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Modeling Receptive Field Properties Of Cat Visual Pathway Neurons Through Spatial And Temporal Population Interactions
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Book Synopsis Modeling Receptive Field Properties of Cat Visual Pathway Neurons Through Spatial and Temporal Population Interactions by : Maureen Ann Valerie Gremillion
Download or read book Modeling Receptive Field Properties of Cat Visual Pathway Neurons Through Spatial and Temporal Population Interactions written by Maureen Ann Valerie Gremillion and published by . This book was released on 1995 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Y Visual Pathway of the Cat by : Chun-I. Yeh
Download or read book The Y Visual Pathway of the Cat written by Chun-I. Yeh and published by . This book was released on 2006 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Study of Receptive Fields on Neurons of Cat's Visual Cortex as Filters of Spatial Frequency by : V. D. Glezer
Download or read book A Study of Receptive Fields on Neurons of Cat's Visual Cortex as Filters of Spatial Frequency written by V. D. Glezer and published by . This book was released on 1974 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The striation of a stimulus passing across a complex or supercomplex receptive field of a cat's visual cortex (RFVC) defines the characteristics of the field's responses. For each RF (receptive field) an optimum stimulus which evokes a maximum response can be found. The more bands there are in the optimum stimulus, the smaller is the average width of bars and the intervals between them. The effective areas of the stimulus is independent of the number of bands it contains and is equal to 2.6 degrees on the average (in diameter). The column of neurons with identical orientation of the RFs contains fields in which optimum stimuli consist of a different number of bands. These data lead one to assume that the RFVC are narrow-band filters of spatial frequencies and perform a piecewise Fourier transform of the image. A network of such neurons will discern the boundary between textures.
Book Synopsis Central/peripheral Receptive Field Characteristics of Neurons in Normal and Monocularly-deprived Cat Striate Cortex by : James Roland Wilson
Download or read book Central/peripheral Receptive Field Characteristics of Neurons in Normal and Monocularly-deprived Cat Striate Cortex written by James Roland Wilson and published by . This book was released on 1976 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Analysis of Neuronal Receptive Fields at Three Stages of Visual Processing by : Joshua Paul Van Kleef
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.
Book Synopsis The Construction of the Receptive Field Properties of Cells in the Cat Visual Cortex from the Synaptic Inputs to the Cortex by : Bharathi Jagadeesh
Download or read book The Construction of the Receptive Field Properties of Cells in the Cat Visual Cortex from the Synaptic Inputs to the Cortex written by Bharathi Jagadeesh and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Nonlinear Subunit Models of Neuronal Receptive Fields in the Early Visual Pathway by : Amol Gharat
Download or read book Nonlinear Subunit Models of Neuronal Receptive Fields in the Early Visual Pathway written by Amol Gharat and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Our visual system is sensitive to boundaries defined by differences in cues such as luminance (first-order cue), as well as texture, contrast, or motion (second-order cues). Gradients in these cues can be utilized to perform tasks such as figure-ground segregation and 3D shape perception. A significant fraction of neurons in the early visual cortex of cats and monkeys have been shown to be selective to both first- and second-order boundaries. These neurons are thought to be the neural correlate for perceptual encoding of such boundaries. They are selective for the same boundary orientation irrespective of the cue (first- or second-order) that defines it ("form cue-invariance"), which makes these neurons powerful candidates for the task of segmentation. However, the neural circuitry that gives rise to this selectivity for the early stages of visual processing remains unclear. To address this question, I perform neurophysiological recordings at the early stages of the visual pathway in cats, and then build biologically inspired neural circuit models that can account for visual response properties of neurons at subcortical as well as early cortical stages. In Chapter 2, I use multi-electrode recordings to demonstrate the presence of a significant fraction of neurons in cat Area 18 with nonlinear receptive fields like those of subcortical Y-type cells. These neurons have receptive field properties intermediate between subcortical Y cells and cortical orientation selective