Download or read book Functional Organisation of the Human Visual Cortex written by Balazs Gulyas and published by Elsevier Health Sciences. This book was released on 1993-05-18 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Organisation of the Human Visual Cortex

Download or read book Functional Organisation of Human Visual Cortex written by Balázs Gulyás and published by . This book was released on 1993 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating the Functional Organisation of Human Visual Cortex Using Ultra high Resolution FMRI written by Sarah Finnegan and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neuromagnetic Investigations of Functional Organisation Within Human Visual Cortex written by Fiona Catherine Fylan and published by . This book was released on 1995 with total page 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 Language written by Giovanna Zardini and published by John Libbey Eurotext. This book was released on 2006 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive monograph updates progress in understanding children's language learning and its pathologies. It stresses the neurologic basis of normal language acquisition and the consequences of a variety of disorders using such tools as detailed analysis of language comprehension, production and use, as well as functional brain imaging and electrophysiology. It also underlines the import6ance of subcortical circuitry and inner speech and reviews the unfolding or regression of language of language in focal brain lesions, autism, Williams syndrome and developmental disorders of oral and written language.

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 Functional Organization of the Ventral Temporal Cortex written by Jason M. Webster and published by . This book was released on 2018 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many complex aspects of human visual perception and recognition take place in the ventral temporal cortex; however, the functional organization of this region remains unknown. Much of the brain has been found to consist of discrete cortical areas which are distinguishable by various aspects of cortical organization, including functional properties. In the ventral temporal cortex, only a handful of visual category-selective areas have been found which collectively constitute a minority of the region. This thesis addresses two issues regarding the ventral temporal cortex. The first is an investigation of the development of known category-selective regions through a review of neural plasticity and an empirical study of a subject with a unique developmental history. The second is an approach to functionally parcellating the ventral temporal cortex, which surveys other approaches to parcellating the ventral temporal cortex and then introduces a novel data-driven method for identifying cortical functional organization.

Download or read book Anatomical and Functional Organization of the Visual Cortex and the Effect of Visual Deprivation in Animal Models written by Adrian K. Andelin and published by . This book was released on 2018 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the fact that the visual system has been the most well-studied of all sensory systems, many questions remain in regard to its structure and function in both human and animal models. While a basic blueprint of the visual system exists across all animal species that sets in place the basic structure prior to the onset of visual experience, it has been well established that this system becomes fine-tuned through experience early in life. Using a variety of techniques and animal models, this dissertation addresses some questions regarding the functional organization and the effect of visual deprivation on the visual cortex of several animal models. Rodents offer several advantages for studying various aspects of the development, organization and plasticity of the visual system. An important model for studies of visual cortex plasticity is the system of ocular dominance columns (ODC, aggregates of cells with the same eye preference), which have been extensively studied in many carnivores and primates, but have been thought not to exist in rodents. Our lab recently reported the existence of ODCs in pigmented, Long Evans rats (Laing et al. 2015), but previous reports in albino rats (Diao et al., 1983) point to differences in the binocularity of certain regions of primary visual cortex (V1) and in the role that callosal connections may have in these differences. To explain these strain differences, we hypothesized that albino rats, unlike Long Evans rats, do not have ODCs, and that callosal connections in V1 of albino rats are not patchy, as they are in Long Evans rats. In the first chapter of this dissertation, we present anatomical and electrophysiological experiments supporting our prediction that input from both eyes intermix in the binocular region of V1 in albino rats, without segregating into ODCs, and that callosal connections in albino rats are homogeneously distributed in V1. In the second chapter, we explore the effect of loss of vision during early development on the surface area of V1. Using histological methods as well as MRI techniques, we examined how the reduction in mature brain surface area varies with age when blindness occurs in rats, ferrets and humans. To compare data across species, we translated the post-conception ages of each species to a common neurodevelopmental event-time scale. We predicted that the critical period for the effect of blindness on the area of V1 ends at a common developmental event-time across species. Our results support our prediction, and also show that the critical period for the effect of blindness on V1 surface area ends well before the visual cortex reaches its normal, mature size. Much of the research on the organization and function of visual cortex is presently carried out in mice. While a present advantage of mice is the possibility of using genetic tools, a disadvantage is the small size of their brain and visual cortex. In the third chapter, we use multiple anatomical tracers to explore the number, arrangement and internal topographic organization of extrastriate visual areas in the rabbit, whose brain is about 60 times larger than the mouse brain. Our results show that the visual cortical plan in rabbits closely resembles the plan in mice and rats, suggesting that the rodent plan may be more general, encompassing Lagomorphs and possibly other orders. Our study also underscores the usefulness of the rabbit as an alternative model to rats and mice for projects benefiting from a larger brain.

