Interpretation of Mammalian Brain Rhythms of Sensorimotor Processing

Interpretation of Mammalian Brain Rhythms of Sensorimotor Processing

Author: Diane J. Whitmer

Publisher:

Published: 2008

Total Pages: 187

ISBN-13:

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A fundamental goal of neuroscience is to relate neural signals with external sensory stimuli and with complex behaviors such as movement. In many systems and brain regions, brain oscillations correlate with movement. The body of work presented here examines the role of oscillations in both sensory representation and motor output, spanning multiple scales of measurement from local field potential recordings to the large-scale electrical activity of the whole human brain. The vibrissa system of rats is an active sensory motor system where the whiskers are actively moved to explore the environment. The work described in Chapter II uses a behavioral paradigm to test coding strategies within the rat vibrissa system. We ask whether rats can discriminate the position of objects in the plane within which the whiskers move and whether discrimination can be accomplished with a single vibrissa. We report that rats can locate the position of objects in space relative to its body position with a single whisker, suggesting a neural code based on timing of the whisking cycle. Chapter III examines a salient, widespread oscillation associated with movements in rats (the theta rhythm), to determine whether this signal might drive whisking behavior. We find that hippocampal theta and the whisking rhythm are not coherent although they are oscillatory signals within the same spectral band. In humans, invasive brain measurements are possible in the cases of focal refractory epilepsy patients who are undergoing neurosurgical evaluation. Chapter IV uses intracranial measurements from epilepsy patients who performed a visually-cued finger movement task, to understand the electrical signals that enable a complex sensory motor action. We analyze signals spectrally, examining oscillations with a linear systems approach, specifically using independent component analysis (ICA) to interpret the signals. We find that ICA can separate pathological brain signals from motor signals and decompose intracranial signals into its underlying sources. Together, these results demonstrate that oscillations of peripheral sensors can encode the representation of spatial information, that neural rhythms in overlapping frequency bands are not necessarily entrained, and that ICA is a useful tool for ummixing motor and other signals in the human brain.


Rhythms of the Brain

Rhythms of the Brain

Author: G. Buzsáki

Publisher: Oxford University Press

Published: 2011

Total Pages: 465

ISBN-13: 0199828237

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Studies of mechanisms in the brain that allow complicated things to happen in a coordinated fashion have produced some of the most spectacular discoveries in neuroscience. This book provides eloquent support for the idea that spontaneous neuron activity, far from being mere noise, is actually the source of our cognitive abilities. It takes a fresh look at the coevolution of structure and function in the mammalian brain, illustrating how self-emerged oscillatory timing is the brain's fundamental organizer of neuronal information. The small-world-like connectivity of the cerebral cortex allows for global computation on multiple spatial and temporal scales. The perpetual interactions among the multiple network oscillators keep cortical systems in a highly sensitive "metastable" state and provide energy-efficient synchronizing mechanisms via weak links. In a sequence of "cycles," György Buzsáki guides the reader from the physics of oscillations through neuronal assembly organization to complex cognitive processing and memory storage. His clear, fluid writing-accessible to any reader with some scientific knowledge-is supplemented by extensive footnotes and references that make it just as gratifying and instructive a read for the specialist. The coherent view of a single author who has been at the forefront of research in this exciting field, this volume is essential reading for anyone interested in our rapidly evolving understanding of the brain.


Discovering the Brain

Discovering the Brain

Author: National Academy of Sciences

Publisher: National Academies Press

Published: 1992-01-01

Total Pages: 195

ISBN-13: 0309045290

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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."


