Download or read book Perceptual Processes Underlying Depth Judgements of Moving Objects During Self motion written by Ranran L.. French and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An important function of the visual system is to represent the 3D structure of the world from the sequence of 2D images projected onto the retinae. During observer translation, relative image motion between stationary objects at different distances (motion parallax, MP) provides potent depth information. However, if an object is moving relative to the scene, this complicates the computation of depth from MP since there will be an additional component of image motion related to object motion. To correctly compute depth from MP, this component should be ignored by the brain. Previous experimental and theoretical work on depth perception from MP has assumed that objects are stationary in the world. How the brain perceives depth of moving objects based on motion parallax has not been examined. This dissertation investigates the perception of depth for moving objects during self-motion in human subjects. First, we ask if human subjects can accurately judge depth of moving objects. Six human subjects were asked to judge the depth of an object relative to the plane of fixation while lateral self-motion was simulated by optic flow. We find that subjects show a robust and systematic depth bias that depends on the object's direction relative to self-motion. Next, we ask whether a subject's belief about whether an object is moving in the world affects their depth judgement. Six subjects were asked to judge the depth of an object relative to the plane of fixation as well as whether the object moves relative to the scene. We find that, on average, subjects show a greater depth bias if they mistake a moving object as "not moving" when object motion information is ambiguous. Finally, we construct three Bayesian inference models with each model implementing a mechanism for depth discrimination. Our model comparison results show that the model which implements subjects' belief about whether an object moves relative to the scene can best explain the perceptual depth biases we observed."--Pages x-xi.
Download or read book Depth Perception Through Motion written by Myron L. Braunstein and published by Academic Press. This book was released on 2014-05-10 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Series in Cognition and Perception: Depth Perception Through Motion focuses on the processes, methodologies, and techniques involved in depth perception through motion, including optic array, rigid motions, illusions, and axis. The book first elaborates on the paradox of depth perception, illusions of motion in depth, and optic array. Discussions focus on rigid motions in three-dimensional space, perspective gradients, projection plane, stereokinetic effect, rotating trapezoid, and the windmill and fan illusions. The text then examines transformations leading to the perception of depth, slant perception, and perceived direction of rotary motion. Topics include shadow and computer projections, direct observation of rotating figures, a model of the perception of rotary motion, dynamic slant and static slant perception, translations along the Z axis, and rotations about the X or Y axis. The publication is intended for researchers and graduate students interested in depth perception in dynamic environments.
Download or read book Foundations of Vision written by Brian A. Wandell and published by Sinauer Associates, Incorporated. This book was released on 1995 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designed for students, scientists and engineers interested in learning about the core ideas of vision science, this volume brings together the broad range of data and theory accumulated in this field.
Download or read book The Perception of Object Motion During Self Motion written by Diederick Christian Niehorster and published by Open Dissertation Press. This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "The Perception of Object Motion During Self-motion" by Diederick Christian, Niehorster, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: When we stand still and do not move our eyes and head, the motion of an object in the world or the absence thereof is directly given by the motion or quiescence of the retinal image. Self-motion through the world however complicates this retinal image. During self-motion, the whole retinal image undergoes coherent global motion, called optic flow. Self-motion therefore causes the retinal motion of objects moving in the world to be confounded by a motion component due to self-motion. How then do we perceive the motion of an object in the world when we ourselves are also moving? Although non-visual information about self-motion, such as provided by efference copies of motor commands and vestibular stimulation, might play a role in this ability, it has recently been shown that the brain possesses a purely visual mechanism that underlies scene-relative object motion perception during self-motion. In the flow parsing hypothesis developed by Rushton and Warren (2005; Warren & Rushton, 2007; 2009b), the brain uses its sensitivity to optic flow to detect and globally remove retinal motion due to self-motion and recover the scene-relative motion of objects. Research into this perceptual ability has so far been of a qualitative nature. In this thesis, I therefore develop a retinal motion nulling paradigm to measure the gain with which the flow parsing mechanism uses the optic flow to remove the self-motion component from an object's retinal motion. I use this paradigm to investigate how accurate scene-relative object motion perception during self-motion can be based on only visual information, whether this flow parsing process depends on a percept of the direction of self-motion and the tuning of flow parsing, i.e., how it is modulated by changes in various stimulus aspects. The results reveal that although adding monocular or binocular depth information to the display to precisely specify the moving object's 3D position in the scene improved the accuracy of flow parsing, the flow parsing gain was never up to the extent required by the scene geometry. Furthermore, the flow parsing gain was lower at higher eccentricities from the focus of expansion in the flow field and was strongly modulated by changes in the motion angle between the self-motion and object motion components in the retinal motion of the moving object, the speeds of these components and the density of the flow field. Lastly, flow parsing was not affected by illusory changes in the perceived direction of self-motion. In conclusion, visual information alone is not sufficient for accurate perception of scene-relative object motion during self-motion. Furthermore, flow parsing takes the 3D position of the moving object in the scene into account and is not a uniform global subtraction process. 8e observed tuning characteristics are different from those of local perceived motion interactions, providing evidence that flow parsing is a separate process from these local motion interactions. Finally, flow parsing does not depend on a prior percept of self-motion direction and instead directly uses the input retinal motion to construct percepts of scene-relative object motion during self-motion. DOI: 10.5353/th_b5177318 Subjects: Motion perception (Vision)
Download or read book Perception Control of Self motion written by Rik Warren and published by Psychology Press. This book was released on 1990 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: First Published in 1990. Routledge is an imprint of Taylor & Francis, an informa company.
