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 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 Motion Perception for Visual Navigation written by Saqib Ishaq Khan and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 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 Neural Basis of Visual Motion Perception written by Yunmin Wu and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Perception of Self Motion written by Alessandro Nesti and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Everyday life requires humans to move through the environment, while completing crucial tasks such as retrieving nourishment, avoiding perils or controlling motor vehicles. Success in these tasks largely relies in a correct perception of self-motion, i.e. the continuous estimation of one's body position and its derivatives with respect to the world. The processes underlying self-motion perception have fascinated neuroscientists for more than a century and large bodies of neural, behavioural and physiological studies have been conducted to discover how the central nervous system integrates available sensory information to create an internal representation of the physical motion. The goal of this PhD thesis is to extend current knowledge on self-motion perception by focusing on conditions that closely resemble typical aspects of everyday life. In the works conducted within this thesis, I isolate different components typical of everyday life motion and employ psychophysical methodologies to systematically investigate their effect on human self-motion sensitivity. Particular attention is dedicated to the human ability to discriminate between motions of different intensity. How this is achieved has been a fundamental question in the study of perception since the seminal works of Weber and Fechner. When tested over wide ranges of rotations and translations, participants' sensitivity (i.e. their ability to detect motion changes) is found to decrease with increasing motion intensities, revealing a nonlinearity in the perception of self-motion that is not present at the level of ocular reflexes or in neural responses of sensory afferents. The relationship between the stimulus intensity and the smallest intensity change perceivable by the participants can be mathematically described by a power law, regardless on the sensory modality investigated (visual or inertial) and on whether visual and inertial cues were presented alone or congruently combined, such as during natural movements. Individual perceptual law parameters were fit based on experimental data for upward and downward translations and yaw rotations based on visual-only, inertial-only and combined visual-inertial motion cues. Besides wide ranges of motion intensities, everyday life scenarios also provide complex motion patterns involving combinations of rotational and translational motion, visual and inertial sensory cues and physical and mental workload. The question of how different combinations of these factors affect motion sensitivity was experimentally addressed within the framework of driving simulation and revealed that sensitivity might strongly decrease in more realistic conditions, where participants do not only focus on perceiving a 'simple' motion stimulus (e.g. a sinusoidal profile at a specific frequency) but are, instead, actively engaged in a dynamic driving simulation. Applied benefits of the present thesis include advances in the field of vehicle motion simulation, where knowledge on human self-motion perception supports the development of state-of-the-art algorithms to control simulator motion. This allows for reproducing, within a safe and controlled environment, driving or flying experiences that are perceptually realistic to the user. Furthermore, the present work will guide future research into the neural basis of perception and action.

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 Visual motion and self motion processing in the human brain MPI Series in Biological Cybernetics Bd 31 written by Elvira Fischer and published by Logos Verlag Berlin GmbH. This book was released on 2011 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the successful recognition of objective, `real' motion based on visual cues it is necessary to take self-induced motion signals into account, such as those induced by eye-movements. During a series of fMRI studies we measured responses of visual and parietal regions to motion cues derived from (a) retinal motion, (b) eyemovements (visual pursuit) and (c) objective, (real) motion. We show that the recently described cingulate sulcus visual area (CSv) is not, as implied before, primarily driven by 3D self-motion cues but favoured 2D translational coherent motion over 3D expanding flow fields. Further, we found that V3A is capable of integrating retinal motion with eye-movements, thus allowing V3A to respond to object motion independent of retinal motion. This allowed us to define a new functional localizer for area V3A. Finally, we showed that activity in the foveal representation of the early visual cortex is driven by a combination of retinal input and by error signals as hypothesized by of Rao and Ballard (1999) for predictive coding. Taken together, this work provides evidence that regions V3A and CSv are key regions concerning visual self-motion processing and that early visual regions might be modulated by feedback from higher motion processing regions.

Download or read book Visual Control of Locomotion written by Brett R. Fajen and published by Cambridge University Press. This book was released on 2021-04-22 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Element examines visual perception in the context of activities that involve moving about in complex, dynamic environments. A central theme is that the ability of humans and other animals to perceive their surroundings based on vision is profoundly shaped by the need to adaptively regulate locomotion to variations in the environment. As such, important new insights into what and how we perceive can be gleaned by investigating the connection between vision and the control of locomotion. I present an integrated summary of decades of research on the perception of self-motion and object motion based on optic flow, the perception of spatial layout and affordances, and the control strategies for guiding locomotion based on visual information. I also explore important theoretical issues and debates, including the question of whether visual control relies on internal models.

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

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 The brain meets the body Neural basis of cognitive contribution in movement for healthy and neurological populations written by Daniela De Bartolo and published by Frontiers Media SA. This book was released on 2023-11-06 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamic Neural Field Theory for Motion Perception written by Martin A. Giese and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic Neural Field Theory for Motion Perception provides a new theoretical framework that permits a systematic analysis of the dynamic properties of motion perception. This framework uses dynamic neural fields as a key mathematical concept. The author demonstrates how neural fields can be applied for the analysis of perceptual phenomena and its underlying neural processes. Also, similar principles form a basis for the design of computer vision systems as well as the design of artificially behaving systems. The book discusses in detail the application of this theoretical approach to motion perception and will be of great interest to researchers in vision science, psychophysics, and biological visual systems.

Download or read book Neural Basis of Motion Perception written by V. S. Ramachandran and published by . This book was released on 1993 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research is concerned with visual surface representation and the manner in which visual image segmentation influences certain early visual processes such as stereopsis, motion correspondence, structure from motion, shape from shading, and the "aperture problem." A number of new visual effects in the laboratory (e.g. "motion capture", stereoscopic capture, etc.) have given novel insights in to the mechanisms underlying human motion perception and stereopsis.

Download or read book Perception and Control of Self motion written by Rik Warren and published by Psychology Press. This book was released on 2014-01-14 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents studies of self-motion by an international group of basic and applied researchers including biologists, psychologists, comparative physiologists, kinesiologists, aerospace and control engineers, physicians, and physicists. Academia is well represented and accounts for most of the applied research offered. Basic theoretical research is further represented by private research companies and also by government laboratories on both sides of the Atlantic. Researchers and students of biology, psychology, physiology, kinesiology, engineering, and physics who have an interest in self-motion -- whether it be underwater, in space, or on solid ground -- will find this volume of interest. This book presents studies of self-motion by an international group of basic and applied researchers including biologists, psychologists, comparative physiologists, kinesiologists, aerospace and control engineers, physicians, and physicists. Academia is well represented and accounts for most of the applied research offered. Basic theoretical research is further represented by private research companies and also by government laboratories on both sides of the Atlantic. Researchers and students of biology, psychology, physiology, kinesiology, engineering, and physics who have an interest in self-motion -- whether it be underwater, in space, or on solid ground -- will find this volume of interest.