Download or read book Computational Models of Neural Circuitry in the Macaque Monkey Primary Visual Cortex written by Ute Bauer and published by Cuvillier Verlag. This book was released on 1998 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Neuron Types in Working Memory Microcircuits Along the Dorsal Visual Pathway of the Macaque Monkey written by Santiago Torres Gomez and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Working memory (WM), the ability to maintain and manipulate information over a short span of time in the absence of external sensory input, is deemed fundamental in the production of goal-directed behaviour. Previous neurophysiological studies in macaques have reported that robust sustained activity representing the contents of working memory in the absence of sensory stimuli is present in association cortices (LPFC and MST) along the dorsal visual processing stream, but is not present in sensory areas (MT). The distinctive properties of an area microcircuit that allow sustained activity to arise remain unclear. Differences in the aforementioned cortical functions may depend on circuitry properties, such as the precise relationship between excitation and inhibition underlying their network dynamics. Thus, MT does not appear to possess the proper network infrastructure to sustain persistent activation during the memory period, strictly encoding current visual input, while MST and LPFC may have specialized neural circuitry that additionally encode and maintain internally generated signals. Computational models of how sustained activity is generated have proposed that in the cortex, a microcircuit composed of 4 main cell types (excitatory pyramidal (P), and inhibitory calretinin (CR), calbindin (CB), and parvalbumin (PV) expressing interneurons) may underlie the ability to produce sustained activity. In sensory networks, neural activity is mostly driven by the contribution from peripheral sensory streams or other external sources of excitation, and does not persevere in the absence of the stimulus. These differences in circuitry may depend on differences in the balance between their intrinsic populations of inhibitory and excitatory neuron, with a predominance of excitation for reverberatory cortical circuits. One feature of PV neurons that makes their identification possible is the narrow waveform of their action potential. This feature can be used in electrophysiological recordings to identify neuron types, so that narrow spiking (NS) neurons correspond to putative inhibitory PV neurons and broadspiking (BS) neurons comprise mainly putative pyramidal neurons as well as other interneuron types. We hypothesize that the ability of a brain microcircuit to encode working memory through sustained activity correlates with changes in neuronal densities along the cortical visual pathway. Specifically, we should observe a decrease in the proportion of NS to BS neurons from areas that do not show sustained activity to areas that show robust sustained activity. In order to test this hypothesis, we recorded single cell responses from three different brain areas, MT, MST and LPFC, during a working memory task. We classified neurons according to their action potential waveforms (NS, considered as putative PV cells, and BS neurons considered as a population that contains P, CR and CB interneurons). We found that the proportion of NS/BS decrease from MT to MST to LPFC. Populations of NS and BS neurons show differences in their ability to encode sensory and mnemonic signals across the different areas. We also show that MT favours sensory coding, while MST and more so LPFC increasingly support mnemonic coding. The work here presented contributes to bridge the gap between neuronal activity and cyto-architectural models of cortical microcircuitry of functionally distinct brain areas involved in WM along the dorsal visual pathway of the macaque." --

