The Experts below are selected from a list of 215145 Experts worldwide ranked by ideXlab platform
Emmanuel Gilissen - One of the best experts on this subject based on the ideXlab platform.
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the distribution of ki 67 and doublecortin immunopositive cells in the brains of three strepsirrhine primates galago demidoff perodicticus potto and lemur catta
Neuroscience, 2017Co-Authors: Thandi T M Fasemore, Nina Patzke, Consolate Kaswerakyamakya, Emmanuel Gilissen, Paul R Manger, Amadi O IhunwoAbstract:Abstract This study investigated the pattern of adult neurogenesis throughout the brains of three prosimian primate species using immunohistochemical techniques for endogenous markers of this Neural Process. Two species, Galago demidoff and Perodicticus potto, were obtained from wild populations in the primary rainforest of central Africa, while one species, Lemur catta, was captive-bred. Two brains from each species, perfusion-fixed with 4% paraformaldehyde, were sectioned (50 µm section thickness) in sagittal and coronal planes. Using Ki-67 and doublecortin (DCX) antibodies, proliferating cells and immature neurons were identified in the two canonical neurogenic sites of mammals, the subventricular zone of the lateral ventricle (SVZ) giving rise to the rostral migratory stream (RMS), and the subgranular zone of the dentate gyrus of the hippocampus. In addition a temporal migratory stream (TMS), emerging from the temporal horn of the lateral ventricle to supply the piriform cortex and adjacent brain regions with new neurons, was also evident in the three prosimian species. While no Ki-67-immunoreactive cells were observed in the cerebellum, DCX-immunopositive cells were observed in the cerebellar cortex of all three species. These findings are discussed in a phylogenetic context.
Gregor Schöner - One of the best experts on this subject based on the ideXlab platform.
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How do Neural Processes give rise to cognition? Simultaneously predicting brain and behavior with a dynamic model of visual working memory.
Psychological review, 2021Co-Authors: Aaron T. Buss, Gregor Schöner, Vincent A. Magnotta, William D. Penny, Theodore J. Huppert, John P. SpencerAbstract:There is consensus that activation within distributed functional brain networks underlies human thought. The impact of this consensus is limited, however, by a gap that exists between data-driven correlational analyses that specify where functional brain activity is localized using functional magnetic resonance imaging (fMRI), and Neural Process accounts that specify how Neural activity unfolds through time to give rise to behavior. Here, we show how an integrative cognitive neuroscience approach may bridge this gap. In an exemplary study of visual working memory, we use multilevel Bayesian statistics to demonstrate that a Neural dynamic model simultaneously explains behavioral data and predicts localized patterns of brain activity, outperforming standard analytic approaches to fMRI. The model explains performance on both correct trials and incorrect trials where errors in change detection emerge from Neural fluctuations amplified by Neural interaction. Critically, predictions of the model run counter to cognitive theories of the origin of errors in change detection. Results reveal Neural patterns predicted by the model within regions of the dorsal attention network that have been the focus of much debate. The model-based analysis suggests that key areas in the dorsal attention network such as the intraparietal sulcus play a central role in change detection rather than working memory maintenance, counter to previous interpretations of fMRI studies. More generally, the integrative cognitive neuroscience approach used here establishes a framework for directly testing theories of cognitive and brain function using the combined power of behavioral and fMRI data. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Scene memory and spatial inhibition in visual search : A Neural dynamic Process model and new experimental evidence.
