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Oscillatory "Temporal Sampling" and Developmental Dyslexia: Towards an Over-Arching Theoretical Framework

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194391 Year: Pages: 155 DOI: 10.3389/978-2-88919-439-1 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2016-01-19 14:05:46
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Children with developmental dyslexia fail to acquire efficient reading and spelling skills despite adequate tuition and an absence of overt sensory and/ or neural deficits. Learning to read and spell requires linguistic skills, auditory skills and visual skills. Oscillatory 'temporal sampling' theory links the development of sensory and linguistic processes. The auditory system 'samples' acoustic information at different temporal rates, which for speech processing suggests that temporal information encoded by delta, theta and gamma oscillations is bound together in the final speech percept. Temporal sampling theory proposed a possible deficit in dyslexia in auditory sampling of the speech signal at syllable-relevant rates (< 10 Hz, delta and theta). This would hypothetically affect prosodic development prior to reading and syllable-based parsing, which would affect efficient linguistic skills and consequently reading development across languages. The visual system also samples information in the visuo-spatial field. In theory atypical visual oscillatory sampling could therefore be related to some of the visual features of developmental dyslexia. In this special issue, we bring together visual and auditory sensory processing studies around the general theme of oscillatory temporal sampling. Contributors were encouraged to discuss their findings within a temporal sampling perspective. The resulting studies cover a wide range of sensory processes, with findings both supporting and contradicting the theory. It is also important to note that studies covered a wide range of languages, and that the behavioural manifestations of a sampling impairment may differ both with language and over the course of development. Nevertheless, it is encouraging to see such diverse findings considered within a single theoretical framework, even if at the same time, it is apparent that an over-arching theoretical framework encompassing both visual and auditory deficits in dyslexia is yet to be achieved.

Influence of Emitter Surface Roughness and Emission Inhomogeneity on Efficiency and Stability of High Power Fusion Gyrotrons

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Book Series: Karlsruher Forschungsberichte aus dem Institut für Hochleistungsimpuls- und Mikrowellentechnik ISSN: 21922764 ISBN: 9783731505785 Year: Volume: 9 Pages: XV, 197 p. DOI: 10.5445/KSP/1000058566 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:01:59
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The increasing demand for powerful, reliable, and efficient gyrotron oscillators for Electron Cyclotron Resonance Heating (ECRH) in fusion plasma experiments requires a close look at the various factors in gyrotrons that determine gyrotron performance. In this frame, the influence of emitter surface roughness, emission inhomogeneity, and secondary electron generation on gyrotron operation is presented, with focus on Low Frequency Oscillations (LFOs) and Electron Beam Halo (EBH) generation.

Sleep Spindles: Breaking the Methodological Wall

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451166 Year: Pages: 228 DOI: 10.3389/978-2-88945-116-6 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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In the last decade, sleep spindles have attracted steadily increasing attention. This interest is motivated by the many intriguing relationships between spindles and various diseases (e.g., schizophrenia, Parkinson, Alzheimer, autism, mental retardation), recovery processes (e.g., post brain stroke), and cognitive faculties (e.g., memory consolidation, intelligence, dream recall, sleep preservation). Nonetheless, a methodological wall has impeded the study of sleep spindles. Their investigation rests heavily on our ability to reliably and consistently identify spindle patterns from background EEG activity, a task involving many obstacles, including: a fuzzy definition of spindles, low inter-expert agreement on their scoring, lack of consensus on standard techniques for their automated detection, low reproducibility of observed characteristics and correlates, unavailability of large, standardized, high-quality databases, and inconsistencies in the methods used to evaluate the performance of automated detectors. The primary aims of this research topic were to bring together world-class researchers on a project designed to facilitate exchanges on methodological difficulties encountered in assessing sleep spindles and to promote standardized spindle-related resources. In preparing their contributions, authors were encouraged to use existing – or to propose new – publicly available resources for assessing sleep spindles. To allow fair and accurate comparison of reported results, the authors were also encouraged to validate their tools on a common benchmark. A database containing expert spindle scoring (i.e., the Montreal Archive of Sleep Studies) was made publicly available for that purpose.

