Open Access Medical Books

VISUAL CORTEX – CURRENT STATUS AND PERSPECTIVES

VISUAL CORTEX
Edited by Stéphane Molotchnikoff and Jean Rouat .
Open Access .


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.
For a long time, university students have been taught that after the critical period following birth the brain remains relatively unchanged except for a gradual neuronal loss accompanying aging. As recent research demonstrates this latter view was a false perception of brain organization because indeed the adult brain is incredibly plastic.
Thus it should not come as a surprise that this book contains several chapters dealing with adult brain modifications. Furthermore, thanks to recent advances in histological techniques, cellular membranes of neurons exhibit an extraordinary complexity, even though they constitute the structural unit membrane of the neuron. Bueno-Lopez and Chara et al. review subtypes of cerebral cortical principal cells and provide a detailed description of cellular partitions such as axon initial segments. Brewer and Barton expand our current understanding of the visual field map in human visual cortex organization and reciprocal connections as they relate to specific functions. Yet mapping comes with intrinsic problems, e.g., the coupling or uncoupling between neurovasculature and neurometabolic requirements. Ling and Gao et al., describe this challenge, adding an interesting historical note.
Plasticity in the adult brain constitutes the key theme of the majority of chapters since this particular field has seen remarkable development at all functional levels. Maya- Ventencourt and Caleo compellingly discuss processes of sensory deprivation in the visual system at intracellular signal transduction pathways which regulate changes of chromatin structure and gene expression patterns supporting these plastic phenomena. For many years plasticity was studied by deprivation, that is, eliminating or limiting visual inputs. Fortunately, recent experiments reversed this approach by introducing a novel experimental design that enriches the visual environment or by imposing particular stimuli. Sale and Berardi et al.'s chapter aims to review recent studies, mostly focusing on the effects of enriching the visual environment in promoting visual system development and in reopening neural plasticity windows in the adult brain. Special emphasis is given to excitation / inhibition balance, and to promoting functional recovery from pathological states of severe brain disability.
Along this line Bachatene and Bharmauria et al., compellingly describe the change of functional connections between involved neurons following adaptation-induced plasticity. After forcefully adapting the same neurons to a desired stimulus feature, and using the cross correlogram approach, functional connections were established before and after adaptation between the same neurons recorded simultaneously in the primary visual cortex. The data show the network between them changed, reflecting on the ability of visual cortex for plastic modifications of its relationships between neurons following adaptation. Using brain optical imaging Tanaka is of the same opinion that the short-term single-orientation exposure can dramatically alter preferred orientations until postnatal 6 weeks, which is against the current consensus and reveals further complexity in orientation plasticity in cases where animals are exposed to a single orientation for a long time. Gerrikagoitial and Rienda et al. stress convincingly the importance of inhibitory factors regulating connections and sprouting capacity within the cortico-collicular network during plasticity processes.
Yet vision as it is processed in visual cortex is not by all means an end in itself as it initiates image perception that steers our behaviour. This book offers several chapters dealing with the topic.
Contextual influences should not be underestimated when investigating neuronal responses to visual stimuli. Arall and Romeo et al. describe findings showing that evoked responses in the primary visual cortex are modulated by surrounding stimuli.
The role of extra-classical receptive field is highlighted in the figure-ground organization of an image. Peyrin and Musel aim to clarify the different attributes of  the occipital cortex during scene perception. This suggests that the occipital cortex might serve as an“active blackboard”integrating the rapid analysis of low spatial frequency (LSF) carried out by higher order cortical areas and sent back via feedback connections to occipital areas to influence the subsequent analysis of high spatial frequencies (HSF) features. Concomitantly, the right occipital cortex is predominantly involved in the categorization LSF processing, while the left occipital cortex is chiefly involved in the categorization of HSF scenes. Buckthought and Mendola explain the methodological issues involved in perception investigations, showing that perceptual processing modalities can be conceptualized as a series of visual perceptual processing stages in occipital areas, as well as higher-level cognitive functions in parietal and frontal areas, involving stimulus selection, decision making, motor planning, memory, attention and conscious awareness. Stockdale and Thompson review comprehensively  key aspects of visual motion perception with a particular emphasis on the cortical areas thought to be involved and the ability of the visual cortex to bind multiple features together into a coherent, stable visual percept. In addition, the effects of lesions and abnormal development affecting the cortical areas responsible for motion perception are described. Cameron and Binsted examine the relationship between vision and action, and survey evidence that regions of posterior parietal cortex are designed for directly transforming vision into action; interestingly, studies from patients and non-patients suggest that action processing can access visual information that perception does not. Smith and Masse et al. pose a challenging question: how  does visual perception arise from the activity of neurons in visual cortex? The authors introduce the important concept of‘behavioral sensitivity’neurons to answer this question that requires an understanding of how a visual cortical neuron's activity becomes correlated with the visually guided behavior of a subject.
The book ends with topics that are likely to blossom in the near future, i.e., modeling the complexity of brain functions. Castellanos-Sanchez and Hernandez et al. introduce the reader to bio-inspired models. Yang considers the brain as a statistical machine.
The argument rests on the proposition that the statistics of the natural visual environment must be incorporated into the visual circuitry by successful behavior in the world over evolutionary and developmental time. Indeed, there is an almost infinite number of ways to model any given system, and this is particularly true if we are interested in something as complex as the human brain, including the visual cortex. By contrast Ladurantaye and Rouat et al. attempt in depth to regroup the different types of models into meaningful categories, to give the reader a fair overview of what is possible to achieve in terms of modeling biological vision. Each section of the chapter focuses on one of those categories and includes different implementation  methods (i.e., specific models).
In closing it is our agreeable duty to express our gratitude to many anonymous reviewers who diligently revised the chapters. Finally, Mrs. Bakic is unreservedly thanked for her help during the tedious editing processes.



