Download or read book Neural Mechanisms Underlying Core Visual Perception of Objects written by and published by . This book was released on 2015 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visual perception of objects is a computationally challenging problem and fundamental to human well-being. Extensive previous research has revealed that the inferior temporal cortex (IT), a high-level visual area, is involved in various aspects of visual perception. Yet, little is known about: how IT neural responses to objects support human perception of the objects; and how IT responses are produced from retinal images of objects. The goal of this research is to tackle these two related questions and find out explicit, quantitative mechanisms that describe human core visual perception of objects, a remarkable ability achieved with brief (

Download or read book Multisensory Object Perception in the Primate Brain written by Marcus Johannes Naumer and published by Springer Science & Business Media. This book was released on 2010-07-03 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: It should come as no surprise to those interested in sensory processes that its research history is among the longest and richest of the many systematic efforts to understand how our bodies function. The continuing obsession with sensory systems is as much a re?ection of the fundamental need to understand how we experience the physical world as it is to understand how we become who we are based on those very experiences. The senses function as both portal and teacher, and their individual and collective properties have fascinated scientists and philosophers for millennia. In this context, the attention directed toward specifying their properties on a sense-by-sense basis that dominated sensory research in the 20th century seems a prelude to our current preoccupation with how they function in concert. Nevertheless, it was the concentrated effort on the operational principles of in- vidual senses that provided the depth of understanding necessary to inform current efforts to reveal how they act cooperatively. We know that the information provided by any individual sensory modality is not always veridical, but is subject to a myriad of modality-speci?c distortions. Thus, the brain’s ability to compare across the senses and to integrate the information they provide is not only a way to examine the accuracy of any individual sensory channel but also a way to enhance the collective information they make available to the brain.

Download or read book The Neural Mechanisms Underlying the Perception of Visual Illusions written by Hang Zeng and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Visual Object Processing written by Glyn W. Humphreys and published by Routledge. This book was released on 2017-03-27 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in 1987, this book, attempted to bring together work by researchers concerned with the functional and neurological mechanisms underlying visual object processing, and the ways in which such mechanisms can be neurologically impaired. The editors termed it a ‘Cognitive Neuropsychological’ approach, because they believed it tried to relate evidence from neurological impairments of visual object processing to models of normal performance in a new and important way. Two broad aims are apparent. One is to test models of normal performance by evaluating how well the models account for the patterns of impairment and preservation of abilities that can occur following brain damage. The other is to use models of normal performance to further their understanding of acquired disorders of visual object processing. These aims distinguish the approach from neuropsychological work whose primary aim is to relate acquired deficits to the sites of damage, and from work in the field of cognitive psychology which attempts only to develop models of normal performance.

Download or read book What can simple brains teach us about how vision works written by Davide Zoccolan and published by Frontiers Media SA. This book was released on 2015-11-18 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vision is the process of extracting behaviorally-relevant information from patterns of light that fall on retina as the eyes sample the outside world. Traditionally, nonhuman primates (macaque monkeys, in particular) have been viewed by many as the animal model-of-choice for investigating the neuronal substrates of visual processing, not only because their visual systems closely mirror our own, but also because it is often assumed that “simpler” brains lack advanced visual processing machinery. However, this narrow view of visual neuroscience ignores the fact that vision is widely distributed throughout the animal kingdom, enabling a wide repertoire of complex behaviors in species from insects to birds, fish, and mammals. Recent years have seen a resurgence of interest in alternative animal models for vision research, especially rodents. This resurgence is partly due to the availability of increasingly powerful experimental approaches (e.g., optogenetics and two-photon imaging) that are challenging to apply to their full potential in primates. Meanwhile, even more phylogenetically distant species such as birds, fish, and insects have long been workhorse animal models for gaining insight into the core computations underlying visual processing. In many cases, these animal models are valuable precisely because their visual systems are simpler than the primate visual system. Simpler systems are often easier to understand, and studying a diversity of neuronal systems that achieve similar functions can focus attention on those computational principles that are universal and essential. This Research Topic provides a survey of the state of the art in the use of animal models of visual functions that are alternative to macaques. It includes original research, methods articles, reviews, and opinions that exploit a variety of animal models (including rodents, birds, fishes and insects, as well as small New World monkey, the marmoset) to investigate visual function. The experimental approaches covered by these studies range from psychophysics and electrophysiology to histology and genetics, testifying to the richness and depth of visual neuroscience in non-macaque species.