Download or read book The Role of Macaque V1 Neurons in Spatiochromatic Processing and Behavior written by Abhishek De and published by . This book was released on 2020 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vision is critical for survival. We can easily identify objects, guide actions, and avoid collisions if our eyes are open but these abilities are severely impaired if our eyes are closed. This tremendous feat of vision appears simplistic but is implemented by complex biological processes performed by the eye and brain. Therefore, a central goal in visual neuroscience is to understand how neurons in the brain represent scenes, and how the neural activity in turn helps guide behavior. Scenes are composed of spatial and chromatic variations, herein referred to as spatiochromatic variations. In the primary visual cortex (V1) of macaque monkeys, some neurons jointly analyze edges and color, making them an ideal substrate for understanding human spatiochromatic vision. Double-opponent (DO) cells in V1 respond strongly to adjacently placed lights of opposite color and weakly to spatially uniform light of one color. These properties make them well suited for processing of color across space. However, we do not know precisely what information DO cells represent and how. Understanding how DO cells function will advance the field of visual neuroscience in three ways. First, it will help us understand how DO cells are connected to other neurons, thereby shedding light on the organization of cells in V1. Second, it will help link the neuronal responses to behavioral phenomena in color vision. Third, it will advance mathematical models of visual processing that will guide research in other fields. How information about scenes is used for behavior is incomplete without understanding the link between neural activity and behavior. A mechanistic understanding of how V1 neural activity impacts visual perception will be important for understanding the role of V1 in diseases and designing brain-machine interfaces. Using a combination of electrophysiological measurements, monkey behavior and state-of-the-art techniques, I investigated the role of V1 DO cells in the spatiochromatic processing of light, and the role of V1 neural activity in visual perception. I compared my findings about DO cells to simple cells--the best understood functional cell type in V1 that represent oriented luminance edges in scenes, and integrate signals across space roughly linearly. I pursued my research in the form of three different projects, and I report the key findings from each of the projects below. In project 1, I investigated the representation of edges by DO cells. I found that DO cells represent chromatic edges the same way as simple cells represent luminance edges. In project 2, I investigated how DO cells integrate color signals across space. I found that DO cells integrate spatial signals as linearly as simple cells meaning that both these classes of neurons simply weigh and sum the incoming light to generate a spiking response. In interpreting this result, it is important to realize that linearity is not the default mode of visual neurons but rather implies a specialized wiring. My results suggest that the specialized wiring creates linear luminance edge detectors and chromatic edge detectors in V1. Together, the results from project 1 and project 2 suggest that DO cells are similar to simple cells in many ways, and these classes of neurons have a similar mechanism of processing edges than previously thought. This property has major implications in understanding the neural circuitry of these cell classes and their contributions to image processing, which I discuss in Chapters 2 & 3. In project 3, I investigated the impact of silencing neural activity on behavior by pioneering a fast and powerful neural inactivation technique in monkey cortex. The advantage of this technique is that the neural inactivation can be reversed on a trial-by-trial basis, which was difficult to achieve previously. Inactivation of V1 led to reduced sensitivity for visual detection by monkeys suggesting that V1 neural activity impacts visual perception. This result opens doors for possible therapeutic treatments of visual impairments and investigations of many outstanding questions in the domain of perception, action and cognition, which I discuss in Chapter 4. Collectively, my research has made important strides in the field of visual neuroscience by advancing our understanding of spatiochromatic processing by DO cells, and the impact of V1 neural activity on visual perception.

Download or read book Local Circuitry and Function of Deep Layer Neurons in Monkey Primary Visual Cortex written by Farran Briggs and published by . This book was released on 2003 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exploration of Cortical Function written by M. Stetter and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploration of Cortical Function summarizes recent research efforts aiming at the revelation of cortical population coding and signal processing strategies. Topics include optical detection techniques of population activity in the sub-millimeter range, advanced methods for the statistical analysis of these data, and biologically inspired neuronal modeling techniques for population activities in the frameworks of optimal coding, statistical learning theory, and mean-field recurrent networks. Exploration of Cortical Function is unique in that it covers one complete branch of population-based brain research ranging from techniques for data acquisition over data analysis up to modeling techniques for the quantification of functional principles. The volume covers an area which is of great current interest to researchers working on cerebral cortex. The combination of models and image analysis techniques to examine the activity of large cohorts of neurons is especially intriguing and prone to considerable error and debate.

Download or read book Introductory circuitry studies of a computational model of the primary visual cortex written by Eva Sabrina Simmons and published by . This book was released on 1992 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Modelling in Behavioural Neuroscience written by Dietmar Heinke and published by Psychology Press. This book was released on 2009-04-03 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents the state-of-the-art in the field through a unique collection of papers from the world's leading researchers in the area of computational modelling in behavioural neuroscience.

Download or read book Computational and Cognitive Neuroscience of Vision written by Qi Zhao and published by Springer. This book was released on 2016-10-03 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite a plethora of scientific literature devoted to vision research and the trend toward integrative research, the borders between disciplines remain a practical difficulty. To address this problem, this book provides a systematic and comprehensive overview of vision from various perspectives, ranging from neuroscience to cognition, and from computational principles to engineering developments. It is written by leading international researchers in the field, with an emphasis on linking multiple disciplines and the impact such synergy can lead to in terms of both scientific breakthroughs and technology innovations. It is aimed at active researchers and interested scientists and engineers in related fields.

