[PDF] Causal Evidence For Neural Oscillations In Cognition eBook

Author : Justin Riddle
Publisher :
Page : 76 pages
File Size : 50,6 MB
Release : 2018
Category :
ISBN :

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Since early recordings of the human brain, rhythmic electric fields have been observed emanating from regions involved in the specific information processing demands of which the human subject is engaged. Different oscillatory frequencies have been associated with different types of information processing. Neuroscience in the 21st century has seen a revival in research studying the neural basis of oscillatory activity that has deepened our understanding of the complex network level coordination of brain regions. However, causal evidence for the mechanistic role of neural oscillations is sparse, yet provides vital implications for the neural basis of cognition. The first experiment examines the specific role of beta (15-30 hertz) and gamma (30-50 hertz) frequency oscillations in top-down and bottom-up attention. By applying rhythmic transcranial magnetic stimulation (TMS), the purported cognitive contributions of beta and gamma oscillations are analyzed with respect to a visual search task that varies the level of top-down attention required for optimal performance. The second experiment examines the specific role of theta (3-8 hertz) and alpha (8-12 hertz) frequency neural oscillations in the reactivation and suppression of working memory representations. Rhythmic TMS in a retro-cued delayed match-to-sample task causally tested previously reported oscillatory neural signatures for their mechanistic contributions to working memory. The degree to which subjects engaged the regions targeted by TMS in functional magnetic resonance imaging (fMRI) predicted the frequency specific effect of rhythmic TMS. Simultaneous TMS and fMRI offers a unique opportunity to causally test the communication through coherence proposed with neural oscillations. By stimulating a single brain region in multiple frequency bands, the frequency-by-network specific spread of activation can be quantified. Towards this end, the third experiment develops the methodology of concurrent TMS-fMRI with a proof of principle experiment demonstrating the spread of TMS effects through a functional network. In sum, these projects test for the causal role of neural oscillations in cognition and pave the way for future research to study the network level organization of the brain via neural oscillations.

Author : Roger D. Traub
Publisher :
Page : 464 pages
File Size : 19,94 MB
Release : 2010
Category : Medical
ISBN : 0195342798

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This book first reviews the case that brain oscillations not only are important for cognition, as long suspected, but also play a part in the expression of signs and symptoms of neuropsychiatric disorders. The cellular mechanisms of many of the clinically relevant oscillations have been studied by the authors and their colleagues, using in vitro slice methods as well as detailed computer simulations. A surprising insight is that gap junctions between principal neurons play an absolutely critical role in so many types of oscillation in neuronal populations; oscillations are not just the result of properties of individual neurons and their synaptic connections. Furthermore, the way in which gap junctions produce oscillations in the cortex is novel, involving as it does global properties of networks, rather than just the time constants of membrane currents. This insight has implications for therapeutics as well as for our understanding of normal brain functions.

Author : Daniel S. Levine
Publisher : Psychology Press
Page : 454 pages
File Size : 44,91 MB
Release : 1999-09
Category : Psychology
ISBN : 1135691908

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Written for those interested in designing machines to perform intelligent functions & those interested in studying how these functions are performed by living organisms,this bk dicusses the mathematical structure & functional significance of neural oscil

Author : Erol Basar
Publisher : CRC Press
Page : 432 pages
File Size : 34,77 MB
Release : 2004-06-23
Category : Medical
ISBN : 1134394837

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Memory itself is inseparable from all other brain functions and involves distributed dynamic neural processes. A wealth of publications in neuroscience literature report that the concerted action of distributed multiple oscillatory processes (EEG oscillations) play a major role in brain functioning. The analysis of function-related brain oscillatio

Author : Roger Traub, MD
Publisher : Oxford University Press
Page : pages
File Size : 11,57 MB
Release : 2010-05-12
Category : Medical
ISBN : 019971150X

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This book first reviews the case that brain oscillations not only are important for cognition, as long suspected, but also play a part in the expression of signs and symptoms of neuropsychiatric disorders. The cellular mechanisms of many of the clinically relevant oscillations have been studied by the authors and their colleagues, using in vitro slice methods as well as detailed computer simulations. A surprising insight is that gap junctions between principal neurons play an absolutely critical role in so many types of oscillation in neuronal populations; oscillations are not just the result of properties of individual neurons and their synaptic connections. Furthermore, the way in which gap junctions produce oscillations in the cortex is novel, involving as it does global properties of networks, rather than just the time constants of membrane currents. This insight has implications for therapeutics as well as for our understanding of normal brain functions.

Author : Erol Başar
Publisher : Springer
Page : 0 pages
File Size : 49,57 MB
Release : 2011-09-22
Category : Science
ISBN : 9783642641701

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Neuroscience is ripe for a paradigm change as Freeman and Mountcastle describe. Brain Oscillations provide an important key to this change. In this book the functional importance of the brain's multiple oscillations is treated with an integrative scope. According to the author, neurophysiology and cognition demand integrative approaches similar to those of Galilei and Newton in physics and of Darwin in biology. Not only the human brain but also lower brains and ganglia of invertebrates are treated with electrophysical methods. Experiments on sensory registration, perception, movement, and cognitive processes related to attention, learning, and memory are described. A synopsis on brain functions leads to a new neuron assemblies doctrine, extending the concept of Sherrington, and new trends in this field. The book will appeal to scientists and graduate students.