cue-invariant neurons. These are strong candidates for building cue-invariant orientation-selective neurons. Furthermore I present a novel neural circuit model that pools such Y-like neurons in an unbalanced "push-pull" manner, to generate orientation-selective cue-invariant receptive fields.In Chapter 3, I estimate biologically constrained neural network models of cat LGN receptive fields using recent machine learning methods (deep learning). The receptive fields are modeled as arising from a two-stage convolutional neural network model. The first stage, corresponding to retinal bipolar cell subunits, is modeled as a convolutional filter layer, and the second stage is modeled as a pooling layer. These two layers are separated by an intermediate parametric nonlinearity. I train such a neural network model for each recorded LGN neuron, using its spiking responses to naturalistic texture stimuli. These models are not only better in comparison to the standard linear-nonlinear models at predicting response to arbitrary stimuli, but they also recover biologically interpretable subunit models.In chapter 4, I evaluate the integration of ON- and OFF-pathway inputs by individual neurons in early cortical areas of the cat (Area 17 and Area 18). In this study, I model receptive fields of cortical simple cells as a linear weighted sum of rectified inputs from model ON- and OFF-center LGN afferents, with the weights estimated using a regression framework. The estimated models reveal significant asymmetries in spatiotemporal integration of ON and OFF signals within simple cell receptive fields. These observed asymmetries could provide the neural mechanism for generating cue-invariant receptive fields from Y-pathway inputs.In summary, I put together our knowledge of retinal as well as early cortical processing to show how spatial nonlinearities emerging from the retina could provide an essential basis for cortical visual processing. I further evaluate these neural mechanisms by estimating single neuron receptive field models, using modern system identification methods. Finally I propose, and provide supportive evidence for, a novel neural circuit mechanism that could explain the cue-invariant processing of luminance- and texture-defined boundaries through a common pathway." --
Book Synopsis Spatial and Temporal Receptive Field Properties in the Primary Visual Cortex of Tree Shrew ("tupaia Belangeri") by : Julia Veit
Download or read book Spatial and Temporal Receptive Field Properties in the Primary Visual Cortex of Tree Shrew ("tupaia Belangeri") written by Julia Veit and published by . This book was released on 2013 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Characterizing the Spatial and Temporal Frequency Tuning Properties in Mouse Visual Cortex with Calcium Imaging by : Natalia Mesa
Download or read book Characterizing the Spatial and Temporal Frequency Tuning Properties in Mouse Visual Cortex with Calcium Imaging written by Natalia Mesa and published by . This book was released on 2021 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the neocortex, neurons with similar functional properties are clustered together. While incompletely understood, this feature of cortical organization is conserved across a variety of species and sensory systems. In the visual cortex, neurons with similar receptive field properties lie close by in cortical space. The mouse has become an increasingly popular model organism to study vision. While mice lack the visual acuity of primates, there are unparalleled genetic tools available in mice that allow us to dissect the functional properties and connectivity of specific cell types. Mice use vision perform complex behavioral tasks, like hunt, and, like primates, their visual areas are organized hierarchically. While it is likely that mouse visual areas specialized to aid mice in performing visual tasks, there is also evidence that visual computation is different in mice and primates. In particular, visual tuning properties are mapped differently in primates and mice and this likely has relevant functional consequences. A hallmark of primate vision is the specialization of visual areas. The primate visual system is organized hierarchically such that receptive fields of neurons in higher visual areas become increasingly complex and specific. It is unknown to what extent a similar organization exists in mice. The functional role of mouse higher visual areas, and their homology to primate visual areas, is an active area of investigation. Understanding the differences and similarities between mice and primates is crucial to establishing the mouse as a relevant model organism for primate vision. Five previous studies have revealed that mouse higher visual areas have distinct spatial and temporal frequency tuning properties than primary visual area, V1. However, their findings have varied