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Theories of Visual Attention - linking cognition, neuropsychology, and neurophysiology

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196371 Year: Pages: 112 DOI: 10.3389/978-2-88919-637-1 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Psychology
Added to DOAB on : 2016-08-16 10:34:25
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The Neural Theory of Visual Attention of Bundesen, Habekost, and Kyllingsbæk (2005) was proposed as a neural interpretation of Bundesen’s (1990) theory of visual attention (TVA). In NTVA, visual attention functions via two mechanisms: by dynamic remapping of receptive fields of cortical cells such that more cells are devoted to behaviorally important objects than to less important ones (filtering) and by multiplicative scaling of the level of activation in cells coding for particular features (pigeonholing). NTVA accounts for a wide range of known attentional effects in human performance and a wide range of effects observed in firing rates of single cells in the primate visual system and thus provides a mathematical framework to unify the 2 fields of research. In this Research Topic of Frontiers in Psychology, some of the leading theories of visual attention at both the cognitive, neuropsychological, and neurophysiological levels are presented and evaluated. In addition, the Research Topic encompasses application of the framework of NTVA to various patient populations and to neuroimaging as well as genetic and psychopharmacological studies.

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neural --- visual --- Attention --- computational --- Model

Modeling Disease Spread and Control

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889453849 Year: Pages: 133 DOI: 10.3389/978-2-88945-384-9 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Animal Sciences
Added to DOAB on : 2018-11-16 17:17:57
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Mathematical models are useful tools to understand the epidemiology and agent-host interaction of diseases. They are developed and applied since over a century, but with increasing computer capacity, they become increasingly prominent as part of evidence based decision making. Mathematical models are frequently used to construct preparedness and contingency plans for highly contagious diseases such as foot-and-mouth disease. This allows proposing effective strategies to control the spread of the disease in case of an incursion, and avails useful tools to support decision making during an outbreak. They are also used to monitor, prevent and control endemic diseases within populations or farms. In addition, mathematical models improve our understanding of the contact structure between farms, pointing out risky elements in the contact network for disease introduction or further spread within the population. This Research Topic presents valuable studies presenting different aspects and implementations of mathematical modeling for disease spread and control in the veterinary field. The areas covered include model construction, network analysis, tools for decision makers, and cost-effective control of endemic diseases.

New treatment perspectives in autism spectrum disorders

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195305 Year: Pages: 161 DOI: 10.3389/978-2-88919-530-5 Language: English
Publisher: Frontiers Media SA
Subject: Pediatrics --- Medicine (General)
Added to DOAB on : 2015-12-10 11:59:06
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Developing novel and more effective treatments that improve quality of life for individuals with autism spectrum disorders is urgently needed. To date a wide range of behavioral interventions have been shown to be safe and effective for improving language and cognition and adaptive behavior in children and adolescents with ASD. However many people with ASD can receive additional benefit from targeted pharmacological interventions. One of the major drawback in setting up therapeutics intervention is the remarkable individual differences found across individuals with ASD. As a matter of fact the medications that are currently available address only symptoms associated with ASD and not the core domains of social and communication dysfunction. The pathogenesis paradigm shift of ASD towards synaptic abnormalities moved the research to pathway to disease that involve multiple systems and that are becoming the forefront of ASD treatment and are pointing toward the development of new targeted treatments. Some new therapeutics have been tested and others are being studied. In this context single gene disorders frequently associated with ASD such as Rett Syndrome, Fragile X and Tuberous Sclerosis have been of significant aid as neurobiology of these disorders is more clear and has a potential to shed light on the altered signaling in ASD. However much research is needed to further understand the basic mechanisms of disease and the relationship to idiopathic ASD. Clinical trials in children are underway with agents directed to core symptoms and to the associated disorders in the search of new therapeutics and progress are expected with possible new option for therapeutics in ASD in the upcoming future. Children and Adolescents with ASD and their families can provide important information about their experience with new treatments and this should be a priority for future research. In addition, research performed on genetic mouse models of ASD will keep on providing useful information on the molecular pathways disrupted in the disease, thus contributing to identify novel drug targets.

Schizophrenia: A Consequence of Gene-Environment Interactions?

