematics to approach fundamental questions of neuroscience.
Download or read book Visual Impairments written by National Research Council and published by National Academies Press. This book was released on 2002-08-17 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: When children and adults apply for disability benefits and claim that a visual impairment has limited their ability to function, the U.S. Social Security Administration (SSA) is required to determine their eligibility. To ensure that these determinations are made fairly and consistently, SSA has developed criteria for eligibility and a process for assessing each claimant against the criteria. Visual Impairments: Determining Eligibility for Social Security Benefits examines SSA's methods of determining disability for people with visual impairments, recommends changes that could be made now to improve the process and the outcomes, and identifies research needed to develop improved methods for the future. The report assesses tests of visual function, including visual acuity and visual fields whether visual impairments could be measured directly through visual task performance or other means of assessing disability. These other means include job analysis databases, which include information on the importance of vision to job tasks or skills, and measures of health-related quality of life, which take a person-centered approach to assessing visual function testing of infants and children, which differs in important ways from standard adult tests.
Download or read book The Inferior Colliculus written by Jeffery A. Winer and published by Springer Science & Business Media. This book was released on 2005-12-05 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Connecting the auditory brain stem to sensory, motor, and limbic systems, the inferior colliculus is a critical midbrain station for auditory processing. Winer and Schreiner's The Inferior Colliculus, a critical, comprehensive reference, presents the current knowledge of the inferior colliculus from a variety of perspectives, including anatomical, physiological, developmental, neurochemical, biophysical, neuroethological and clinical vantage points. Written by leading researchers in the field, the book is an ideal introduction to the inferior colliculus and central auditory processing for clinicians, otolaryngologists, graduate and postgraduate research workers in the auditory and other sensory-motor systems.
Download or read book The Effects of Adaptation on the Temporal Response of the Cardinal Color Systems written by Laura A. Baldwin and published by . This book was released on 2002 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines the temporal properties of human color vision in two different ways: 1)compare the temporal sensitivity responses of two parallel color vision channels (the S system and the L-M system), and 2) compare the speed of visual recovery from uniform and contrast adaptation within one of these channels (the L-M system).
Download or read book Visual Perception written by Lothar Spillmann and published by Elsevier. This book was released on 2012-12-02 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an interdisciplinary overview of the main facts and theories that guide contemporary research on visual perception. While the chapters cover virtually all areas of visual science, from philosophical foundations to computational algorithms, and from photoreceptor processes to neuronal networks, no attempt has been made to provide an exhaustive treatment of these topics. Rather, researchers from such diverse disciplines as psychology, neurophysiology, anatomy, and clinical vision sciences have worked together to review some of the most important correlations between perceptual phenomena and the underlying neurophysiological processes and mechanisms. The book is thus intended to serve as an advanced text for graduate students and as a guide for all vision researchers to understanding current progress outside their specialized fields of interest.ï Examines parallel processing of visual informationï Discusses links between physiologically-measured receptive fields and psychophysically-measured perceptive fieldsï Presents a spatial sampling by the retina and cortical modulesï Covers signal transduction and the sites of adaptationï Describes a single-cell analysis of attentionï Discusses computational models of vision
Download or read book Handbook of Visual Optics Volume Two written by Pablo Artal and published by CRC Press. This book was released on 2017-02-24 with total page 937 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Visual Optics offers an authoritative overview of encyclopedic knowledge in the field of physiological optics. It builds from fundamental concepts to the science and technology of instruments and practical procedures of vision correction, integrating expert knowledge from physics, medicine, biology, psychology, and engineering. The chapters comprehensively cover all aspects of modern study and practice, from optical principles and optics of the eye and retina to novel ophthalmic tools for imaging and visual testing, devices and techniques for visual correction, and the relationship between ocular optics and visual perception.
Download or read book The effects of contrast adaptation on contrast matching and discrimination data written by Christina Ann Seay and published by . This book was released on 1994 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptation and Natural Selection written by George Christopher Williams and published by Princeton University Press. This book was released on 2018-10-30 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological evolution is a fact—but the many conflicting theories of evolution remain controversial even today. When Adaptation and Natural Selection was first published in 1966, it struck a powerful blow against those who argued for the concept of group selection—the idea that evolution acts to select entire species rather than individuals. Williams’s famous work in favor of simple Darwinism over group selection has become a classic of science literature, valued for its thorough and convincing argument and its relevance to many fields outside of biology. Now with a new foreword by Richard Dawkins, Adaptation and Natural Selection is an essential text for understanding the nature of scientific debate.
Download or read book Attention and Time written by Kia Nobre and published by . This book was released on 2010 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our ability to attend selectively to our surroundings - taking notice of the things that matter, and ignoring those that don't - is crucial if we are to negotiate the world around us in an efficient manner. Several aspects of the temporal dimension turn out to be critical in determining how we can put together and select the events that are important to us as they themselves unfold over time. For example, we often miss events that happen while we are occupied perceiving or responding to another stimulus. On the other hand, temporal regularity between events can also greatly improve our perception. In addition, our perception of the passage of time itself can also be distorted as while we are performing actions or paying attention to different aspects of the environment. Surprisingly, this fascinating and fundamental interplay between ' attention' and 'time' has been relatively neglected in the psychology and neuroscience literatures until very recently. Attention & Time is the first book to address this foundational topic, bringing together several intriguing and hitherto fragmented findings into a compelling and cohesive field of enquiry. The book contains thirty-one critical-review chapters from internationally recognised experts in the field, carefully organised into three stand-alone, yet extensively cross-referenced, themed sections. Each section focuses on distinct ways in which attention and time influence one another. These sections, each encompassing a range of methodologies from classical cognitive psychology to single-cell neurophysiology, provide functionally unifying frameworks to help guide the reader through the many various experimental and theoretical approaches adopted. Section 1 considers variations of attention across time, and explores how attentional allocation is limited by very short or very long intervals of time. Section 2 describes several types of temporal illusion, illustrating how attention can modulate the perception of the passage of time itself. "A watched pot never boils" and, conversely, "time flies when you're having fun" nicely capture the experimental observation that the degree of attention allocated to stimulus timing contributes to its subjective duration. Finally, Section 3 examines how attention can be directed in time, to predictable or expected moments in time, so as to optimise behaviour. Bringing conceptually discrete, yet functionally related, fields of temporal attention research together within a single volume, this book provides a comprehensive overview that will be of value to the interested novice in cognitive neuroscience, whilst also inspiring experts in the field to make, perhaps previously overlooked, links with their own field of research.
