Download or read book The Visually Responsive Neuron written by T. Philip Hicks and published by Elsevier. This book was released on 1993 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely new volume presents broad-based and wide-ranging contributions on all aspects of vision. The material is grouped for presentation in a logical fashion in five main themes: peripheral processing; sensory integration in superior colliculus; organization of visual projections; development and plasticity; and neuronal encoding and visually guided behavior. The material spans from molecules to cognition, including overt behavior, and synaptic and membrane levels of analysis. The species studied also range over diverse phyla, while contributors too form a diverse group representing Europe, North America, and Asia. The Visually Responsive Neuron is an exciting and informative addition to the well known Progress in Brain Research series.
Download or read book The Visually Responsive Neuron written by T.P. Hicks and published by Elsevier. This book was released on 1993-03-18 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely new volume presents broad-based and wide-ranging contributions on all aspects of vision. The material is grouped for presentation in a logical fashion in five main themes: peripheral processing; sensory integration in superior colliculus; organization of visual projections; development and plasticity; and neuronal encoding and visually guided behavior. The material spans from molecules to cognition, including overt behavior, and synaptic and membrane levels of analysis. The species studied also range over diverse phyla, while contributors too form a diverse group representing Europe, North America, and Asia. The Visually Responsive Neuron is an exciting and informative addition to the well known Progress in Brain Research series.
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 Central Processing of Visual Information A Integrative Functions and Comparative Data written by H. Autrum and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume covers the physiology of the visual system beyond the optic nerve. It is a continuation of the two preceding parts on the photochemistry and the physiology of the eye, and forms a bridge from them to the fourth part on visual psychophysics. These fields have all developed as independent speciali ties and need integrating with each other. The processing of visual information in the brain cannot be understood without some knowledge of the preceding mechanisms in the photoreceptor organs. There are two fundamental reasons, ontogenetic and functional, why this is so: 1) the retina of the vertebrate eye has developed from a specialized part of the brain; 2) in processing their data the eyes follow physiological principles similar to the visual brain centres. Peripheral and central functions should also be discussed in context with their final synthesis in subjective experience, i. e. visual perception. Microphysiology and ultramicroscopy have brought new insights into the neuronal basis of vision. These investigations began in the periphery: HARTLINE'S pioneering experiments on single visual elements of Limulus in 1932 started a successful period of neuronal recordings which ascended from the retina to the highest centres in the visual brain. In the last two decades modern electron microscopic techniques and photochemical investigations of single photoreceptors further contributed to vision research.
Download or read book Neuronal Operations in the Visual Cortex written by G.A. Orban and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: The invitation by the editors of the series "studies of brain function" to contribute a monograph on the visual cortex gives me the opportunity to present in a concentrated manner much of the work I have done on the visual cortical areas of cat and monkey. However, the field of visual cortical physi ology is so active and so diverse that the presentation of only my own work would have given a very incomplete view of visual cortical functioning. Therefore this monograph also reviews most of the studies carried out on the subject in the last two decades. Where possible I have tried not only to describe the cortical machinery but also its possible functional purpose regarding vision. In doing this I have expressed my personal views rather than just reviewing the experimental facts. Much of the work presented in this monograph has been supported by the National Research Council of Belgium and the Research Council of the Catholic University of Leuven. I express my gratitude to them. I have en joyed collaborating in these studies with P. O. Bishop, H. Kato, H. Kennedy, K. P. Hoffmann, H. Maes, J. Duysens, E. Vandenbussche, and H. van der Glas. I am much indebted to all those who have commented on earlier versions of this monograph: J. Allman, H. Barlow, J. BuBier, M. Callens, J. Duysens, O. J. Griisser, P. Heggelund, H. Kennedy, L. C. Orban and L. Palmer.