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195312 Year: Pages: 126 DOI: 10.3389/978-2-88919-531-2 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2015-12-10 11:59:06
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Schizophrenia is a multi-factorial disease characterized by a high heritability and environmental risk factors (e.g. stress and cannabis use). In recent years, an increasing number of researchers worldwide have started investigating the ‘two-hit hypothesis’ of schizophrenia predicting that genetic and environmental risk factors interactively cause the development of the disorder. This work is starting to produce valuable new animal models and reveal novel insights into the pathophysiology of schizophrenia. Eventually, it might help advance studies of the molecular pathways involved in this mental disorder and propose more specific molecular medicine. However, the complexity of this multi-factorial line of research has also caused difficulties in data interpretation and comparison. Our research topic is intended to cover past and current directions in research dedicated to the understanding and measurement of gene-environment interactions (GxE) in schizophrenia, the neurobiological and behavioural consequences of such interactions as well as the challenges and limitations one encounters when working on complex aetiological systems.

Sub-cellular Proteomics

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193028 Year: Pages: 254 DOI: 10.3389/978-2-88919-302-8 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Science (General)
Added to DOAB on : 2016-02-05 17:24:33
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Whilst significant advances have been made in whole organismal proteomics approaches, many researchers still rely on combinations of tissue selection and subcellular prefractionation methods to reduce the complexity of protein extracts from plants prior to proteomic analysis. Often this will allow identification of many lower abundance proteins of the target proteome and it may involve the selection of specific organs, cell types or the isolation of specific subcellular components. These subcellular proteomes provide insight into functions following various treatments and also contribute to the wider understanding of the entire organismal proteome by cataloguing a series of sub-proteome contents. The aim of this Research Topic is to bring together knowledge of sub cellular components in different plant species to provide a basis for accelerated research. It aims to provide a mini-review for each proposed section that summarizes the current understanding of a particular proteome, with the anticipation that every 5 - 10 years we can update these definitive publications.

Charophytes: Evolutionary Ancestors of Plants and Emerging Models for Plant Research

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451647 Year: Pages: 150 DOI: 10.3389/978-2-88945-164-7 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Science (General)
Added to DOAB on : 2017-08-28 14:01:09
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The charophytes are the group of green algae that are anestral and most closely related to land plants. Today, these organisms are not only important in evoutionary studies but have become outstanding model organisms for plant research.

Insight and Intuition - Two Sides of the Same Coin?

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889455195 Year: Pages: 168 DOI: 10.3389/978-2-88945-519-5 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Psychology
Added to DOAB on : 2019-01-23 14:53:42
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Insight and intuition might be the most mysterious and fascinating fields of human thinking and problem solving. They are different from standard and analytical problem solving accounts and provide the basis for creative and innovative thinking.Until now they were investigated in separate academic fields with differing tradition. Therefore, this eBook attempts to bridge the gap between both processes and to provide a more integrated perspective. Several experts address the underlying cognitive processes and provide a broad spectrum of new empirical, theoretical, and methodological insights.

Neural information processing with dynamical synapses

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193837 Year: Pages: 178 DOI: 10.3389/978-2-88919-383-7 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2015-12-03 13:02:24
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Experimental data have consistently revealed that the neuronal connection weight, which models the efficacy of the firing of a pre-synaptic neuron in modulating the state of a post-synaptic one, varies on short time scales, ranging from hundreds to thousands of milliseconds. This is called short-term plasticity (STP). Two types of STP, with opposite effects on the connection efficacy, have been observed in experiments. They are short-term depression (STD) and short-term facilitation (STF). Computational studies have explored the impact of STP on network dynamics, and found that STP can generate very rich intrinsic dynamical behaviors, including damped oscillations, state hopping with transient population spikes, traveling fronts and pulses, spiral waves, rotating bump states, robust self-organized critical activities and so on. These studies also strongly suggest that STP can play many important roles in neural computation. For instances, STD may provide a dynamic control mechanism that allows equal fractional changes on rapidly and slowly firing afferents to produce post-synaptic responses, realizing Weber's law; STD may provide a mechanism to close down network activity naturally, achieving iconic sensory memory; and STF may provide a mechanism for implementing work-memory not relying on persistent neural firing. From the computational point of view, the time scale of STP resides between fast neural signaling (in the order of milliseconds) and rapid learning (in the order of minutes or above), which is the time scale of many important temporal processes occurring in our daily lives, such as motion control and working memory. Thus, STP may serve as a substrate for neural systems manipulating temporal information on the relevant time scales. This Research Topic aims to present the recent progress in understanding the roles of STP in neural information processing. It includes, but no exclusively, the studies on investigating various computational roles of STP, the modeling studies on exploring new dynamical behaviors generated by STP, and the experimental works which help us to understand the functional roles of STP.

Using Noise to Characterize Vision

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197538 Year: Pages: 127 DOI: 10.3389/978-2-88919-753-8 Language: English
Publisher: Frontiers Media SA
Subject: Psychology --- Science (General)
Added to DOAB on : 2016-04-07 11:22:02
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Noise has been widely used to investigate the processing properties of various visual functions (e.g. detection, discrimination, attention, perceptual learning, averaging, crowding, face recognition), in various populations (e.g. older adults, amblyopes, migrainers, dyslexic children), using noise along various dimensions (e.g. pixel noise, orientation jitter, contrast jitter). The reason to use external noise is generally not to characterize visual processing in external noise per se, but rather to reveal how vision works in ordinary conditions when performance is limited by our intrinsic noise rather than externally added noise. For instance, reverse correlation aims at identifying the relevant information to perform a given task in noiseless conditions and measuring contrast thresholds in various noise levels can be used to understand the impact of intrinsic noise that limits sensitivity to noiseless stimuli. Why use noise? Since Fechner named it, psychophysics has always emphasized the systematic investigation of conditions that break vision. External noise raises threshold hugely and selectively. In hearing, Fletcher used noise in his famous critical-band experiments to reveal frequency-selective channels in hearing. Critical bands have been found in vision too. More generally, the big reliable effects of noise give important clues to how the system works. And simple models have been proposed to account for the effects of visual noise. As noise has been more widely used, questions have been raised about the simplifying assumptions that link the processing properties in noiseless conditions to measurements in external noise. For instance, it is usually assumed that the processing strategy (or mechanism) used to perform a task and its processing properties (e.g. filter tuning) are unaffected by the addition of external noise. Some have suggested that the processing properties could change with the addition of external noise (e.g. change in filter tuning or more lateral masking in noise), which would need to be considered before drawing conclusions about the processing properties in noiseless condition. Others have suggested that different processing properties (or mechanisms) could be solicited in low and high noise conditions, complicating the characterization of processing properties in noiseless condition based on processing properties identified in noise conditions. The current Research Topic probes further into what the effects of visual noise tell us about vision in ordinary conditions. Our Editorial gives an overview of the articles in this special issue.

The Evolving Telomeres

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198818 Year: Pages: 74 DOI: 10.3389/978-2-88919-881-8 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Genetics
Added to DOAB on : 2016-01-19 14:05:46
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What controls the different rates of evolution to give rise to conserved and divergent proteins and RNAs? How many trials until evolution can adapt to physiological changes? Every organism has arisen through multiple molecular changes, and the mechanisms that are employed (mutagenesis, recombination, transposition) have been an issue left to the elegant discipline of evolutionary biology. But behind the theory are realities that we have yet to ascertain: How does an evolving cell accommodate its requirements for both conserving its essential functions, while also providing a selective advantage? In this volume, we focus on the evolution of the eukaryotic telomere, the ribo-nuclear protein complex at the end of a linear chromosome. The telomere is an example of a single chromosomal element that must function to maintain genomic stability. The telomeres of all species must provide a means to avoid the attrition from semi-conservative DNA replication and a means of telomere elongation (the telomere replication problem). For example, telomerase is the most well-studied mechanism to circumvent telomere attrition by adding the short repeats that constitutes most telomeres. The telomere must also guard against the multiple activities that can act on an unprotected double strand break requiring a window (or checkpoint) to compensate for telomere sequence loss as well as protection against non-specific processes (the telomere protection problem). This volume describes a range of methodologies including mechanistic studies, phylogenetic comparisons and data-based theoretical approaches to study telomere evolution over a broad spectrum of organisms that includes plants, animals and fungi. In telomeres that are elongated by telomerases, different components have widely different rates of evolution. Telomerases evolved from roots in archaebacteria including splicing factors and LTR-transposition. At the conserved level, the telomere is a rebel among double strand breaks (DSBs) and has altered the function of the highly conserved proteins of the ATM pathway into an elegant means of protecting the chromosome end and maintaining telomere size homeostasis through a competition of positive and negative factors. This homeostasis, coupled with highly conserved capping proteins, is sufficient for protection. However, far more proteins are present at the telomere to provide additional species-specific functions. Do these proteins provide insight into how the cell allows for rapid change without self-destruction?

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