Download or read book Cross Species Mechanisms of Orientation Tuning in the Primary Visual Cortex written by Luis Jimenez and published by . This book was released on 2021 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simple cells in the primary visual cortex of all mammals are renown for having an 'orientation preference', meaning that they respond to a specific orientation of an elongated stimulus that lands on their spatial receptive field. Moreover, these cells respond to increments and decrements in luminance in slightly separate regions of their receptive fields, and the angle formed by the centers of these regions can predict their preferred orientation. Despite decades of research into the topic, the mechanism that gives rise to tuned simple cells and their receptive field structure remains an open question. Many models struggle to explain why the properties of simple cells are similar across mammals despite substantial inter-species differences in how simple cells are spatially organized across the cortex. For instance, in the primary visual cortex of cats and primates, vertical columns of cells have similar orientation preferences, and the preferences of these columns rotates smoothly, in a quasiperiodic fashion, as one moves horizontally across the cortex. In contrast, simple cells in mouse primary visual cortex with different tuning preferences are scattered randomly throughout the cortical tissue. Here I assess a mechanistic model of tuning asserting that a single mechanism can generate tuned cells that are either mapped out in an orderly manner across the cortex or arranged in a salt and pepper fashion. The two projects carried out in this thesis test a specific prediction made by the model and compare it to physiological data in mouse primary visual cortex and the thalamic afferents that innervate the cortex. Overall, the results corroborate the model and lend support to the notion that a universal, cross-species mechanism may be used to encode the orientation of a visual stimulus.
Download or read book Inhibitory Mechanisms in the Primary Visual Cortex written by Gary Allan Walker and published by . This book was released on 1998 with total page 524 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 Vision written by Colin Blakemore and published by Cambridge University Press. This book was released on 1993-05-13 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professor Colin Blakemore presents a fascinating insight to all the major topics in visual science research.
Download or read book Vision written by David Marr and published by MIT Press. This book was released on 2010-07-09 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Available again, an influential book that offers a framework for understanding visual perception and considers fundamental questions about the brain and its functions. David Marr's posthumously published Vision (1982) influenced a generation of brain and cognitive scientists, inspiring many to enter the field. In Vision, Marr describes a general framework for understanding visual perception and touches on broader questions about how the brain and its functions can be studied and understood. Researchers from a range of brain and cognitive sciences have long valued Marr's creativity, intellectual power, and ability to integrate insights and data from neuroscience, psychology, and computation. This MIT Press edition makes Marr's influential work available to a new generation of students and scientists. In Marr's framework, the process of vision constructs a set of representations, starting from a description of the input image and culminating with a description of three-dimensional objects in the surrounding environment. A central theme, and one that has had far-reaching influence in both neuroscience and cognitive science, is the notion of different levels of analysis—in Marr's framework, the computational level, the algorithmic level, and the hardware implementation level. Now, thirty years later, the main problems that occupied Marr remain fundamental open problems in the study of perception. Vision provides inspiration for the continuing efforts to integrate knowledge from cognition and computation to understand vision and the brain.
Download or read book Orientation Tuning in Primary Visual Cortex written by Andrew Teich and published by . This book was released on 2005 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contrast invariant Orientation Tuning and Efficient Selection in Human Visual Cortex written by Min Young Lee and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The visual system is a complex network of structures that work together to process and make sense of visual information derived from the surrounding environment. This dissertation explores the challenges faced by the visual system, both externally and internally, in achieving its goal of providing a coherent perception of the visual world. Chapter 2 focuses on contrast-invariant orientation tuning, a remarkable ability of the visual system to maintain stable perception regardless of changes in stimulus contrasts. While extensively studied in non-human primates, the existence of contrast-invariant orientation tuning in human visual cortex has been uncertain. I present evidence that orientation tuning in human visual cortex remains invariant to changes in stimulus contrast. Chapter 3 investigates the neural mechanism of selective attention and its impact on contrast-discrimination behavior. By employing different task designs with varying numbers of targets, the association between the number of targets and different attention mechanisms is examined. It is demonstrated that the efficient selection mechanism is utilized when multiple targets are present, while both the efficient selection and response gain mechanisms are associated with fewer targets. Also, the efficient selection model proves to be effective in explaining the behavior in attention tasks. In investigating these mechanisms, I utilize the steady-state visual evoked potential (SSVEP) frequency tagging technique involving multiple input stimuli, which is an effective tool for studying both sensory and cognitive processes. This dissertation contributes to our understanding of how the human visual system adapts to external changes and internal demands, shedding light on the mechanisms of contrast-invariant orientation tuning and selective attention.
Download or read book Inhibitory Synaptic Plasticity written by Melanie A. Woodin and published by Springer Science & Business Media. This book was released on 2010-11-02 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume will explore the most recent findings on cellular mechanisms of inhibitory plasticity and its functional role in shaping neuronal circuits, their rewiring in response to experience, drug addiction and in neuropathology. Inhibitory Synaptic Plasticity will be of particular interest to neuroscientists and neurophysiologists.
Download or read book Models of the Visual Cortex written by David Rose and published by John Wiley & Sons. This book was released on 1985 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and stimulating study which presents the views of 71 leading theorists on the underlying mechanisms and functions of the primary visual cortex.