Download or read book Neural Mechanisms of Position Perception written by Jessica Wright and published by . This book was released on 2014 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visual perception is a reconstruction of the physical visual aspects of the world and subject to various biases, assumptions and noise. One aspect of visual perception is visuospatial localization. Although visual localization is typically accurate, there are various situations where healthy human subjects mislocalize objects, as well as, neurological disorders that alter visual localization behavior. These situations result in differences between the perceived and actual position of an object. These perceptual errors are useful to explore the limitations of visuospatial object localization and provide information on the underlying neural mechanisms of position perception. In particular, the following studies investigated how the brain integrates visual information across a spatially extended stimulus and ultimately results in a final percept of position. This project utilized behavioral and fMRI studies combined with transcranial direct current stimulation (tDCS) in healthy human subjects. These methods allowed us to quantify behavioral errors in localization and examine changes in the BOLD signal (as an indirect measure of changes in neural activity) in potential neural correlates of position perception. In Aim 1 we show that factors such as retinal eccentricity and attentional cues bias localization behavior via alterations of the contribution of specific object components in the integration process. Aim 2 shows that tDCS over posterior parietal cortex (PPC) yields mislocalizations that are consistent with predictions from the interhemispheric competition theory (ICT) of attention. This supports the causal role of PPC in visual spatial localization. Aim 3 extends the results from Aim 2 to show that the BOLD signal changes in PPC predict localization behavior. In addition to novel insights related to position perception, these experiments provide insight into the effects of tDCS on behavior and the interaction of tDCS with the BOLD signal. This work begins to answer how different factors influence position perception and the role of different cortical regions in position perception. This research also has implications for rehabilitation programs for patients with various visual neurological disorders that alter spatial perception.

Download or read book Neural Mechanisms of Visual Perception written by Retina Research Foundation (U.S.). Symposium and published by . This book was released on 1989 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neural Mechanisms of Visual Perception written by Dominic Man-Kit Lam and published by MIT Press (MA). This book was released on 1991-04-24 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume Two April 14-15, 1989, The Woodlands, Texas

Download or read book Perceiving and Acting in the Real World From Neural Activity to Behavior written by Simona Monaco and published by Frontiers Media SA. This book was released on 2016-12-07 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: One remarkable ability of the human brain is to process large amounts of information about our surroundings to allow us to interact effectively with them. In everyday life, the most common way to interact with objects is by reaching, grasping, lifting and manipulating them. Although these may sound like simple tasks, the perceptual properties of the target object, such as its location, size, shape, and orientation all need to be processed in order to set the movement parameters that allow an accurate reach-to-grasp-to lift movement. Several brain areas work in concert to process this outstanding amount of visual information and drive the execution of a motor plan in just a few hundred milliseconds. How are these processes orchestrated? In developing this type of comprehensive knowledge about the interactions between objects perception and goal-directed actions, we have a window into the mechanisms underlying the functioning of the visuo-motor system. With this research topic we aim to further understand the neural mechanisms that mediate our interactions with the world. Therefore, we particularly encourage submission of papers that attempt to relate such findings to real-world situations by investigating behavioural and neural correlates of information processing related to eye-hand coordination and visually-guided actions, including reaching, grasping, and lifting movements. This topic welcomes submissions of original research using any relevant techniques and methods, from behavioural kinematics/kinetics, to neuroimaging and transcranial magnetic stimulation (TMS), as well as neuropsychological studies.

Download or read book Neural Mechanisms of Context driven Conscious Visual Perception written by P. C. Klink and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neural Mechanisms of Visual Perception Using Address Event Representation written by Luma Issa Abdul-Kreem Al-Helli and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Neuroscience of Expertise written by Merim Bilalić and published by Cambridge University Press. This book was released on 2017-02-16 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Neuroscience of Expertise examines the ways in which the brain accommodates the incredible feats of experts. It builds on a tradition of cognitive research to explain how the processes of perception, attention, and memory come together to enable experts' outstanding performance. The text explains how the brain adapts to enable the complex cognitive machinery behind expertise, and provides a unifying framework to illuminate the seemingly unconnected performance of experts in different domains. Whether it is a radiologist who must spot a pathology in a split second, a chess grandmaster who finds the right path in a jungle of possible continuations, or a tennis professional who reacts impossibly quickly to return a serve, The Neuroscience of Expertise offers insight into the universal cognitive and neural mechanisms behind these achievements.

Download or read book On Seeing Forms written by William R. Uttal and published by Psychology Press. This book was released on 2014-06-27 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in 1988, this is the final volume in the set. The original intent of the tetralogy was to review neural explanations of high level perceptual and cognitive processes. However, at this point, it became clear that there were few neural explanations of perceptual topics – a situation that still persists today. This book, therefore, used a different framework examining the role of detection, discrimination, and recognition at the behavioral level.