Prof. Dr. Stephane Molotchnikoff

Department of Biological Sciences, Faculty of Arts and Sciences, University of
Montreal,
Canada
Prof. Jean Rouat
Department of Electrical and Computer Engineering, Faculty of Engineering,
University of Sherbrooke,

Canada
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CONTENTS OF THE TEXTBOOK :




 1 Projections, Partaken Circuits and Axon Initial Segments of Cortical Principal Neurons.  
José L. Bueno-López, Juan C. Chara, Juan L. Mendizabal-Zubiaga and Concepción Reblet


 2 Visual Field Map Organization in Human Visual Cortex 29 Alyssa A. Brewer and Brian Barton

 3 On the Specific Role of the Occipital Cortex in Scene Perception 61 Carole Peyrin and Benoit Musel

 4 Neural Mechanisms for Binocular Depth, Rivalry and Multistability 83 Athena Buckthought and Janine D. Mendola

 5 Visual Motion: From Cortex to Percept 111 Craig Aaen-Stockdale and Benjamin Thompson

 6 Visual Processing in the Action-Oriented Brain 139 Brendan D. Cameron and Gordon Binsted

 7 Linking Neural Activity to Visual Perception: Separating Sensory and Attentional Contributions 161 Jackson E.T. Smith, Nicolas Y. Masse, Chang'an A. Zhan and Erik P. Cook

 8 Bio-Inspired Architecture for Clustering into Natural and Non-Natural Facial Expressions 185 Claudio Castellanos Sánchez, Manuel Hernández Hernández and Pedro Luis Sánchez Orellana

 9 Vision as a Fundamentally Statistical Machine 201 Zhiyong Yang

 10 Models of Information Processing in the Visual Cortex 227 Vincent de Ladurantaye, Jean Rouat and Jacques Vanden-Abeele

 11 Neurovascular and Neurometabolic Uncoupling in the Visual Cortex 247 Ai-Ling Lin, Jia-Hong Gao and Peter T. Fox

 12 Experience Mediated Development of the Visual Cortex Vascularization 265 Enrike G. Argandoña, Harkaitz Bengoetxea, Naiara Ortuzar, Susana Bulnes, Irantzu Rico-Barrio and José Vicente Lafuente

 13 Insights into Visual Cortex Plasticity: Interaction Between Genes and Sensory Experience 279 José Fernando Maya-Vetencourt and Matteo Caleo

 14 Environmental Influences on Visual Cortex Development and Plasticity 295 Alessandro Sale, Nicoletta Berardi and Lamberto Maffei

 15 Adaptation and Neuronal Network in Visual Cortex 323 Lyes Bachatene, Vishal Bharmauria and Stéphane Molotchnikoff

 16 New Pictures of the Structure and Plasticity of Orientation Columns in the Visual Cortex  341 Shigeru Tanaka

 17 The Experimental Manipulation of Visual Cortex Efferents 367 I. Gerrikagoitia, B. Rienda and L. Martínez-Millán

 18 Role of Feedforward and Feedback Projections in Figure-Ground Responses 389 Marina Arall, August Romeo and Hans Supèr .



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