Download or read book Micro Meso and Macro Connectomics of the Brain written by Henry Kennedy and published by Springer. This book was released on 2016-03-10 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has brought together leading investigators who work in the new arena of brain connectomics. This includes ‘macro-connectome’ efforts to comprehensively chart long-distance pathways and functional networks; ‘micro-connectome’ efforts to identify every neuron, axon, dendrite, synapse, and glial process within restricted brain regions; and ‘meso-connectome’ efforts to systematically map both local and long-distance connections using anatomical tracers. This book highlights cutting-edge methods that can accelerate progress in elucidating static ‘hard-wired’ circuits of the brain as well as dynamic interactions that are vital for brain function. The power of connectomic approaches in characterizing abnormal circuits in the many brain disorders that afflict humankind is considered. Experts in computational neuroscience and network theory provide perspectives needed for synthesizing across different scales in space and time. Altogether, this book provides an integrated view of the challenges and opportunities in deciphering brain circuits in health and disease.
Download or read book The New Visual Neurosciences written by John S. Werner and published by MIT Press. This book was released on 2013-10-25 with total page 1693 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of contemporary research in the vision sciences, reflecting the rapid advances of recent years. Visual science is the model system for neuroscience, its findings relevant to all other areas. This essential reference to contemporary visual neuroscience covers the extraordinary range of the field today, from molecules and cell assemblies to systems and therapies. It provides a state-of-the art companion to the earlier book The Visual Neurosciences (MIT Press, 2003). This volume covers the dramatic advances made in the last decade, offering new topics, new authors, and new chapters. The New Visual Neurosciences assembles groundbreaking research, written by international authorities. Many of the 112 chapters treat seminal topics not included in the earlier book. These new topics include retinal feature detection; cortical connectomics; new approaches to mid-level vision and spatiotemporal perception; the latest understanding of how multimodal integration contributes to visual perception; new theoretical work on the role of neural oscillations in information processing; and new molecular and genetic techniques for understanding visual system development. An entirely new section covers invertebrate vision, reflecting the importance of this research in understanding fundamental principles of visual processing. Another new section treats translational visual neuroscience, covering recent progress in novel treatment modalities for optic nerve disorders, macular degeneration, and retinal cell replacement. The New Visual Neurosciences is an indispensable reference for students, teachers, researchers, clinicians, and anyone interested in contemporary neuroscience. Associate Editors Marie Burns, Joy Geng, Mark Goldman, James Handa, Andrew Ishida, George R. Mangun, Kimberley McAllister, Bruno Olshausen, Gregg Recanzone, Mandyam Srinivasan, W.Martin Usrey, Michael Webster, David Whitney Sections Retinal Mechanisms and Processes Organization of Visual Pathways Subcortical Processing Processing in Primary Visual Cortex Brightness and Color Pattern, Surface, and Shape Objects and Scenes Time, Motion, and Depth Eye Movements Cortical Mechanisms of Attention, Cognition, and Multimodal Integration Invertebrate Vision Theoretical Perspectives Molecular and Developmental Processes Translational Visual Neuroscience
Download or read book Recurrent Network Dynamics Modulate Orientation Tuning in Primary Visual Cortex written by Maria del Mar Quiroga and published by . This book was released on 2015 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Orientation Mapping Based on Optical Recordings of the Feline Visual Cortex written by Danil M. Gorinevski and published by . This book was released on 1998 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pattern Recognition Mechanisms written by Carlos Chagas and published by Springer. This book was released on 2014-08-23 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Computing Neuron written by Richard Durbin and published by Addison Wesley Publishing Company. This book was released on 1989 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of recent developments in biological neuroscience and artificial neural networks. Based on a selection of work presented to a meeting on The Neuron as a Computational Unit held in Cambridge in 1988, it brings together the work of leading scientists in neurophysiology and computational neuroscience.
Download or read book Brain Inspired Computing written by Katrin Amunts and published by Springer Nature. This book was released on 2021-07-20 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book constitutes revised selected papers from the 4th International Workshop on Brain-Inspired Computing, BrainComp 2019, held in Cetraro, Italy, in July 2019. The 11 papers presented in this volume were carefully reviewed and selected for inclusion in this book. They deal with research on brain atlasing, multi-scale models and simulation, HPC and data infra-structures for neuroscience as well as artificial and natural neural architectures.
Download or read book Theory for the Development of Neuron Selectivity Orientation Specificity and Binocular Interaction in Visual Cortex written by Elie L. Bienenstock and published by . This book was released on 1981 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of stimulus selectivity in primary sensory cortex of higher vertebrates is considered in a general mathematical framework. A synaptic evolution scheme of a new kind is proposed in which incoming patterns rather than converging afferents compete. The change in efficacy of a given synapse depends not only on instantaneous pre and postsynaptic activities but also on a slowly varying time-averaged value of the postsynaptic activity. Assuming an appropriate nonlinear form for this dependence, development of selectivity is obtained under quite general conditions on the sensory environment. One does not require nonlinearity of the neuron's integrative power nor does one need to assume any particular form for intracortical circuitry. This is illustrated in simple cases, e.g. when the environment consists of only two different stimuli presented alternately in a random manner. The following formal statement then holds: the state of the system converges with probability 1 to points of maximum selectivity in the state space. We next consider the problem of early development of orientation selectivity and binocular interaction in primary visual cortex. Giving the environment an appropriate form, we obtain orientation tuning curves and ocular dominance comparable to what is observed in normally reared adult cats or monkeys. Simulations with binocular input and various types of normal or altered environments show good agreement with relevant experimental data.