Download or read book Connectivity and Functional Organization in the Mammalian Visual Cortex written by Daniel Yue-Yun Ts'o and published by . This book was released on 1987 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 The Functional Organization of the Mammalian Visual Cortex is Revealed by Optical Imaging of Intrinsic Signals written by Estela V. O'Brien and published by . This book was released on 1996 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atlas of Morphology and Functional Anatomy of the Brain written by T. Scarabino and published by Springer Science & Business Media. This book was released on 2006-01-16 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent advances in neuroimaging techniques, particularly magnetic re- nance (MR), have greatly improved our knowledge of brain anatomy and related brain function. Morphological and functional investigations of the brain using high-definition MR have made detailed study of the brain possible and provided new data on anatomo-functional correlations. These studies have fuelled the interest in central nervous system imaging by clinicians (n- roradiologists, neurosurgeons, neurologists, neurophysiologists, and psych- trists) as well as biophysicists and bioengineers, who are at work on new and ever more sophisticated acquisition and processing techniques to continue to improve the potential of brain imaging methods. The possibility of obtaining high-definition MR images using a 3.0-T m- net prompted us, despite the broad existing literature, to conceive an atlas illustrating in a simple and effective way the anatomy of the brain and correl- ed functions. Following an introductory chapter by Prof. Pierre Rabischong, the atlas is divided into a morphological and a functional imaging section. The morphological atlas includes 3D surface images, axial, coronal, and sagittal scans acquired with high-definition T2 fast spin echo (FSE) sequences, and standard and inverted-contrast images. The MR scans are shown side by side with the corresponding anatomical brain sections, provided by Prof. Henri Duvernoy, for more effective comparison. The anatomical nomenclature adopted for both the MR and the anatomical images is listed in an jacket flap for easier consultation.

Download or read book Large scale Functional Models of Visual Cortex for Remote Sensing written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuroscience has revealed many properties of neurons and of the functional organization of visual cortex that are believed to be essential to human vision, but are missing in standard artificial neural networks. Equally important may be the sheer scale of visual cortex requiring (almost equal to)1 petaflop of computation. In a year, the retina delivers (almost equal to)1 petapixel to the brain, leading to massively large opportunities for learning at many levels of the cortical system. We describe work at Los Alamos National Laboratory (LANL) to develop large-scale functional models of visual cortex on LANL's Roadrunner petaflop supercomputer. An initial run of a simple region VI code achieved 1.144 petaflops during trials at the IBM facility in Poughkeepsie, NY (June 2008). Here, we present criteria for assessing when a set of learned local representations is 'complete' along with general criteria for assessing computer vision models based on their projected scaling behavior. Finally, we extend one class of biologically-inspired learning models to problems of remote sensing imagery.

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.

Download or read book From Photons to Photos written by Daniel E. Berman and published by . This book was released on 2015 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Immense strides in furthering our understanding of a variety of underlying mechanisms involved in visual perception are continuously being made, however numerous questions in the field remain unanswered. Detailed here are two studies aimed at elucidating the functional processes in which the human visual system integrates visual stimuli into cohesive representations of the world around us. First, using simulations and fMRI experiments we examined how retinotopic mapping paradigms can be optimized to most efficaciously and accurately measure the underlying functional and organizational properties of early to mid-level visual cortex in both healthy and clinical populations. We focused on quantitatively comparing two common retinotopic mapping designs in terms of measurable and achievable signal-to-noise ratios under various conditions such as exogenous noise and scanning time. While multifocal retinotopy can yield a higher signal-to-noise ratio in primary visual cortex, we find that the phase-encoded technique provides qualitatively better retinotopic maps despite having a less robust point-to-point correspondence of visual field location to visual cortex. Other implications of employing these methods are also discussed. Next, fMRI experiments aimed at uncovering the spatial frequency tuning profiles of higher-level, category selective areas of cortex such as the parahippocampal place area (PPA), retrospenial cortex (RSC), occipital place area (OPA), lateral occipital cortex (LOC) and the fusiform face area (FFA) were performed. These experiments utilized both frequency filtered scenes belonging to four different categories along with unstructured stimuli of various spatial frequencies. Results from univariate, multivariate and searchlight analyses are subsequently provided and elaborated on, with the general finding that the category selective areas mentioned above are sensitive to high spatial frequencies, especially when semantic information is present.