Attention Perception & Psychophysics, 2020Co-Authors: Raul Grieben, Jonas Lins, Sebastian Schneegans, Jan Tekulve, Stephan K. U. Zibner, Gregor SchönerAbstract:Any object-oriented action requires that the object be first brought into the attentional foreground, often through visual search. Outside the laboratory, this would always take place in the presence of a scene representation acquired from ongoing visual exploration. The interaction of scene memory with visual search is still not completely understood. Feature integration theory (FIT) has shaped both research on visual search, emphasizing the scaling of search times with set size when searches entail feature conjunctions, and research on visual working memory through the change detection paradigm. Despite its Neural motivation, there is no consistently Neural Process account of FIT in both its dimensions. We propose such an account that integrates (1) visual exploration and the building of scene memory, (2) the attentional detection of visual transients and the extraction of search cues, and (3) visual search itself. The model uses dynamic field theory in which networks of Neural dynamic populations supporting stable activation states are coupled to generate sequences of Processing steps. The Neural architecture accounts for basic findings in visual search and proposes a concrete mechanism for the integration of working memory into the search Process. In a behavioral experiment, we address the long-standing question of whether both the overall speed and the efficiency of visual search can be improved by scene memory. We find both effects and provide model fits of the behavioral results. In a second experiment, we show that the increase in efficiency is fragile, and trace that fragility to the resetting of spatial working memory.
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Scene memory and spatial inhibition in visual search
Attention Perception & Psychophysics, 2020Co-Authors: Raul Grieben, Jonas Lins, Sebastian Schneegans, Jan Tekulve, Stephan K. U. Zibner, Gregor SchönerAbstract:Any object-oriented action requires that the object be first brought into the attentional foreground, often through visual search. Outside the laboratory, this would always take place in the presence of a scene representation acquired from ongoing visual exploration. The interaction of scene memory with visual search is still not completely understood. Feature integration theory (FIT) has shaped both research on visual search, emphasizing the scaling of search times with set size when searches entail feature conjunctions, and research on visual working memory through the change detection paradigm. Despite its Neural motivation, there is no consistently Neural Process account of FIT in both its dimensions. We propose such an account that integrates (1) visual exploration and the building of scene memory, (2) the attentional detection of visual transients and the extraction of search cues, and (3) visual search itself. The model uses dynamic field theory in which networks of Neural dynamic populations supporting stable activation states are coupled to generate sequences of Processing steps. The Neural architecture accounts for basic findings in visual search and proposes a concrete mechanism for the integration of working memory into the search Process. In a behavioral experiment, we address the long-standing question of whether both the overall speed and the efficiency of visual search can be improved by scene memory. We find both effects and provide model fits of the behavioral results. In a second experiment, we show that the increase in efficiency is fragile, and trace that fragility to the resetting of spatial working memory.
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autonomously learning beliefs is facilitated by a Neural dynamic network driving an intentional agent
Joint IEEE International Conference on Development and Learning and Epigenetic Robotics, 2019Co-Authors: Jan Tekulve, Gregor SchönerAbstract:Intentionality is the capacity of mental states to be about the world, both in its “action” (world-to-mind) and its “perception” (mind-to-world) direction of fit. An intentional agent must be able to perceive, act, memorize, and plan. These psychological modes may be driven by desires and be informed by beliefs. We have previously proposed a Neural Process account of intentionality, in which intentional states are stabilized by interactions within populations of neurons that represent perceptual features and movement parameters. Instabilities in such Neural dynamics activated the conditions of satisfaction of intentional states and induced sequences of intentional behavior. Here we explore the idea that the Process organization of such intentional Neural systems enables autonomous learning. We show how beliefs may be learned from single experiences, may be activated in new situations, and be used to guide behavior. Beliefs may also be dis-activated when their predictions do not match experience, leading to the learning of a new belief. We demonstrate the idea in a simple scenario in which a simulated agent autonomously explores an environment, directs action at objects and learns simple contingencies in this environment to form beliefs. The beliefs can be used to realize fixed desires of the agent.
Amadi O Ihunwo - One of the best experts on this subject based on the ideXlab platform.