Download or read book Computational Models of Brain and Behavior written by Ahmed A. Moustafa and published by John Wiley & Sons. This book was released on 2017-09-18 with total page 845 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive Introduction to the world of brain and behavior computational models This book provides a broad collection of articles covering different aspects of computational modeling efforts in psychology and neuroscience. Specifically, it discusses models that span different brain regions (hippocampus, amygdala, basal ganglia, visual cortex), different species (humans, rats, fruit flies), and different modeling methods (neural network, Bayesian, reinforcement learning, data fitting, and Hodgkin-Huxley models, among others). Computational Models of Brain and Behavior is divided into four sections: (a) Models of brain disorders; (b) Neural models of behavioral processes; (c) Models of neural processes, brain regions and neurotransmitters, and (d) Neural modeling approaches. It provides in-depth coverage of models of psychiatric disorders, including depression, posttraumatic stress disorder (PTSD), schizophrenia, and dyslexia; models of neurological disorders, including Alzheimer’s disease, Parkinson’s disease, and epilepsy; early sensory and perceptual processes; models of olfaction; higher/systems level models and low-level models; Pavlovian and instrumental conditioning; linking information theory to neurobiology; and more. Covers computational approximations to intellectual disability in down syndrome Discusses computational models of pharmacological and immunological treatment in Alzheimer's disease Examines neural circuit models of serotonergic system (from microcircuits to cognition) Educates on information theory, memory, prediction, and timing in associative learning Computational Models of Brain and Behavior is written for advanced undergraduate, Master's and PhD-level students—as well as researchers involved in computational neuroscience modeling research.

Download or read book Computational Neuroscience Theoretical Insights into Brain Function written by Paul Cisek and published by Elsevier. This book was released on 2007-11-14 with total page 571 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational neuroscience is a relatively new but rapidly expanding area of research which is becoming increasingly influential in shaping the way scientists think about the brain. Computational approaches have been applied at all levels of analysis, from detailed models of single-channel function, transmembrane currents, single-cell electrical activity, and neural signaling to broad theories of sensory perception, memory, and cognition. This book provides a snapshot of this exciting new field by bringing together chapters on a diversity of topics from some of its most important contributors. This includes chapters on neural coding in single cells, in small networks, and across the entire cerebral cortex, visual processing from the retina to object recognition, neural processing of auditory, vestibular, and electromagnetic stimuli, pattern generation, voluntary movement and posture, motor learning, decision-making and cognition, and algorithms for pattern recognition. Each chapter provides a bridge between a body of data on neural function and a mathematical approach used to interpret and explain that data. These contributions demonstrate how computational approaches have become an essential tool which is integral in many aspects of brain science, from the interpretation of data to the design of new experiments, and to the growth of our understanding of neural function.• Includes contributions by some of the most influential people in the field of computational neuroscience• Demonstrates how computational approaches are being used today to interpret experimental data• Covers a wide range of topics from single neurons, to neural systems, to abstract models of learning

Download or read book Integrating Computational and Neural Findings in Visual Object Perception written by Judith C. Peters and published by Frontiers Media SA. This book was released on 2016-06-29 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: The articles in this Research Topic provide a state-of-the-art overview of the current progress in integrating computational and empirical research on visual object recognition. Developments in this exciting multidisciplinary field have recently gained momentum: High performance computing enabled breakthroughs in computer vision and computational neuroscience. In parallel, innovative machine learning applications have recently become available for datamining the large-scale, high resolution brain data acquired with (ultra-high field) fMRI and dense multi-unit recordings. Finally, new techniques to integrate such rich simulated and empirical datasets for direct model testing could aid the development of a comprehensive brain model. We hope that this Research Topic contributes to these encouraging advances and inspires future research avenues in computational and empirical neuroscience.

Download or read book Emergent Neural Computational Architectures Based on Neuroscience written by Stefan Wermter and published by Springer. This book was released on 2003-05-15 with total page 587 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is generally understood that the present approachs to computing do not have the performance, flexibility, and reliability of biological information processing systems. Although there is a comprehensive body of knowledge regarding how information processing occurs in the brain and central nervous system this has had little impact on mainstream computing so far. This book presents a broad spectrum of current research into biologically inspired computational systems and thus contributes towards developing new computational approaches based on neuroscience. The 39 revised full papers by leading researchers were carefully selected and reviewed for inclusion in this anthology. Besides an introductory overview by the volume editors, the book offers topical parts on modular organization and robustness, timing and synchronization, and learning and memory storage.