Download or read book Discovering the Brain written by National Academy of Sciences and published by National Academies Press. This book was released on 1992-01-01 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain ... There is no other part of the human anatomy that is so intriguing. How does it develop and function and why does it sometimes, tragically, degenerate? The answers are complex. In Discovering the Brain, science writer Sandra Ackerman cuts through the complexity to bring this vital topic to the public. The 1990s were declared the "Decade of the Brain" by former President Bush, and the neuroscience community responded with a host of new investigations and conferences. Discovering the Brain is based on the Institute of Medicine conference, Decade of the Brain: Frontiers in Neuroscience and Brain Research. Discovering the Brain is a "field guide" to the brainâ€"an easy-to-read discussion of the brain's physical structure and where functions such as language and music appreciation lie. Ackerman examines: How electrical and chemical signals are conveyed in the brain. The mechanisms by which we see, hear, think, and pay attentionâ€"and how a "gut feeling" actually originates in the brain. Learning and memory retention, including parallels to computer memory and what they might tell us about our own mental capacity. Development of the brain throughout the life span, with a look at the aging brain. Ackerman provides an enlightening chapter on the connection between the brain's physical condition and various mental disorders and notes what progress can realistically be made toward the prevention and treatment of stroke and other ailments. Finally, she explores the potential for major advances during the "Decade of the Brain," with a look at medical imaging techniquesâ€"what various technologies can and cannot tell usâ€"and how the public and private sectors can contribute to continued advances in neuroscience. This highly readable volume will provide the public and policymakersâ€"and many scientists as wellâ€"with a helpful guide to understanding the many discoveries that are sure to be announced throughout the "Decade of the Brain."

Download or read book Feature Specific Mechanisms in the Human Brain written by Christian Kaul and published by LAP Lambert Academic Publishing. This book was released on 2010-09 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: What are the current limits of our knowledge of brain activity underlying vision and how can it be furthered? In this book, I explore this basic question with hands-on experimental studies. I focus on those aspects of visual input that can be described as basic features of visual perception. However, understanding how humans visually perceive the external world is closely related with the study of attention. Attention, that is, the selection of some aspects of the environment over others, is one of the most intensively studied areas in experimental psychology, yet its neural mechanisms remain largely elusive. This thesis focuses on three distinct studies at the border of feature-specific visual perception and feature-specific visual attention. I explore the influence of heightened attentional demand (load) in a central task, investigate the influence of feature- based attention on neural processing of early visual cortices and examine how and where in the brain gender discrimination might receive neural processing. I discuss all findings in the light of the current research, for their scientific significance and for future research opportunities.

Download or read book The Two Sides of Perception written by Richard B. Ivry and published by MIT Press. This book was released on 1998 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anatomically, the central nervous system looks remarkably symmetrical--from the relatively simple structures of the spinal cord to the extensively convoluted folds of the cerebral hemispheres. At the functional level, however, there are striking differences between the left and right hemispheres. Although popular writings attribute language abilities to the left hemisphere and spatial abilities to the right, differences in hemispheric function appear to be more subtle. According to Ivry and Robertson, asymmetries over a wide range of perceptual tasks reflect a difference in strength rather than kind, with both hemispheres contributing to the performance of complex tasks, whether linguistic or spatial. After an historical introduction, the authors offer a cognitive neuroscience perspective on hemispheric specialization in perception. They propose that the two hemispheres differ in how they filter task-relevant sensory information. Building on the idea that the hemispheres construct asymmetric representations, the hypothesis provides a novel account of many laterality effects. A notable feature of the authors' work is their attempt to incorporate hemispheric specialization in vision, audition, music, and language within a common framework. In support of their theory, they review studies involving both healthy and neurologically impaired individuals. They also provide a series of simulations to demonstrate the underlying computational principles of their theory. Their work thus describes both the cognitive and neurological architecture of hemispheric asymmetries in perception.

Download or read book Neural Mechanisms of Visual Segmentation Using Motion and Depth Cues in Cortical Area MT written by Venkta Lakshmi Anjani Chakrala and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our dynamic world requires us to discern objects in complex environments to effectively interact with our surroundings. Our visual system has the remarkable ability to seamlessly segment objects from each other, unmatched by current machine vision systems, that enables us to understand visual scenes and guides actions. In natural vision, visual motion combined with other features like depth and cognitive abilities like attention is important to segment objects. Visual motion processing is widely studied at both perceptual and physiological levels. However, the neural mechanisms underlying the segmentation of multiple objects aided by motion combined with other features like depth and spatial location are not fully understood. The goal of this dissertation is to elucidate the neural mechanisms underlying the segmentation of multiple objects using motion direction, speed, depth (binocular disparity), and spatial location. Toward this, in chapter 2, I determined the neural representation of multiple objects, that differed in depth and motion direction and investigated the effect of selective attention on this representation. We designed a novel motion discrimination task, in which macaque monkeys selectively attended to one of two moving surfaces separated in depth. The task was paired with electrophysiological recordings from the middle temporal area (MT), known for its selectivity to visual motion and binocular disparity. Our results suggest that to represent multiple surfaces with different depths and motion direction, MT neurons leverage their preference to the binocular disparity of the constituent surfaces, so that the information about the two motion directions is distributed over neuronal subgroups defined by their disparity preferences (near and far-preferred neurons). Selective attention to one disparity enhanced the representation of the attended surface and its motion direction. In chapter 3, I investigated how MT neurons encoded two spatially separated stimuli moving at different speeds. Akin to chapter 2, we found that the MT neurons' spatial and speed preferences to single motion were preserved in their responses to two spatially separated speeds, which might help in their segmentation. Together, our results elucidate prevailing neural strategies of encoding multiple visual stimuli, and how the visual system exploits spatial cues either two-dimensional or three-dimensional, together with motion cues to segment multiple objects.