Perceptual Processes Underlying Depth Judgements of Moving Objects During Self-motion PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Perceptual Processes Underlying Depth Judgements of Moving Objects During Self-motion PDF full book. Access full book title Perceptual Processes Underlying Depth Judgements of Moving Objects During Self-motion by Ranran L.. French. Download full books in PDF and EPUB format.
Author: Ranran L.. French
Publisher:
ISBN:
Category : Depth perception
Languages : en
Pages : 0
Get Book Here
Book Description
"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.
Author: Ranran L.. French
Publisher:
ISBN:
Category : Depth perception
Languages : en
Pages : 0
Get Book Here
Book Description
"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.
Author: Myron L. Braunstein
Publisher: Academic Press
ISBN: 1483276570
Category : Psychology
Languages : en
Pages : 215
Get Book Here
Book Description
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.
Author: Diederick Christian Niehorster
Publisher: Open Dissertation Press
ISBN: 9781361334515
Category :
Languages : en
Pages :
Get Book Here
Book Description
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)
Author: Brian A. Wandell
Publisher: Sinauer Associates, Incorporated
ISBN:
Category : Medical
Languages : en
Pages : 508
Get Book Here
Book Description
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.
Author: Nicole E. Peltier
Publisher:
ISBN:
Category : Motion perception (Vision)
Languages : en
Pages : 242
Get Book Here
Book Description
"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
Author: Robert R. Hoffman
Publisher: Cambridge University Press
ISBN: 1139993534
Category : Psychology
Languages : en
Pages : 1468
Get Book Here
Book Description
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.
Author: Paul A. Kolers
Publisher: Elsevier
ISBN: 1483186946
Category : Psychology
Languages : en
Pages : 235
Get Book Here
Book Description
International Series of Monographs in Experimental Psychology, Volume 16: Aspects of Motion Perception details the fundamental concepts of the visual system perception of motion. The text first details the various findings about illusory and veridical motions along with the theories conceptualized from those findings. Next, the selection covers the research that studies the reliability and validity of the theories about motion perception. The book also discusses the importance of two-component model of motion perception. The last chapter covers the characteristics of the status of perceptual experiences. The book will be of great use to behavioral scientists and biologists. Ophthalmologists will also benefit from the text.
Author:
Publisher: Academic Press
ISBN: 0128054093
Category : Medical
Languages : en
Pages : 5215
Get Book Here
Book Description
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
Author: Alex Holcombe
Publisher: Cambridge University Press
ISBN: 1009007564
Category : Psychology
Languages : en
Pages : 150
Get Book Here
Book Description
Our minds are severely limited in how much information they can extensively process, in spite of being massively parallel at the visual end. When people attempt to track moving objects, only a limited number can be tracked, which varies with display parameters. Associated experiments indicate that spatial selection and updating has higher capacity than selection and updating of features such as color and shape, and is mediated by processes specific to each cerebral hemisphere, such that each hemifield has its own spatial tracking limit. These spatial selection processes act as a bottleneck that gate subsequent processing. To improve our understanding of this bottleneck, future work should strive to avoid contamination of tracking tasks by high-level cognition. While we are far from fully understanding how attention keeps up with multiple moving objects, what we already know illuminates the architecture of visual processing and offers promising directions for new discoveries.
Author: Harriet G. Williams
Publisher:
ISBN:
Category : Motion perception (Vision)
Languages : en
Pages : 492
Get Book Here
Book Description