Download or read book Neural Basis of Object Motion Perception During Self motion written by Nicole E. Peltier and published by . This book was released on 2020 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The ability to perceive independently moving objects during self-motion is vital for reaching goals and avoiding obstacles. Self-motion generates a structured pattern of retinal motion called optic flow. An independently moving object produces retinal motion that is the vector sum of its world-relative motion and the optic flow created by the observer's self-motion. To interpret the object's world-relative motion, an observer must compensate for their self-motion. The flow-parsing hypothesis posits that the visual system may accomplish this compensation by globally subtracting out the optic flow due to self-motion (Rushton & Warren, 2005; P.A. Warren & Rushton, 2007, 2009a). This subtraction induces a perceptual bias (in retinal coordinates) away from the optic flow vector at the object's location. Despite psychophysical evidence for flow parsing in humans, the neural mechanisms underlying flow parsing remained unknown. This thesis presents the first evidence for a neural correlate to flow parsing in the middle temporal area (MT). First, we tested the flow-parsing hypothesis in an animal model using macaque monkeys. Two monkeys discriminated the direction of a moving object in the presence of optic flow simulating self-motion. Perception of object motion was biased in a manner consistent with flow parsing. Biases generally depended on the direction and magnitude of the optic flow vectors to subtract at the object's location. The addition of vestibular self-motion cues increased flow-parsing biases in a multiplicative manner. This perceptual evidence of flow parsing in monkeys positioned us to investigate its neural mechanisms. Next, we recorded neural activity in area MT while monkeys performed the same flow-parsing discrimination task. The responses of individual MT units to object motion were modulated by optic flow, and this modulation depended on a unit's direction tuning. We used population decoding to demonstrate that MT populations convey information about choice, retinal object motion, and world-relative object motion. Finally, we characterized the effect of optic flow on MT direction tuning curves by modeling each unit's reference frame as a weighted average of retinal and world-centered. The average MT unit modestly shifted its reference frame from retinal toward world-centered. These small shifts suggest that MT plays a role in a more extensive flow-parsing network"--Pages x-xi
Download or read book The Cambridge Handbook of Applied Perception Research written by Robert R. Hoffman and published by Cambridge University Press. This book was released on 2015-01-26 with total page 1468 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cambridge Handbook of Applied Perception Research covers core areas of research in perception with an emphasis on its application to real-world environments. Topics include multisensory processing of information, time perception, sustained attention, and signal detection, as well as pedagogical issues surrounding the training of applied perception researchers. In addition to familiar topics, such as perceptual learning, the Handbook focuses on emerging areas of importance, such as human-robot coordination, haptic interfaces, and issues facing societies in the twenty-first century (such as terrorism and threat detection, medical errors, and the broader implications of automation). Organized into sections representing major areas of theoretical and practical importance for the application of perception psychology to human performance and the design and operation of human-technology interdependence, it also addresses the challenges to basic research, including the problem of quantifying information, defining cognitive resources, and theoretical advances in the nature of attention and perceptual processes.
Download or read book Perceiving Events and Objects written by Gunnar Jansson and published by Psychology Press. This book was released on 2013-06-17 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beginning with his doctoral dissertation in 1950 which introduced the study of event perception and the application of vector analysis to perception, Gunnar Johansson has been a seminal figure in the field of perception. His work on biomechanical motion in the 1970s challenged conventional notions and stimulated great interest among experimental psychologists and students of machine vision. In 1989 Johansson published his latest theoretical synthesis, the optic sphere theory, an innovative conceptualization that goes beyond his earlier proposals. This volume presents -- for the first time -- an extensive precis of the out-of-print classic 1950 monograph prepared by Johansson. It also includes a representative set of Johansson's important publications produced over the ensuing four decades. These papers served as the springboard for a set of original essays by a distinguished group of North American and European scientists. Part critical commentary, part elaboration, and part seeking new directions, the entire collection makes for a singularly rich treatment of the perception of objects and events.
