20,159 research outputs found

    Deciphering the brain's codes

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    The two sensory systems discussed use similar algorithms for the synthesis of the neuronal selectivity for the stimulus that releases a particular behavior, although the neural circuits, the brain sites involved, and even the species are different. This stimulus selectivity emerges gradually in a neural network organized according to parallel and hierarchical design principles. The parallel channels contain lower order stations with special circuits for the creation of neuronal selectivities for different features of the stimulus. Convergence of the parallel pathways brings these selectivities together at a higher order station for the eventual synthesis of the selectivity for the whole stimulus pattern. The neurons that are selective for the stimulus are at the top of the hierarchy, and they form the interface between the sensory and motor systems or between sensory systems of different modalities. The similarities of these two systems at the level of algorithms suggest the existence of rules of signal processing that transcend different sensory systems and species of animals

    Integrated sensors for robotic laser welding

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    A welding head is under development with integrated sensory systems for robotic laser welding applications. Robotic laser welding requires sensory systems that are capable to accurately guide the welding head over a seam in three-dimensional space and provide information about the welding process as well as the quality of the welding result. In this paper the focus is on seam tracking. It is difficult to measure three-dimensional parameters of a ream during a robotic laser welding task, especially when sharp corners are present. The proposed sensory system is capable to provide the three dimensional parameters of a seam in one measurement and guide robots over sharp corners

    Auditory pathways: are 'what' and 'where' appropriate?

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    New evidence confirms that the auditory system encompasses temporal, parietal and frontal brain regions, some of which partly overlap with the visual system. But common assumptions about the functional homologies between sensory systems may be misleading

    Mechanisms for vestibular disorders in space flight. Facts and hypotheses

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    This article discusses the vestibular disorders associated with space flight. It is found there is still no complete understanding of the changes occurring in the sensory systems of the body during weightlessness. Results of studies are presented, including results of a ground model

    Dynamical aspects of Kinouchi-Copelli model: emergence of avalanches at criticality

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    We analyze the behavior of bursts of neural activity in the Kinouchi-Copelli model, originally conceived to explain information processing issues in sensory systems. We show that, at a critical condition, power-law behavior emerges for the size and duration of the bursts (avalanches), with exponents experimentally observed in real biological systems.Comment: Paper accepted for Brazilian Conference on Dynamics, Control and Applications (oral presentation and poster). 4 pages, 5 figure

    Plasticity in invertebrate sensory systems

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    The visual, olfactory, auditory and gustatory systems of invertebrates are often used as models to study the transduction, transmission and processing of information in nervous systems, and in recent years have also provided powerful models of neural plasticity. This Research Topic presents current views on plasticity and its mechanisms in invertebrate sensory systems at the cellular, molecular and network levels, approached from both physiological and morphological perspectives. Plasticity in sensory systems can be activity- dependent, or occur in response to changes in the environment, or to endogenous stimuli. Plastic changes have been reported in receptor neurons, but are also known in other cell types, including glial cells and sensory interneurons. Also reported are dynamic changes among neuronal circuits involved in transmitting sensory stimuli and in reorganizing of synaptic contacts within a particular sensory system. Plastic changes within sensory systems in invertebrates can also be reported during development, after injury and after short or long- term stimulation. All these changes occur against an historical backdrop which viewed invertebrate nervous systems as largely hard-wired, and lacking in susceptibility especially to activity-dependent changes. This Research Topic examines how far we have moved from this simple view of simple brains, to the realization that invertebrate sensory systems exhibit all the diversity of plastic changes seen in vertebrate brains, but among neurons in which such changes can be evaluated at single-cell level
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