The Evolution of Rhythm Cognition: Timing in Music and Speech

The Evolution of Rhythm Cognition: Timing in Music and Speech

Author: Andrea Ravignani

Publisher: Frontiers Media SA

Published: 2018-07-24

Total Pages: 391

ISBN-13: 2889455009

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Human speech and music share a number of similarities and differences. One of the closest similarities is their temporal nature as both (i) develop over time, (ii) form sequences of temporal intervals, possibly differing in duration and acoustical marking by different spectral properties, which are perceived as a rhythm, and (iii) generate metrical expectations. Human brains are particularly efficient in perceiving, producing, and processing fine rhythmic information in music and speech. However a number of critical questions remain to be answered: Where does this human sensitivity for rhythm arise? How did rhythm cognition develop in human evolution? How did environmental rhythms affect the evolution of brain rhythms? Which rhythm-specific neural circuits are shared between speech and music, or even with other domains? Evolutionary processes’ long time scales often prevent direct observation: understanding the psychology of rhythm and its evolution requires a close-fitting integration of different perspectives. First, empirical observations of music and speech in the field are contrasted and generate testable hypotheses. Experiments exploring linguistic and musical rhythm are performed across sensory modalities, ages, and animal species to address questions about domain-specificity, development, and an evolutionary path of rhythm. Finally, experimental insights are integrated via synthetic modeling, generating testable predictions about brain oscillations underlying rhythm cognition and its evolution. Our understanding of the cognitive, neurobiological, and evolutionary bases of rhythm is rapidly increasing. However, researchers in different fields often work on parallel, potentially converging strands with little mutual awareness. This research topic builds a bridge across several disciplines, focusing on the cognitive neuroscience of rhythm as an evolutionary process. It includes contributions encompassing, although not limited to: (1) developmental and comparative studies of rhythm (e.g. critical acquisition periods, innateness); (2) evidence of rhythmic behavior in other species, both spontaneous and in controlled experiments; (3) comparisons of rhythm processing in music and speech (e.g. behavioral experiments, systems neuroscience perspectives on music-speech networks); (4) evidence on rhythm processing across modalities and domains; (5) studies on rhythm in interaction and context (social, affective, etc.); (6) mathematical and computational (e.g. connectionist, symbolic) models of “rhythmicity” as an evolved behavior.


Dynamics of Sensory and Cognitive Processing by the Brain

Dynamics of Sensory and Cognitive Processing by the Brain

Author: Theodore Melnechuk

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 408

ISBN-13: 3642715311

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In neurophysiology, the emphasis has been on single-unit studies for a quarter century, since the sensory work by Lettwin and coworkers and by Hubel and Wiesel, the cen tral work by Mountcastle, the motor work by the late Evarts, and so on. In recent years, however, field potentials - and a more global approach general ly - have been receiving renewed and increasing attention. This is a result of new findings made possible by technical and conceptual advances and by the confirma tion and augmentation of earlier findings that were widely ignored for being contro versial or inexplicable. To survey the state of this active field, a conference was held in West Berlin in August 1985 that attempted to cover all of the new approaches to the study of brain function. The approaches and emphases were very varied: basic and applied, electric and magnetic, EEG and EP/ERP, connectionistic and field, global and local fields, surface and multielectrode, low frequencies and high frequencies, linear and non linear. The conference comprised sessions of invited lectures, a panel session of seven speakers on "How brains may work," and a concluding survey of relevant methodologies. The conference showed that the combination of concepts, methods, and results could open up new important vistas in brain research. Included here are the proceedings of the conference, updated and revised by the authors. Several attendees who did not present papers at the conference later ac cepted my invitation to write chapters for the book.


Understanding the Role of Time-Dimension in the Brain Information Processing

Understanding the Role of Time-Dimension in the Brain Information Processing

Author: Daya Shankar Gupta

Publisher: Frontiers Media SA

Published: 2017-04-13

Total Pages: 139

ISBN-13: 2889451496

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Optimized interaction of the brain with environment requires the four-dimensional representation of space-time in the neuronal circuits. Information processing is an important part of this interaction, which is critically dependent on time-dimension. Information processing has played an important role in the evolution of mammals, and has reached a level of critical importance in the lives of primates, particularly the humans. The entanglement of time-dimension with information processing in the brain is not clearly understood at present. Time-dimension in physical world – the environment of an organism – can be represented by the interval of a pendulum swing (the cover page depicts temporal unit with the help of a swinging pendulum). Temporal units in neural processes are represented by regular activities of pacemaker neurons, tonic regular activities of proprioceptors and periodic fluctuations in the excitability of neurons underlying brain oscillations. Moreover, temporal units may be representationally associated with time-bins containing bits of information (see the Editorial), which may be studied to understand the entanglement of time-dimension with neural information processing. The optimized interaction of the brain with environment requires the calibration of neural temporal units. Neural temporal units are calibrated as a result of feedback processes occurring during the interaction of an organism with environment. Understanding the role of time-dimension in the brain information processing requires a multidisciplinary approach, which would include psychophysics, single cell studies and brain recordings. Although this Special Issue has helped us move forward on some fronts, including theoretical understanding of calibration of time-information in neural circuits, and the role of brain oscillations in timing functions and integration of asynchronous sensory information, further advancements are needed by developing correct computational tools to resolve the relationship between dynamic, hierarchical neural oscillatory structures that form during the brain’s interaction with environment.


Anatomy and Physiology

Anatomy and Physiology

Author: Amy-Jane Beer

Publisher: Marshall Cavendish

Published: 2010

Total Pages: 200

ISBN-13: 9780761499541

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This reference volume takes a look at nine biological systems and their foundations in cell biology and genetics.