Download or read book Behavioral State Modulates Primary Visual Cortex Responsiveness in Mice written by Michael Einstein and published by . This book was released on 2017 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain is constantly bombarded with sensory stimuli. In order to process and perceive such diverse information streams simultaneously, the brain prioritizes information relevant to an animal's current behavioral needs. In this thesis, I investigate the neural mechanisms that enable the brain to increase or decrease visual signals depending on an animal's behavioral state. In chapter 1, I illustrate a novel mechanism, 3-5 Hz membrane potential (Vm) oscillations, that decreases the responsiveness of neurons in the primary visual cortex (V1) of mice. Using 2-photon guided whole-cell recordings as mice passive viewed and actively engaged drifting sine-wave gratings, I discovered that these visually-evoked phenomena were not influenced by changes in arousal or animal movement, but their timing was influenced by an animal's behavioral state. In addition to uncovering a novel mechanism for reducing the responsiveness of neurons in the brain, this chapter substantially furthers the field's knowledge of how behavior and arousal affect the membrane potential of neurons in the cerebral cortex. In chapter 2, I develop a method to train animals how to perform a visual attention task. I describe the hardware and software tools used to actuate the task and the method used to train the animals. Using the method outlined in this chapter, I was able to routinely train animals to perform a multimodal attention task with approximately one month of training. In chapter 3, I employed this new attention model and, using 2-photon guided whole-cell recordings in behaving animals, I discovered that attention boosts the depolarization associated with visual stimulation in layer 2/3 V1 neurons, illustrating a potential mechanism that causes neurons to be more responsive to visual cues during attention. Finally, using 128 channel silicon nanoprobes chronically implanted in V1, I verified that the attention task increased the responsiveness of V1 neurons and desynchronized the local network in mice, replicating results previously obtained in non-human primate models and setting the groundwork for future study. As a result, my thesis details novel neural mechanisms for enhancing or dampening visual signals and expands our knowledge of how the brain prioritizes information according to an animal's behavioral context.
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 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 An Introduction to the Visual System written by Martin J. Tovée and published by Cambridge University Press. This book was released on 2008-07-03 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on the successful formula of the first edition, Martin Tovée offers a concise but detailed account of how the visual system is organised and functions to produce visual perception. He takes his readers from first principles; the structure and function of the eye and what happens when light enters, to how we see and process images, recognise patterns and faces, and through to the most recent discoveries in molecular genetics and brain imaging, and how they have uncovered a host of new advances in our understanding of how visual information is processed within the brain. Incorporating new material throughout, including almost 50 new images, every chapter has been updated to include the latest research, and culminates in helpful key points, which summarise the lessons learnt. This book is an invaluable course text for students within the fields of psychology, neuroscience, biology and physiology.
Download or read book V1 Neurons Sense Eye Movements During Smooth Pursuit written by Jie Shao and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The function of the primary visual cortex (V1) has been extensively explored by electrophysiological recordings under passive viewing conditions. In recent years, the importance of exploring V1 function during active visual perception has been increasingly recognized. Notably, electrophysiological studies from awake behaving primates have demonstrated that visual stimulus processing in V1 is modulated by saccadic (rapid) eye movements. However, to date, we have a poor understanding of V1 neuronal responses in the context of other voluntary gaze movements, for instance, smooth pursuit gaze movements. In this thesis, a novel experimental design was used to investigate V1 neural response to a visual stimulus during smooth pursuit gaze movement (either by eye pursuit alone or by a combination of eye and head pursuit). A cynomolgus monkey was trained to actively perform horizontal smooth pursuit elicited by step-ramp target trajectories (0, 20°/s, 40°/s, 60°/s) of a fixation target, while single V1 neuronal responses were recorded in response to a drifting grating stimulus in the neuron's receptive field. To prevent a velocity mismatch between gaze pursuit and the visual stimulus, the position of the stimulus was adjusted online in a frame-based manner (60 Hz) according to the on-going gaze position, so as to keep the stimulus stabilized within the neuron's receptive field. The results revealed that, in conditions where the monkey generated smooth pursuit eye movements, neural responses exhibited an initial suppression around 100 - 200ms followed by an enhancement between 200 - 350ms, after stimulus onset. The initial suppression produced by smooth pursuit eye movement was reached earlier for the highest tracking velocity (i.e., 60°/s). In contrast, the timing of the subsequent enhancement did not change across pursuit velocities. Furthermore, the results also provide evidence that V1 neurons may signal the onset of head movement - V1 neurons demonstrated a response for the initiation of head motion during coordinated eye and head pursuit movement. Taken together, these results have revealed a clear modulatory effect on V1 visual processing from smooth pursuit gaze movement, suggesting that the visual system combines extra-retinal information about both eye and head movement to help maintain a perceptually stable world." --
Download or read book Neural Mechanisms of Color Vision written by Bevil Richard Conway and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr. Conway mapped the spatial and temporal structure of the cone inputs to single neurons in the primary visual cortex of the alert macaque. Color cells had receptive fields that were often Double-Opponent, an organization of spatial and chromatic opponency sufficient to form the basis for color constancy and spatial color contrast. Almost all color cells gave a bigger response to color when preceded by an opposite color, suggesting that these cells also encode temporal color contrast. In sum, color perception is likely subserved by a subset of specialized neurons in the primary visual cortex. These cells are distinct from those that likely underlie form and motion perception. Color cells establish three color axes sufficient to describe all colors; moreover these cells are capable of computing spatial and temporal color contrast - and probably contribute to color constancy computations - because the receptive fields of these cells show spatial and temporal chromatic opponency.