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the distribution of ki 67 and doublecortin immunopositive cells in the brains of three strepsirrhine primates galago demidoff perodicticus potto and lemur catta
Neuroscience, 2017Co-Authors: Thandi T M Fasemore, Nina Patzke, Consolate Kaswerakyamakya, Emmanuel Gilissen, Paul R Manger, Amadi O IhunwoAbstract:Abstract This study investigated the pattern of adult neurogenesis throughout the brains of three prosimian primate species using immunohistochemical techniques for endogenous markers of this Neural Process. Two species, Galago demidoff and Perodicticus potto, were obtained from wild populations in the primary rainforest of central Africa, while one species, Lemur catta, was captive-bred. Two brains from each species, perfusion-fixed with 4% paraformaldehyde, were sectioned (50 µm section thickness) in sagittal and coronal planes. Using Ki-67 and doublecortin (DCX) antibodies, proliferating cells and immature neurons were identified in the two canonical neurogenic sites of mammals, the subventricular zone of the lateral ventricle (SVZ) giving rise to the rostral migratory stream (RMS), and the subgranular zone of the dentate gyrus of the hippocampus. In addition a temporal migratory stream (TMS), emerging from the temporal horn of the lateral ventricle to supply the piriform cortex and adjacent brain regions with new neurons, was also evident in the three prosimian species. While no Ki-67-immunoreactive cells were observed in the cerebellum, DCX-immunopositive cells were observed in the cerebellar cortex of all three species. These findings are discussed in a phylogenetic context.
Nina Patzke - One of the best experts on this subject based on the ideXlab platform.
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the distribution of ki 67 and doublecortin immunopositive cells in the brains of three strepsirrhine primates galago demidoff perodicticus potto and lemur catta
Neuroscience, 2017Co-Authors: Thandi T M Fasemore, Nina Patzke, Consolate Kaswerakyamakya, Emmanuel Gilissen, Paul R Manger, Amadi O IhunwoAbstract:Abstract This study investigated the pattern of adult neurogenesis throughout the brains of three prosimian primate species using immunohistochemical techniques for endogenous markers of this Neural Process. Two species, Galago demidoff and Perodicticus potto, were obtained from wild populations in the primary rainforest of central Africa, while one species, Lemur catta, was captive-bred. Two brains from each species, perfusion-fixed with 4% paraformaldehyde, were sectioned (50 µm section thickness) in sagittal and coronal planes. Using Ki-67 and doublecortin (DCX) antibodies, proliferating cells and immature neurons were identified in the two canonical neurogenic sites of mammals, the subventricular zone of the lateral ventricle (SVZ) giving rise to the rostral migratory stream (RMS), and the subgranular zone of the dentate gyrus of the hippocampus. In addition a temporal migratory stream (TMS), emerging from the temporal horn of the lateral ventricle to supply the piriform cortex and adjacent brain regions with new neurons, was also evident in the three prosimian species. While no Ki-67-immunoreactive cells were observed in the cerebellum, DCX-immunopositive cells were observed in the cerebellar cortex of all three species. These findings are discussed in a phylogenetic context.
Thandi T M Fasemore - One of the best experts on this subject based on the ideXlab platform.
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the distribution of ki 67 and doublecortin immunopositive cells in the brains of three strepsirrhine primates galago demidoff perodicticus potto and lemur catta
Neuroscience, 2017Co-Authors: Thandi T M Fasemore, Nina Patzke, Consolate Kaswerakyamakya, Emmanuel Gilissen, Paul R Manger, Amadi O IhunwoAbstract:Abstract This study investigated the pattern of adult neurogenesis throughout the brains of three prosimian primate species using immunohistochemical techniques for endogenous markers of this Neural Process. Two species, Galago demidoff and Perodicticus potto, were obtained from wild populations in the primary rainforest of central Africa, while one species, Lemur catta, was captive-bred. Two brains from each species, perfusion-fixed with 4% paraformaldehyde, were sectioned (50 µm section thickness) in sagittal and coronal planes. Using Ki-67 and doublecortin (DCX) antibodies, proliferating cells and immature neurons were identified in the two canonical neurogenic sites of mammals, the subventricular zone of the lateral ventricle (SVZ) giving rise to the rostral migratory stream (RMS), and the subgranular zone of the dentate gyrus of the hippocampus. In addition a temporal migratory stream (TMS), emerging from the temporal horn of the lateral ventricle to supply the piriform cortex and adjacent brain regions with new neurons, was also evident in the three prosimian species. While no Ki-67-immunoreactive cells were observed in the cerebellum, DCX-immunopositive cells were observed in the cerebellar cortex of all three species. These findings are discussed in a phylogenetic context.
