Author: Svetlana Levitan Publisher: ISBN: Category : Brain mapping Languages : en Pages : 274
Book Description
Recent experimental work in neurobiology has defined asymmetries and lateralization in the topographic maps found in mirror-image regions of the sensorimotor cerebral cortex. However, the mechanisms underlying these asymmetries are currently not established, and in some cases are quite controversial. In order to explore some possible causes of map asymmetry and lateralization, several neural network models of cortical map lateralization and asymmetries based on self-organizing maps are created and studied both computationally and theoretically. Activation levels of the elements in the models are governed by large systems of highly nonlinear ordinary differential equations (ODEs), where coefficients change with time and their changes depend on the activation levels. Special metrics for objective evaluation of simulation results (represented as paired receptive field maps) are introduced and analysed. The behavior of the models is studied when their parameters are varied systematically and also when simulated lesions are introduced into one of the hemispheric regions. Some very sharp transitions and other interesting phenomena have been found computationally. Many of these computationally observed phenomena are explained by theoretical analysis of total hemispheric activation in a simplified model. The connection between a bifurcation point of the system of ODEs and the sharp transition in the model's computational behavior is established. More general understanding of topographic map formation and changes under various conditions is achieved by analysis of activation patterns (i.e., omega-limit sets of the above system of ODEs). This is the first mathematical model to demonstrate spontaneous map lateralization and asymmetries, and it suggests that such models may be generally useful in better understanding the mechanisms of cerebral lateralization. The mathematical analysis of the models leads to a better understanding of the mechanisms of self-organization in the topographic maps based on competitive distribution of activation and competitive learning.
Author: Stanley Glick Publisher: Elsevier ISBN: 0323156916 Category : Nature Languages : en Pages : 303
Book Description
Cerebral Lateralization in Nonhuman Species explores brain asymmetries in animals and the extent to which such asymmetries relate, in an evolutionary and clinical sense, to the pervasive asymmetries that characterize the human brain. Topics covered include cerebral lateralization in birds, rats, and nonhuman primates; the inheritance of direction and degree of asymmetry in the brain; the morphology of rat forebrain; and variation in the pattern of behavioral and brain asymmetries due to sex differences. Comprised of 11 chapters, this book opens with a historical overview of research into the cerebral lateralization of structures and functions in nonhuman species. The discussion then turns to lateralization of vocal control in songbirds and lateralization of several behaviors in domestic chicks. The inheritance of direction and degree of asymmetry is also considered, along with the morphology of rat forebrains. The following chapters focus on asymmetries in anatomy and pathology in the rodent brain; the link between brain lateralization and behavioral functions; and how early experiences can induce laterality. The final chapter analyzes the implications of brain asymmetries for evolution, genetics, and clinical syndromes. This monograph will be a useful resource for students, neuroscientists, clinicians, and other practitioners in fields ranging from psychobiology and psychology to anatomical sciences, neurobiology, neurochemistry, and genetics.
Author: H.A. Mastebroek Publisher: Springer Science & Business Media ISBN: 9401006741 Category : Computers Languages : en Pages : 264
Book Description
The expression 'Neural Networks' refers traditionally to a class of mathematical algorithms that obtain their proper performance while they 'learn' from examples or from experience. As a consequence, they are suitable for performing straightforward and relatively simple tasks like classification, pattern recognition and prediction, as well as more sophisticated tasks like the processing of temporal sequences and the context dependent processing of complex problems. Also, a wide variety of control tasks can be executed by them, and the suggestion is relatively obvious that neural networks perform adequately in such cases because they are thought to mimic the biological nervous system which is also devoted to such tasks. As we shall see, this suggestion is false but does not do any harm as long as it is only the final performance of the algorithm which counts. Neural networks are also used in the modelling of the functioning of (sub systems in) the biological nervous system. It will be clear that in such cases it is certainly not irrelevant how similar their algorithm is to what is precisely going on in the nervous system. Standard artificial neural networks are constructed from 'units' (roughly similar to neurons) that transmit their 'activity' (similar to membrane potentials or to mean firing rates) to other units via 'weight factors' (similar to synaptic coupling efficacies).
Author: Annakarina Mundorf Publisher: Routledge ISBN: 1000414221 Category : Psychology Languages : en Pages : 167
Book Description
The Clinical Neuroscience of Lateralization gives the first comprehensive transdiagnostic overview of the evidence for changes in hemispheric asymmetries in different psychiatric and neurodevelopmental disorders. Taking a multidisciplinary perspective informed by both basic science and clinical studies, the authors integrate recent breakthroughs on hemispheric asymmetries in psychology, neuroscience, genetics and comparative research. They give a general introduction to hemispheric asymmetries and the techniques used to assess them, and review the evidence for changes in hemispheric asymmetries in different psychiatric and neurodevelopmental disorders. The book also discusses neurological disorders like Parkinson’s disease and multiple sclerosis and highlights the importance of open science in clinical laterality research. Offering a fresh perspective on a longstanding issue in clinical neuroscience, this book will be of great interest for academics, researchers, and students in the fields of clinical and developmental neuroscience, biopsychology and neuropsychology.
Author: Joseph B. Hellige Publisher: Harvard University Press ISBN: 9780674005594 Category : Brain Languages : en Pages : 418
Book Description
Is "right-brain" thought essentially creative, and "left-brain" strictly logical? Joseph B. Hellige argues that this view is far too simplistic. Surveying extensive data in the field of cognitive science, he disentangles scientific facts from popular assumptions about the brain's two hemispheres. In Hemispheric Asymmetry, Hellige explains that the "right brain" and "left brain" are actually components of a much larger cognitive system encompassing cortical and subcortical structures, all of which interact to produce unity of thought and action. He further explores questions of whether hemispheric asymmetry is unique to humans, and how it might have evolved. This book is a valuable overview of hemispheric asymmetry and its evolutionary precedents.
Author: Andrea Bernasconi Publisher: Cambridge University Press ISBN: 1107108357 Category : Medical Languages : en Pages : 263
Book Description
Assembles world-class expertise on clinical and molecular imaging-derived biomarkers, presenting neuroimaging in epilepsy in a broad neuroscientific context.
Author: Svetlana Levitan
Author: Stanley Glick
Author: Anke Bouma
Author: 
Author: H.A. Mastebroek
Author: Annakarina Mundorf
Author: Joseph B. Hellige
Author: Kenneth Hugdahl
Author: Constantin Freiherr von Economo
Author: Andrea Bernasconi