Download or read book Contextual Interactions in Cortical Motion and Surface Perception written by Julia Berzhanskaya and published by . This book was released on 2005 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This dissertation describes neural modeling and psychophysical experiments that clarify how ambiguous visual signals can be disambiguated by contextual interactions. A neural model of the V1-V2-MT-MST areas of the visual cortex is developed to explain how context can influence motion percepts. Psychophysical experiments clarify how context can influence the perception of gloss on a 3D surface and support earlier model predictions about perceptual surface formation. To process object motion in cluttered environments, the brain has to solve multiple problems. One concerns aperture ambiguity. If a featureless line is observed through an aperture in an occluding surface, the perceived direction of motion is perpendicular to the line and may differ from the real motion direction. Integration of motion across apertures helps to determine the true direction of motion. If multiple moving objects overlap, motion segmentation and motion separation in depth help to limit the areas of motion integration. Figure-ground constraints also help to disambiguate the object to which a moving feature belongs. Thus, both form and motion information are combined in the current 3D FORMOTION model to accurately determine object motion. The model simulates effects of visible and invisible occluders on segregation of motion signals within and across depth, and how object shape and nearby objects can influence motion percepts. The psychophysical experiments clarify how percepts of gloss in an image can change as a function distance on the depicted surface rather than of distance in the image plane. Data suggest that the perception of gloss depends on a spatially local filling-in process, or gloss propagation, that is triggered by distinctive highlight features in the context of a 3D surface representation. Space-variant gloss ratings can be explained by generalizing previous models of brightness perception.
Download or read book The Senses A Comprehensive Reference written by and published by Academic Press. This book was released on 2020-09-30 with total page 5215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Senses: A Comprehensive Reference, Second Edition, Seven Volume Set is a comprehensive reference work covering the range of topics that constitute current knowledge of the neural mechanisms underlying the different senses. This important work provides the most up-to-date, cutting-edge, comprehensive reference combining volumes on all major sensory modalities in one set. Offering 264 chapters from a distinguished team of international experts, The Senses lays out current knowledge on the anatomy, physiology, and molecular biology of sensory organs, in a collection of comprehensive chapters spanning 4 volumes. Topics covered include the perception, psychophysics, and higher order processing of sensory information, as well as disorders and new diagnostic and treatment methods. Written for a wide audience, this reference work provides students, scholars, medical doctors, as well as anyone interested in neuroscience, a comprehensive overview of the knowledge accumulated on the function of sense organs, sensory systems, and how the brain processes sensory input. As with the first edition, contributions from leading scholars from around the world will ensure The Senses offers a truly international portrait of sensory physiology. The set is the definitive reference on sensory neuroscience and provides the ultimate entry point into the review and original literature in Sensory Neuroscience enabling students and scientists to delve into the subject and deepen their knowledge. All-inclusive coverage of topics: updated edition offers readers the only current reference available covering neurobiology, physiology, anatomy, and molecular biology of sense organs and the processing of sensory information in the brain Authoritative content: world-leading contributors provide readers with a reputable, dynamic and authoritative account of the topics under discussion Comprehensive-style content: in-depth, complex coverage of topics offers students at upper undergraduate level and above full insight into topics under discussion
Download or read book Perception of Space and Motion written by William Epstein and published by Elsevier. This book was released on 1995-09-15 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past 25 years, the field of space and motion perception has rapidly advanced. Once thought to be distinct perceptual modes, space and motion are now thought to be closely linked. Perception of Space andMotion provides a comprehensive review of perception and vision research literature, including new developments in the use of sound and touch in perceiving space and motion. Other topics include the perception of structure from motion, spatial layout,and information obtained in static and dynamic stimulation.Spatial layoutStructure from motionInformation on static and dynamic stimulation (visual, acoustic, and haptic)
Download or read book The Neural Bases of Multisensory Processes written by Micah M. Murray and published by CRC Press. This book was released on 2011-08-25 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has become accepted in the neuroscience community that perception and performance are quintessentially multisensory by nature. Using the full palette of modern brain imaging and neuroscience methods, The Neural Bases of Multisensory Processes details current understanding in the neural bases for these phenomena as studied across species, stages of development, and clinical statuses. Organized thematically into nine sub-sections, the book is a collection of contributions by leading scientists in the field. Chapters build generally from basic to applied, allowing readers to ascertain how fundamental science informs the clinical and applied sciences. Topics discussed include: Anatomy, essential for understanding the neural substrates of multisensory processing Neurophysiological bases and how multisensory stimuli can dramatically change the encoding processes for sensory information Combinatorial principles and modeling, focusing on efforts to gain a better mechanistic handle on multisensory operations and their network dynamics Development and plasticity Clinical manifestations and how perception and action are affected by altered sensory experience Attention and spatial representations The last sections of the book focus on naturalistic multisensory processes in three separate contexts: motion signals, multisensory contributions to the perception and generation of communication signals, and how the perception of flavor is generated. The text provides a solid introduction for newcomers and a strong overview of the current state of the field for experts.