widely. Similarly, previous studies have also revealed that functional properties, mainly spatial frequency tuning and coherent motion tuning, change across the visual field, but this is under-characterized. The primary aim of my thesis was to study how receptive field properties are mapped across the mouse visual cortex and how tuning properties change across the visual field. The next is to understand how experimental conditions and experimental design choices can lead to different tuning measurements between studies. In my first project, I used a combination of widefield and 2-photon (2P) calcium imaging to investigate how spatial frequency (SF) and temporal frequency (TF) tuning properties are mapped in the mouse visual cortex. I found evidence of functional specialization at different receptive field altitude locations in V1 and higher visual areas. Neurons in anterior V1 (lower visual field of view) have lower average TF and SF tuning than posterior V1 (upper visual field of view). I measured whether tuning gradients, gradual changes in tuning properties across a visual area or areas, in V1 and higher visual areas were consistent across cortical layers and in thalamic (dLGN) axons. In most visual areas, gradients had the same slope with respect to altitude. Interestingly, I found TF gradients that did not change abruptly across areal borders. While TF tuning differed across cortical layers, the relationship between TF and altitude was consistent across laminar populations and in dLGN axons. Therefore, gradients in V1 and some higher visual areas likely result from input from dLGN axons. In my second project, I examined how different inclusion criteria can impact reported tuning properties. Neurophysiology studies require the use of inclusion criteria to identify neurons responsive to the experimental stimuli. Five recent studies used calcium imaging to measure the preferred tuning properties of layer 2/3 pyramidal neurons in mouse visual areas. These five studies used different experimental designs that employed different inclusion criteria and report different, sometimes conflicting results. Experimental design choices and inclusion criteria both affect the subpopulation of neurons that are selected for. Here, I examined how different inclusion criteria can impact reported tuning properties, modifying inclusion criteria to select different sub-populations from the same dataset of almost 17,000 layer 2/3 neurons from the Allen Brain Observatory. The choice of inclusion criteria greatly affected the mean tuning properties of the resulting sub-populations; indeed, the differences in mean tuning due to inclusion criteria were often of comparable magnitude to the differences between studies. In particular, the mean preferred TFs of visual areas changed markedly with inclusion criteria, such that the rank ordering of visual areas based on their TF preferences changed with the percentage of neurons included. These results demonstrate that the current understanding of the functional organization of the mouse visual cortex obtained from previous experiments critically depends on the inclusion criteria used.Collectively, my research has advanced our understanding of visual processing in the mouse.
Book Synopsis Analysis of Physiological Systems by : Vasilis Marmarelis
Download or read book Analysis of Physiological Systems written by Vasilis Marmarelis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: In studying physiological systems bioscientists are continually faced with the problem of providing descriptions of cause-effect relationships. This task is usually carried out through the performance of stimulus-response experiments. In the past, the design of such experiments has been ad hoc, incomplete, and certainly inefficient. Worse yet, bioscientists have failed to take advantage of advances in fields directly related to their problems (specifically, advances in the area of systems analysis). The raison d'etre of this book is to rectify this deficiency by providing the physiologist with methodological tools that will be useful to him or her in everyday labora tory encounters with physiological systems. The book was written so that it would be practical, useful, and up-to date. With this in mind, parts of it give step-by-step descriptions of in the laboratory. It is hoped that this systematic procedures to be followed will increase the usefulness of the book to the average research physiologist and, perhaps, reduce the need for in-depth knowledge of some of the associated mathematics. Even though the material deals with state-of-the art techniques in systems and signal analysis, the mathematical level has been kept low so as to be comprehensible to the average physiologist with no extensive training in mathematics. To this end, mathematical rigor is often sacrificed readily to intuitive simple arguments.