The Cognitive Thalamus

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195411 Year: Pages: 125 DOI: 10.3389/978-2-88919-541-1 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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Cognitive processing is commonly conceptualized as being restricted to the cerebral cortex. Accordingly, electrophysiology, neuroimaging and lesion studies involving human and animal subjects have almost exclusively focused on defining roles for cerebral cortical areas in cognition. Roles for the thalamus in cognition have been largely ignored despite the fact that the extensive connectivity between the thalamus and cerebral cortex gives rise to a closely coupled thalamo-cortical system. However, in recent years, growing interest in the thalamus as much more than a passive sensory structure, as well as methodological advances such as high-resolution functional magnetic resonance imaging of the thalamus and improved electrode targeting to subregions of thalamic nuclei using electrical stimulation and diffusion tensor imaging, have fostered research into thalamic contributions to cognition.Evidence suggests that behavioral context modulates processing in primary sensory, or first-order, thalamic nuclei (for example, the lateral geniculate and ventral posterior nuclei), allowing attentional filtering of incoming sensory information at an early stage of brain processing. Behavioral context appears to more strongly influence higher-order thalamic nuclei (for example, the pulvinar and mediodorsal nucleus), which receive major input from the cortex rather than the sensory periphery. Such higher-order thalamic nuclei have been shown to regulate information transmission in frontal and higher-order sensory cortex according to cognitive demands. This Research Topic aims to bring together neuroscientists who study different parts of the thalamus, particularly thalamic nuclei other than the primary sensory relays, and highlight the thalamic contributions to attention, memory, reward processing, decision-making, and language. By doing so, an emphasis is also placed on neural mechanisms common to many, if not all, of these cognitive operations, such as thalamo-cortical interactions and modulatory influences from sources in the brainstem and basal ganglia. The overall view that emerges is that the thalamus is a vital node in brain networks supporting cognition.

Beyond the simple contrastive analysis: Appropriate experimental approaches for unraveling the neural basis of conscious experience

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195473 Year: Pages: 129 DOI: 10.3389/978-2-88919-547-3 Language: English
Publisher: Frontiers Media SA
Subject: Psychology --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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Contrasting conditions with and without conscious experience has served consciousness research well. However, research based on this simple contrast has led to controversies about the neural basis of conscious experience. One key reason for these ongoing debates seems to be that the simple contrast between conditions with and without consciousness is not specific for unraveling the neural basis of conscious experience, but rather also leads to other processes that precede or follow it. Acknowledging this methodological problem implies that some of the previous research findings about the neural underpinnings of conscious experience are actually reflecting the prerequisites and consequences rather than the direct correlates of conscious perception. Thus, it is required to re-evaluate the previous results to find out which of them are telling us anything about the neural basis of consciousness. But first and foremost, to overcome this methodological problem we need new experimental paradigms that go beyond the simple contrastive analysis or find the ways how some older but well forgotten paradigms may foster a new look at this emerging problem. Accordingly, this research topic is looking for empirical and theoretical contributions that: 1) envision new and suitable experimental approaches to study consciousness that are free from the limitations of the simple contrastive analysis; 2) provide empirical data that help to separate the neural correlates of conscious experience from the prerequisites and consequences of it; 3) help to re-assess previous research findings about the neural correlates of conscious perception in the light of the methodological problems with the traditional contrastive analysis. We hope that the theoretical insights and experimental approaches collected within this Research Topic help us to gain a more refined understanding of the neural basis of conscious experience.