Download or read book Functional Anatomy of Visual Processing in the Cerebral Cortex of the Macaque written by Koen Nelissen and published by Leuven University Press. This book was released on 2006 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we examined the monkey cortical regions involved in processing of color, visual motion information, and the recognition of actions done by others. The aim was to gain better insight in the functional organization of the monkey visual cortex using in-house developed functional imaging techniques. Two different functional imaging techniques were used in these studies, the double-label deoxyglucose technique (DG) and functional magnetic resonance imaging (fMRI) in the awake monkey (Chapter 2). Both techniques allow to obtain an overview of stimulus-related neural activity throughout the whole brain, integrated over a limited amount of time. The results of the color experiments (Chapter 3) clearly showed that color related information is processed within a group of areas belonging to the ventral stream, which is involved in the perception of objects. Color-related metabolic activity was observed in visual areas V1, V2, V3, V4 and inferotemporal cortex (area TEO and TE). These findings set to rest the longstanding controversial claims that color would be processed almost selectively in one extrastriate visual area (V4) (Zeki SM, Brain Res 1973 53: 422-427). These results also show the usefulness of whole brain functional mapping techniques, as a complimentary approach to single cell measurements. In Chapter 4, we investigated which regions in the superior temporal sulcus (STS) of the monkey are involved in the analysis of motion. While the caudal part of the STS has been studied extensively, including area MT/V5 and MST, little is known about motion sensitivity in more anterior-ventral STS regions. Using fMRI, we were able to localize and delineate six different motion sensitive regions in the STS. One of these regions, that we termed 1st (lower superior temporal), had not been described so far. We were able to further characterize the six motion sensitive regions, using a wide variety of motion-sensitivity tests. The results of the latter tests suggested that motion related information might be processed along a second pathway within the STS, in addition to the MT-MST path (which is involved in the perception of heading). This second pathway, which includes the more rostral motion sensitive STS regions (FST, 1st and STPm) is possibly involved in the visual processing of biological movements (movements of animate objects) and actions. Finally, we investigated how and where in the monkey brain visual information about actions done is processed (Chapter 5 and 6). We found (Chapter 5) that, in agreement with earlier single unit results, the observation of grasping movements activates several regions in the premotor cortex of the monkey. Remarkable is that these premotor regions predominantly have a motor function, coding different types of higher order motor acts (for instance grasping of an object). These results are in agreement with earlier suggestions that we are able to understand actions done by others, because observation of a particular motor act activates our own motor representation of the same act. Furthermore, these studies suggested that within the frontal cortex of the monkey, there is a distinction between context-dependent (a person grasping) and more abstract (a hand grasping) action representations. In Chapter 6 we studied two other regions which are involved in the processing of visual information of actions done by others, the superior temporal sulcus (STS) and the parietal cortex. In the parietal cortex, we found a similar distinction between context-dependent and more abstract action representations as observed in prefrontal cortex. These results suggest that the parietal cortex is not only involved in the visual control of action planning, but also in the visual processing of actions performed by others. Based upon anatomical connections between the STS, parietal and frontal regions and motion-, form- and action-related functional properties of the former regions, we tentatively suggest how information about actions done by others might be sent from the STS to the frontal cortex along three different pathways. The latter working hypothesis will be tested in the future by additional fMRI control experiments and by combining fMRI, inactivation and microstimulation experiments while monkeys perform grasping tasks and/or view actions performed by others.

Download or read book Computational Models of Visual Processing written by Michael S. Landy and published by MIT Press. This book was released on 1991 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: The more than twenty contributions in this book, all new and previously unpublished, provide an up-to-date survey of contemporary research on computational modeling of the visual system. The approaches represented range from neurophysiology to psychophysics, and from retinal function to the analysis of visual cues to motion, color, texture, and depth. The contributions are linked thematically by a consistent consideration of the links between empirical data and computational models in the study of visual function. An introductory chapter by Edward Adelson and James Bergen gives a new and elegant formalization of the elements of early vision. Subsequent sections treat receptors and sampling, models of neural function, detection and discrimination, color and shading, motion and texture, and 3D shape. Each section is introduced by a brief topical review and summary. ContributorsEdward H. Adelson, Albert J. Ahumada, Jr., James R. Bergen, David G. Birch, David H. Brainard, Heinrich H. Bülthoff, Charles Chubb, Nancy J. Coletta, Michael D'Zmura, John P. Frisby, Norma Graham, Norberto M. Grzywacz, P. William Haake, Michael J. Hawken, David J. Heeger, Donald C. Hood, Elizabeth B. Johnston, Daniel Kersten, Michael S. Landy, Peter Lennie, J. Stephen Mansfield, J. Anthony Movshon, Jacob Nachmias, Andrew J. Parker, Denis G. Pelli, Stephen B. Pollard, R. Clay Reid, Robert Shapley, Carlo L. M. Tiana, Brian A. Wandell, Andrew B. Watson, David R. Williams, Hugh R. Wilson, Yuede. Yang, Alan L. Yuille

Download or read book Computational Maps in the Visual Cortex written by Risto Miikkulainen and published by Springer Science & Business Media. This book was released on 2006-01-16 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: For more than 30 years, the visual cortex has been the source of new theories and ideas about how the brain processes information. The visual cortex is easily accessible through a variety of recording and imagining techniques and allows mapping of high level behavior relatively directly to neural mechanisms. Understanding the computations in the visual cortex is therefore an important step toward a general theory of computational brain theory.

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.