Author : Joshua Hangman Siegle
Publisher :
Page : 170 pages
File Size : 22,50 MB
Release : 2014
Category :
ISBN :

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Neuroscientists hold widely divergent opinions on the behavioral relevance of oscillatory brain states. Some consider them to be a side effect of anatomical connectivity, with little or no role in guiding action. Others view them as a fundamental feature of the network states that underlie perception and cognition. In this thesis, I take a systematic approach to studying two of the most prominent types of oscillations,'gamma rhythms in the neocortex (30-80 Hz) and theta rhythms in the hippocampus (4-12 Hz). In both cases, I use light-gated ion channels to manipulate spike activity on a cycle-by-cycle basis in awake, behaving mice. By rhythmically stimulating fast-spiking interneurons in somatosensory cortex, I can emulate the activity patterns that define gamma oscillations under natural conditions. Emulating gamma enhances the detection of threshold-level vibrissae deflections, analogous to the behavioral effects of shifting attention. By triggering stimulation of fast-spiking interneurons in the hippocampus on peaks and troughs of endogenous rhythms, I can reduce spike activity at specific phases of theta. In the context of a spatial navigation task, I find that the ability of inhibition to enhance decision-making accuracy depends on both the theta phase and the task segment in which it occurs. Both of these experiments provide novel causal evidence for the behavioral impact of oscillations, which offers a much more compelling argument for their utility than traditional correlative measures. Finally, I present a new platform for extracellular electrophysiology. This platform, called Open Ephys, makes the closed-loop experiments that are ideal for studying oscillations accessible to a wider audience.

Author : Roumen Kirov
Publisher : Frontiers Media SA
Page : 102 pages
File Size : 10,26 MB
Release : 2017-04-28
Category :
ISBN : 2889451615

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Predictive coding (PC) is a neurocognitive concept, according to which the brain does not process the whole qualia of external information, but only residual mismatches occurring between incoming information and an individual, inner model of the world. At the time of issue initiation, I expected an essential focus on mismatch signals in the brain, especially those captured by neurophysiologic oscillations. This was because one most plausible approach to the PC concept is to identify and validate mismatch signals in the brain. Announcing the topic revealed a much deeper consideration of intelligible minds of researchers. It turned out that what was of fundamental interest was which brain mechanisms support the formation, maintenance and consolidation of the inner model determining PC. Is PC a dynamic construct continuously modulated by external environmental or internal mental information? The reader will be delighted to get acquainted with the current views and understanding of eminent scholars in the field. It will be challenging to discover the realm of sleep where both physiological, energy preserving and mental qualia principles build on the inner models to shape and transform the self. And where neurophysiologic oscillations may both transmit external information and translate inner models from state to state to preserve the self-continuity and compactness.

Author : Keiichi Kitajo
Publisher : Frontiers Media SA
Page : 247 pages
File Size : 20,98 MB
Release : 2015-05-29
Category : Neurosciences. Biological psychiatry. Neuropsychiatry
ISBN : 2889194795

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In this EBook, we highlight how newly emerging techniques for non-invasive manipulation of the human brain, combined with simultaneous recordings of neural activity, contribute to the understanding of brain functions and neural dynamics in humans. A growing body of evidence indicates that the neural dynamics (e.g., oscillations, synchrony) are important in mediating information processing and networking for various functions in the human brain. Most of previous studies on human brain dynamics, however, show correlative relationships between brain functions and patterns of neural dynamics measured by imaging methods such as electroencephalography (EEG), magnetoencephalography (MEG), near-infrared spectroscopy (NIRS), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). In contrast, manipulative approaches by non-invasive brain stimulation (NIBS) have been developed and extensively used. These approaches include transcranial magnetic stimulation (TMS) and transcranial electric stimulation (tES) such as transcranial direct current stimulation (tDCS), alternating current stimulation (tACS), and random noise stimulation (tRNS), which can directly manipulate neural dynamics in the intact human brain. Although the neural-correlate approach is a strong tool, we think that manipulative approaches have far greater potential to show causal roles of neural dynamics in human brain functions. There have been technical challenges with using manipulative methods together with imaging methods. However, thanks to recent technical developments, it has become possible to use combined methods such as TMS–EEG coregistration. We can now directly measure and manipulate neural dynamics and analyze functional consequences to show causal roles of neural dynamics in various brain functions. Moreover, these combined methods can probe brain excitability, plasticity and cortical networking associated with information processing in the intact human brain. The contributors to this EBook have succeeded in showcasing cutting-edge studies and demonstrate the huge impact of their approaches on many areas in human neuroscience and clinical applications.