Neural Masses and Fields: Modelling the Dynamics of Brain Activity

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194278 Year: Pages: 237 DOI: 10.3389/978-2-88919-427-8 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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Biophysical modelling of brain activity has a long and illustrious history and has recently profited from technological advances that furnish neuroimaging data at an unprecedented spatiotemporal resolution. Neuronal modelling is a very active area of research, with applications ranging from the characterization of neurobiological and cognitive processes, to constructing artificial brains in silico and building brain-machine interface and neuroprosthetic devices. Biophysical modelling has always benefited from interdisciplinary interactions between different and seemingly distant fields; ranging from mathematics and engineering to linguistics and psychology. This Research Topic aims to promote such interactions by promoting papers that contribute to a deeper understanding of neural activity as measured by fMRI or electrophysiology.In general, mean field models of neural activity can be divided into two classes: neural mass and neural field models. The main difference between these classes is that field models prescribe how a quantity characterizing neural activity (such as average depolarization of a neural population) evolves over both space and time as opposed to mass models, which characterize activity over time only; by assuming that all neurons in a population are located at (approximately) the same point. This Research Topic focuses on both classes of models and considers several aspects and their relative merits that: span from synapses to the whole brain; comparisons of their predictions with EEG and MEG spectra of spontaneous brain activity; evoked responses, seizures, and fitting data - to infer brain states and map physiological parameters.

Components of the language-ready brain

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198931 Year: Pages: 132 DOI: 10.3389/978-2-88919-893-1 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Psychology
Added to DOAB on : 2016-01-19 14:05:46
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This volume highlights new avenues of research in the language sciences, and particularly, in the neurobiology of language. The term “language-ready brain” stresses, on the one hand, the importance of a brain-based description of our species’ linguistic capacity, and, on the other, the need to appreciate the crucial role culture plays in shaping the linguistic systems children acquire and adults use. For this reason, the focus is not put on language per se, but on our learning biases and cognitive pre-dispositions toward language. Both brain and culture are considered at two crucial levels of inquiry: phylogeny and ontogeny. In a fast-growing field like the language sciences and specifically, language evolution studies, this book has tried to capture several of the most exciting topics explored currently, sowing seeds for future investigations.

Emotional Modulation of the Synapse

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196067 Year: Pages: 135 DOI: 10.3389/978-2-88919-606-7 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2016-08-16 10:34:25
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Highly emotional events tend to be well remembered. The adaptive value in this is clear – those events that have a bearing on survival should be stored for future use as long-term memories whereas memories of inconsequential events would not as likely contribute to future survival. Enduring changes in the structure and function of synapses, neural circuitry, and ultimately behavior, can be modulated by highly aversive or rewarding experiences. In the last decade, the convergence of cellular, molecular, and systems neuroscience has produced new insights into the biological mechanisms that determine whether a memory will be stored for the long-term or lost forever. This Research Topic brings together leading experts, who work at multiple levels of analysis, to reveal recent discoveries and concepts regarding the synaptic mechanisms of consolidation and extinction of emotionally arousing memories.

Distributed Networks: New Outlooks on Cerebellar Function

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196265 Year: Pages: 211 DOI: 10.3389/978-2-88919-626-5 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2016-08-16 10:34:25
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Accumulating evidence suggests that the cerebellum subserves functions beyond the sensorimotor realm. This possibility has received considerable attention during the past quarter century, with recent findings revealing putative cerebellar roles in cognition, emotion and spatial navigation. These functions are potentially underpinned by the behaviour-dependent formation of functional networks in which the cerebellum forms one node of distributed circuits spanning thalamic, limbic and neocortical regions. However, these views are not universally accepted. Therefore, the over-arching aim of this Research Topic was to provide a forum through which the debate on the role of cerebellar interactions with motor and "non-motor" structures can be pursued in a rigorous manner. In particular, we aimed to bring together findings from the clinical, animal, theoretical and neuroimaging fields.

Brain Oscillations and Predictive Coding: What We Know and What We Should Learn

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451616 Year: Pages: 100 DOI: 10.3389/978-2-88945-161-6 Language: English
Publisher: Frontiers Media SA
Subject: Psychology --- Science (General)
Added to DOAB on : 2017-08-28 14:01:09
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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.

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