Download or read book Functional Movement Development Across the Life Span written by Donna Joy Cech and published by Elsevier Health Sciences. This book was released on 2011-09-06 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a solid foundation in the normal development of functional movement, Functional Movement Development Across the Life Span, 3rd Edition helps you recognize and understand movement disorders and effectively manage patients with abnormal motor function. It begins with coverage of basic theory, motor development and motor control, and evaluation of function, then discusses the body systems contributing to functional movement, and defines functional movement outcomes in terms of age, vital functions, posture and balance, locomotion, prehension, and health and illness. This edition includes more clinical examples and applications, and updates data relating to typical performance on standardized tests of balance. Written by physical therapy experts Donna J. Cech and Suzanne "Tink" Martin, this book provides evidence-based information and tools you need to understand functional movement and manage patients' functional skills throughout the life span. - Over 200 illustrations, tables, and special features clarify developmental concepts, address clinical implications, and summarize key points relating to clinical practice. - A focus on evidence-based information covers development changes across the life span and how they impact function. - A logical, easy-to-read format includes 15 chapters organized into three units covering basics, body systems, and age-related functional outcomes respectively. - Expanded integration of ICF (International Classification of Function) aligns learning and critical thinking with current health care models. - Additional clinical examples help you apply developmental information to clinical practice. - Expanded content on assessment of function now includes discussion of participation level standardized assessments and assessments of quality-of-life scales. - More concise information on the normal anatomy and physiology of each body system allows a sharper focus on development changes across the lifespan and how they impact function.
Download or read book Perception with an Eye for Motion written by James E. Cutting and published by MIT Press (MA). This book was released on 1986-01 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perception with an Eye for Motionanalyzes the availability and use of visual information from moving objects and by moving observers to conclude that information in our visual environment is sufficiently rich so that perception can occur largely without the help of cognition. The book is unique in several respects. It is interdisciplinary in scope, combining philosophy, history, perceptual science, and research in a sound balance; the problems that philosophers and computer scientists are dealing with are taken up in a way that will appeal to psychologists. It is the first book to treat invariance in perception in a rigorous manner, and it solves the problem of direction finding in optic flow (the motions of objects generated by our own movement through space) by discerning what information is useful and can be relied upon. The first five chapters take up information for vision, delving into philosophical and historical issues, particularly the trustworthiness of perception, and the relation of space and projections of objects as'discussed in art and science. These chapters also cover optics, illusions, picture perception, and more particularly invariance as a term from mathematics applied to perception. Eight chapters present the author's own research, published here for the first time. These include experiments and results concerning the perception of a moving planar surface and the perception of one's direction of movement through an environment. The book concludes by discussing two centuries-old classes of perceptual theory - direct and indirect perception - and a new theory class which the author calls "directed perception." James E. Cutting is Professor of Psychology, Cornell University. A Bradford Book.
Download or read book Spatial Biases in Perception and Cognition written by Timothy L. Hubbard and published by Cambridge University Press. This book was released on 2018-08-23 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous spatial biases influence navigation, interactions, and preferences in our environment. This volume considers their influences on perception and memory.
Download or read book Elements of Psychophysics written by Gustav Theodor Fechner and published by . This book was released on 1966 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multisensory Perception written by K. Sathian and published by Academic Press. This book was released on 2019-09-15 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multisensory Perception: From Laboratory to Clinic surveys the current state of knowledge on multisensory processes, synthesizing information from diverse streams of research and defining hypotheses and questions to direct future work. Reflecting the nature of the field, the book is interdisciplinary, comprising the findings and views of writers with diverse backgrounds and varied methods, including psychophysical, neuroanatomical, neurophysiological and neuroimaging approaches. Sections cover basic principles, specific interactions between the senses, the topic of crossmodal correspondences between particular sensory attributes, the related topic of synesthesia, and the clinic. - Offers a comprehensive, up-to-date overview of the current state of knowledge on multisensory processes - Coverage includes basic principles, specific interactions between the senses, crossmodal correspondences and the clinical aspects of multisensory processes - Includes psychophysical, neuroanatomical, neurophysiological and neuroimaging approaches
