143 research outputs found

    Structural plasticity, cortical memory, and the spacing effect

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    Cognitive Representations and Cognitive Processing of Team-Specific Tactics in Soccer

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    Lex H, Essig K, Knoblauch A, Schack T. Cognitive Representations and Cognitive Processing of Team-Specific Tactics in Soccer. PLoS ONE. 2015;10(2): e0118219.Two core elements for the coordination of different actions in sport are tactical information and knowledge about tactical situations. The current study describes two experiments to learn about the memory structure and the cognitive processing of tactical information. Experiment 1 investigated the storage and structuring of team-specific tactics in humans’ long-term memory with regard to different expertise levels. Experiment 2 investigated tactical decision-making skills and the corresponding gaze behavior, in presenting participants the identical match situations in a reaction time task. The results showed that more experienced soccer players, in contrast to less experienced soccer players, possess a functionally organized cognitive representation of team-specific tactics in soccer. Moreover, the more experienced soccer players reacted faster in tactical decisions, because they needed less fixations of similar duration as compared to less experienced soccer players. Combined, these experiments offer evidence that a functionally organized memory structure leads to a reaction time and a perceptual advantage in tactical decision-making in soccer. The discussion emphasizes theoretical and applied implications of the current results of the study

    Hierarchical and nonhierarchical features of the mouse visual cortical network

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    Neocortical computations underlying vision are performed by a distributed network of functionally specialized areas. Mouse visual cortex, a dense interareal network that exhibits hierarchical properties, comprises subnetworks interconnecting distinct processing streams. To determine the layout of the mouse visual hierarchy, we have evaluated the laminar patterns formed by interareal axonal projections originating in each of ten areas. Reciprocally connected pairs of areas exhibit feedforward/feedback relationships consistent with a hierarchical organization. Beta regression analyses, which estimate a continuous hierarchical distance measure, indicate that the network comprises multiple nonhierarchical circuits embedded in a hierarchical organization of overlapping levels. Single-unit recordings in anaesthetized mice show that receptive field sizes are generally consistent with the hierarchy, with the ventral stream exhibiting a stricter hierarchy than the dorsal stream. Together, the results provide an anatomical metric for hierarchical distance, and reveal both hierarchical and nonhierarchical motifs in mouse visual cortex

    Toward Self-Referential Autonomous Learning of Object and Situation Models

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    Most current approaches to scene understanding lack the capability to adapt object and situation models to behavioral needs not anticipated by the human system designer. Here, we give a detailed description of a system architecture for self-referential autonomous learning which enables the refinement of object and situation models during operation in order to optimize behavior. This includes structural learning of hierarchical models for situations and behaviors that is triggered by a mismatch between expected and actual action outcome. Besides proposing architectural concepts, we also describe a first implementation of our system within a simulated traffic scenario to demonstrate the feasibility of our approach

    Spatial embedding and wiring cost constrain the functional layout of the cortical network of rodents and primates

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    Mammals show a wide range of brain sizes, reflecting adaptation to diverse habitats. Comparing interareal cortical networks across brains of different sizes and mammalian orders provides robust information on evolutionarily preserved features and species-specific processing modalities. However, these networks are spatially embedded, directed, and weighted, making comparisons challenging. Using tract tracing data from macaque and mouse, we show the existence of a general organizational principle based on an exponential distance rule (EDR) and cortical geometry, enabling network comparisons within the same model framework. These comparisons reveal the existence of network invariants between mouse and macaque, exemplified in graph motif profiles and connection similarity indices, but also significant differences, such as fractionally smaller and much weaker long-distance connections in the macaque than in mouse. The latter lends credence to the prediction that long-distance cortico-cortical connections could be very weak in the much-expanded human cortex, implying an increased susceptibility to disconnection syndromes such as Alzheimer disease and schizophrenia. Finally, our data from tracer experiments involving only gray matter connections in the primary visual areas of both species show that an EDR holds at local scales as well (within 1.5 mm), supporting the hypothesis that it is a universally valid property across all scales and, possibly, across the mammalian class

    Binary Willshaw learning yields high synaptic capacity for long-term familiarity memory

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    We investigate from a computational perspective the efficiency of the Willshaw synaptic update rule in the context of familiarity discrimination, a binary-answer, memory-related task that has been linked through psychophysical experiments with modified neural activity patterns in the prefrontal and perirhinal cortex regions. Our motivation for recovering this well-known learning prescription is two-fold: first, the switch-like nature of the induced synaptic bonds, as there is evidence that biological synaptic transitions might occur in a discrete stepwise fashion. Second, the possibility that in the mammalian brain, unused, silent synapses might be pruned in the long-term. Besides the usual pattern and network capacities, we calculate the synaptic capacity of the model, a recently proposed measure where only the functional subset of synapses is taken into account. We find that in terms of network capacity, Willshaw learning is strongly affected by the pattern coding rates, which have to be kept fixed and very low at any time to achieve a non-zero capacity in the large network limit. The information carried per functional synapse, however, diverges and is comparable to that of the pattern association case, even for more realistic moderately low activity levels that are a function of network size.Comment: 20 pages, 4 figure

    DLR Design Challenge 2022: Design of a next generation VTOL firefighting aircraft

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    Since 2017, the German Aerospace Center (DLR) has been organizing an annual student competition on conceptual aircraft design titled DLR Design Challenge. This education and training initiative is set to challenge the next generation of aircraft designers with topics tailored to current research questions in the field of aeronautics. This year’s challenge was about the development of an aerial firefighting system of systems including vehicle and fleet design with a strong emphasize on operationally-driven design aspects. This paper proposes a design for a next generation vertical take-off and landing firefighting aircraft with an expected entry into service in 2030, that is working intelligently and interconnected in a group of four. The design won the DLR Design Challenge 2022 and the underlying work covers the preliminary design including the structural concept, aerodynamic simulations, weight and balance calculations and the concept for water intake and deployment. The designed aircraft is characterized by a considerable high payload ratio that features vertical take-off and landing capabilities while showing efficient horizontal flight properties with a very competitive cost basis. The 24-hr operability during various weather conditions and challenging fire scenarios is ensured using a wide variety of sensors and a modern glass-cockpit combining pilot comfort with indispensable safety aspects. Due to its modular design, every aircraft can be comfortably converted to a passenger or freight version during firefighting off-season or for cargo and crew supply during the missions
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