Download or read book An Analysis of Neuronal Receptive Fields at Three Stages of Visual Processing written by Joshua Paul Van Kleef and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visual neurons must efficiently encode visual information that is relevant to the animals' behaviour in an ever-changing visual environment. One of the ways animals are able to adapt to these changes is to alter their behaviour. Another, the topic of this thesis is to alter the processing properties of their visual neurons. I investigate the effect of changing the stimulus on the response properties of single neurons at three stages of visual processing. A reverse-correlation technique is used to measure spatiotemporal receptive fields (STRFs) which measure how the neuron spatially and temporally integrates the linear and nonlinear contrast stimuli presented to it in space and time.This analysis is performed for stimuli with different contrast, colour and sparsity and the changes in the STRFs are analysed in terms of their ability to improve neural performance. I study the processing of ultraviolet (UV) and green light in photoreceptors of an insect simple-lens eye, the median (middle) ocellus of a dragonfly. For the first time I present physiological evidence which shows these eyes are capable of a moderate level of spatial resolution and reveal differences in the way UV and green light sequences are processed. At the next level of processing, large second-order ocellar neurons (L-neurons) were studied. By presenting monochromatic (UV or green) moving bars and gratings I demonstrate, for the first time, that ocellar L-neurons are directionally selective in UV light but not in green light. Using a novel random stimulus I show that for most L-neurons the linear STRFs alter in structure significantly with changes in the stimulus density. With decreases in the stimulus density these cells become lower latency, have better spatial resolution and are spatiotemporally tuned to faster velocities. These new STRFs account significantly better for the response of L-neurons to fast moving bars.In the last section of my thesis I investigate whether the visual stimulus can also influence the receptive fields of neurons further along the visual pathway. To achieve this goal I map the changes in spatiotemporal tuning with changes in contrast of a subset of neurons within the cat primary visual cortex. I provide further evidence that at low contrasts, particular types of neurons, known as complex cells, have response properties similar to the other major type of cortical neuron, simple-cells. These results are combined with theoretical modelling to investigate the theory that complex STRFs are composed of simple-cell components.In summary, this thesis demonstrates at three levels of visual processing how neural STRFs are altered depending on the properties of the stimulus that is driving their response.
Download or read book Circuitry Underlying Response Properties of Neurons in the Primary Visual Cortex Spatiotemporal Receptive Field of Synaptic Inputs written by Chenmei Jennie Chen and published by . This book was released on 2009 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Visual Brain in Action written by David Milner and published by Oxford University Press. This book was released on 2006-10-12 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1995, this book presents a model for understanding the visual processing underlying perception and action, proposing a broad distinction within the brain between two kinds of vision: conscious perception and unconscious 'online' vision.
Download or read book Comprehensive Developmental Neuroscience Neural Circuit Development and Function in the Heathy and Diseased Brain written by B.E. Stein and published by Elsevier Inc. Chapters. This book was released on 2013-05-06 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioelectric Recording Techniques written by Michael M. Patterson and published by . This book was released on 1973 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visual Cortex written by Stephane Molotchnikoff and published by BoD – Books on Demand. This book was released on 2012-09-26 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neurosciences have experienced tremendous and wonderful progress in many areas, and the spectrum encompassing the neurosciences is expansive. Suffice it to mention a few classical fields: electrophysiology, genetics, physics, computer sciences, and more recently, social and marketing neurosciences. Of course, this large growth resulted in the production of many books. Perhaps the visual system and the visual cortex were in the vanguard because most animals do not produce their own light and offer thus the invaluable advantage of allowing investigators to conduct experiments in full control of the stimulus. In addition, the fascinating evolution of scientific techniques, the immense productivity of recent research, and the ensuing literature make it virtually impossible to publish in a single volume all worthwhile work accomplished throughout the scientific world. The days when a single individual, as Diderot, could undertake the production of an encyclopedia are gone forever. Indeed most approaches to studying the nervous system are valid and neuroscientists produce an almost astronomical number of interesting data accompanied by extremely worthy hypotheses which in turn generate new ventures in search of brain functions. Yet, it is fully justified to make an encore and to publish a book dedicated to visual cortex and beyond. Many reasons validate a book assembling chapters written by active researchers. Each has the opportunity to bind together data and explore original ideas whose fate will not fall into the hands of uncompromising reviewers of traditional journals. This book focuses on the cerebral cortex with a large emphasis on vision. Yet it offers the reader diverse approaches employed to investigate the brain, for instance, computer simulation, cellular responses, or rivalry between various targets and goal directed actions. This volume thus covers a large spectrum of research even though it is impossible to include all topics in the extremely diverse field of neurosciences.