Download or read book Research Awards Index written by and published by . This book was released on 1988 with total page 874 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:
Book Synopsis Encyclopedia of Computational Neuroscience by : Dieter Jaeger
Download or read book Encyclopedia of Computational Neuroscience written by Dieter Jaeger and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling of Visual Cognition, Body Sense, Motor Control and Their Integrations by : Hong Qiao
Download or read book Modeling of Visual Cognition, Body Sense, Motor Control and Their Integrations written by Hong Qiao and published by Frontiers Media SA. This book was released on 2017-04-25 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interdisciplinary studies between neuroscience and information science have greatly promoted the development of these two fields. The achievements of these studies can help humans understand the essence of biological systems, provide computational platforms for biological experiments, and improve the intelligence and performance of the algorithms in information science. This research topic is focused on the computational modeling of visual cognition, body sense, motor control and their integrations. Firstly, the modeling and simulation of vision and body sense are achieved by 1) understanding neural mechanism underlying sensory perception and cognition, and 2) mimicking accordingly the structures and mechanisms of their signal propagation pathways. The achievement of this procedure could provide neural findings for better encoding and decoding visual and somatosensory perception of humans, and help robots or systems build humanoid robust vision, body sensing, and various emotions. Secondly, the modeling and simulation of the motor system of the primate are achieved by mimicking the coordination of bones, muscles and joints and the control mechanisms of the neural system in the brain and spinal cord. This procedure could help robots achieve fast, robust and accurate manipulations and be used for safe human-computer interaction. Finally, by integrating them, more complete and intelligent systems/robots could be built to accomplish various tasks self-adaptively and automatically.
Book Synopsis Biologically Inspired Computer Vision by : Gabriel Cristobal
Download or read book Biologically Inspired Computer Vision written by Gabriel Cristobal and published by John Wiley & Sons. This book was released on 2015-08-31 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the state-of-the-art imaging technologies became more and more advanced, yielding scientific data at unprecedented detail and volume, the need to process and interpret all the data has made image processing and computer vision increasingly important. Sources of data that have to be routinely dealt with today's applications include video transmission, wireless communication, automatic fingerprint processing, massive databanks, non-weary and accurate automatic airport screening, robust night vision, just to name a few. Multidisciplinary inputs from other disciplines such as physics, computational neuroscience, cognitive science, mathematics, and biology will have a fundamental impact in the progress of imaging and vision sciences. One of the advantages of the study of biological organisms is to devise very different type of computational paradigms by implementing a neural network with a high degree of local connectivity. This is a comprehensive and rigorous reference in the area of biologically motivated vision sensors. The study of biologically visual systems can be considered as a two way avenue. On the one hand, biological organisms can provide a source of inspiration for new computational efficient and robust vision models and on the other hand machine vision approaches can provide new insights for understanding biological visual systems. Along the different chapters, this book covers a wide range of topics from fundamental to more specialized topics, including visual analysis based on a computational level, hardware implementation, and the design of new more advanced vision sensors. The last two sections of the book provide an overview of a few representative applications and current state of the art of the research in this area. This makes it a valuable book for graduate, Master, PhD students and also researchers in the field.
Book Synopsis Visual Population Codes by : Nikolaus Kriegeskorte
Download or read book Visual Population Codes written by Nikolaus Kriegeskorte and published by MIT Press. This book was released on 2012 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: How visual content is represented in neuronal population codes and how to analyze such codes with multivariate techniques. Vision is a massively parallel computational process, in which the retinal image is transformed over a sequence of stages so as to emphasize behaviorally relevant information (such as object category and identity) and deemphasize other information (such as viewpoint and lighting). The processes behind vision operate by concurrent computation and message passing among neurons within a visual area and between different areas. The theoretical concept of "population code" encapsulates the idea that visual content is represented at each stage by the pattern of activity across the local population of neurons. Understanding visual population codes ultimately requires multichannel measurement and multivariate analysis of activity patterns. Over the past decade, the multivariate approach has gained significant momentum in vision research. Functional imaging and cell recording measure brain activity in fundamentally different ways, but they now use similar theoretical concepts and mathematical tools in their modeling and analyses. With a focus on the ventral processing stream thought to underlie object recognition, this book presents recent advances in our understanding of visual population codes, novel multivariate pattern-information analysis techniques, and the beginnings of a unified perspective for cell recording and functional imaging. It serves as an introduction, overview, and reference for scientists and students across disciplines who are interested in human and primate vision and, more generally, in understanding how the brain represents and processes information.
Download or read book The Journal of Neuroscience written by and published by . This book was released on 1995 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:
