67 research outputs found

    Gamma oscillations as integrators of local competition for activity and global competition for coherence

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    Poster presentation: Introduction Rhythmic synchronization of neural activity in the gamma-frequency range (30–100 Hz) was observed in many brain regions; see the review in [1]. The functional relevance of these oscillations remains to be clarified, a task that requires modeling of the relevant aspects of information processing. The temporal correlation hypothesis, reviewed in [2], proposes that the temporal correlation of neural units provides a means to group the neural units into so-called neural assemblies that are supposed to represent mental objects. Here, we approach the modeling of the temporal grouping of neural units from the perspective of oscillatory neural network systems based on phase model oscillators. Patterns are assumed to be stored in the network based on Hebbian memory and assemblies are identified with phase-locked subset of these patterns. Going beyond foregoing discussions, we demonstrate the combination of two recently discussed mechanisms, referred to as "acceleration" [3] and "pooling" [4]. The combination realizes in a complementary manner a competition for activity on a local scale, while providing a competition for coherence among different assemblies on a non-local scale. ..

    A global decision-making model via synchronization in macrocolumn units

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    Poster presentation: Introduction We here address the problem of integrating information about multiple objects and their positions on the visual scene. A primate visual system has little difficulty in rapidly achieving integration, given only a few objects. Unfortunately, computer vision still has great difficultly achieving comparable performance. It has been hypothesized that temporal binding or temporal separation could serve as a crucial mechanism to deal with information about objects and their positions in parallel to each other. Elaborating on this idea, we propose a neurally plausible mechanism for reaching local decision-making for "what" and "where" information to the global multi-object recognition. ..

    Circuit Analysis and Design using Evolutionary Algorithms

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    This paper focuses on electronic design at circuit level. The use of evolutionary algorithms to this application is discussed and a trade off to existing approaches is investigated. The design and analyzing task at this level is described in detail. As example a 1-bit full adder design in static CMOS is inspected with regard to power consumption and delay. In algorithmic scope both, single- and multi-objective optimization are regarded here. Finally some concluding remarks are given in section 6. ircuit Optimization Electronic design at circuit-level is a numeric adjustment process to meet constraints and goals on a fixed structure. Parameter extraction and variation, simulation, and resul

    Circuit Analysis and Design using Evolutionary Algorithms

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    This paper focuses on electronic design at circuit level. The use of evolutionary algorithms to this application is discussed and a trade off to existing approaches is investigated. The design and analyzing task at this level is described in detail. As example a 1-bit full adder design in static CMOS is inspected with regard to power consumption and delay. In algorithmic scope both, single- and multi-objective optimization are regarded here

    Towards Quantum Cosmology without Singularities

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    In this paper we investigate the vanishing of cosmological singularities by quantization. Starting from a 5d Kaluza--Klein approach we quantize, as a first step, the non--spherical metric part and the dilaton field. These fields which are classically singular become smooth after quantization. In addition, we argue that the incorporation of non perturbative quantum corrections form a dilaton potential. Technically, the procedure corresponds to the quantization of 2d dilaton gravity and we discuss several models. From the 4d point of view this procedure is a semiclassical approach where only the dilaton and moduli matter fields are quantized.Comment: 9 pages, 2 figures, Latex, epsfig.sty, epsf.te

    The complex genetics of multiple sclerosis: pitfalls and prospects

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    The genetics of complex disease is entering a new and exciting era. The exponentially growing knowledge and technological capabilities emerging from the human genome project have finally reached the point where relevant genes can be readily and affordably identified. As a result, the last 12 months has seen a virtual explosion in new knowledge with reports of unequivocal association to relevant genes appearing almost weekly. The impact of these new discoveries in Neuroscience is incalculable at this stage but potentially revolutionary. In this review, an attempt is made to illuminate some of the mysteries surrounding complex genetics. Although focused almost exclusively on multiple sclerosis all the points made are essentially generic and apply equally well, with relatively minor addendums, to any other complex trait, neurological or otherwise

    Maria Cosway’s Hours: Cosmopolitan and Classical Visual Culture in Thomas Macklin’s Poets Gallery

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    Thomas Macklin’s Gallery of Poets opened at the Mitre Tavern in Fleet Street in 1788 with the aim to ‘display British Genius’ through ‘Prints Illustrative of the Most Celebrated British Poets’. Early newspaper coverage promised ‘a monument of the powers of the pencil in England, as the Vatican is at Rome’. The incongruous juxtaposition between Fleet Street and the Vatican spells out the cosmopolitan ambition of the literary gallery phenomenon through its real and imagined geographies of display. Through the format of the paper gallery of prints, Macklin’s Poets offered the inventions of British Poets as a repository of painting. This chapter examines how the cosmopolitan idiom of the paper gallery is negotiated in the first number of Macklin’s Poets. This essay examines the extent to which this ambition was achieved in the first Number of Macklin’s Poets which carried an engraving of Maria Cosway’s The Hours, originally a painting with an impressively European iconographic heritage. The painting was first exhibited at the Royal Academy in 1783, and was retroactively associated by Macklin with Thomas Gray’s ‘Ode on the Spring’. The trope of the Hours brought with it a weighty provenance derived from classical marble bas-relief, through the antiquarian pages of Pietro Santi Bartoli and Bernard de Montfaucon to Flaxman’s designs for Wedgwood plaques and vases. Cosway’s name also imported into Gray’s poem her reputation as a cosmopolitan, cultured woman who had completed the Grand Tour and who moved in elite circles including those of the Prince of Wales in London and the Duke of Orleans, Pierre d’Hancarville and Thomas Jefferson in Paris. The iconographies of the painting, the print, and the poem articulate a European cosmopolitan tradition for British Art

    26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

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    This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)
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