Visual Attention In Primates And For Machines Neuronal Mechanisms
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Visual Attention In Primates And For Machines Neuronal Mechanisms
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Author : Frederik Beuth
language : en
Publisher:
Release Date : 2020-11-02
Visual Attention In Primates And For Machines Neuronal Mechanisms written by Frederik Beuth and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-11-02 with categories.
Attention Filtering Of Visual Information By Prefrontal Cortex Neural Ensembles
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Author : Sebastien Tremblay
language : en
Publisher:
Release Date : 2015
Attention Filtering Of Visual Information By Prefrontal Cortex Neural Ensembles written by Sebastien Tremblay and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
"Selective attention is the cognitive process by which processing resources are preferentially attributed to behaviourally relevant sensory stimulations. Single electrode studies in the macaque monkey brain have identified the single neuron correlates of this selection process within both sensory and higher-order associative areas. However, the neural ensemble correlates of this cognitive process remain poorly documented. In this doctoral thesis, I have studied the neural ensemble correlates of visual attention within the primate lateral prefrontal cortex using multielectrode recording techniques.First, I have employed computational tools borrowed from the field of machine learning to extract the attentional information contained in the spiking activity of prefrontal neural ensembles. I was able to predict the focus of attention from this activity on a single-trial basis, indicating that this region could drive the attentional selection process within behaviourally relevant timeframes. Second, I have compared the spiking activity of the neural ensembles to the local field potential activity, which is composed of low frequency voltage oscillations within the extracellular space. I found that attention could be decoded in a frequency-dependent manner from these signals. Moreover, I found evidence that high-frequency gamma oscillations are mostly reflecting spiking activity.Finally, by combining the previous approach with a pharmacological intervention, I have found that methylphenidate, the most widely prescribed drug to treat attention deficit disorders, reduces inter-neuronal interactions that are detrimental to information coding. I have also shown that this network effect of the drug leads to improved coding of attentional signals by prefrontal cortex neural ensembles.Overall, these results will help further our basic understanding of the neural mechanisms by which the prefrontal cortex supports attentional functions in the primate brain. In addition, it should illuminate new clinical research avenues aimed at designing better treatments for children and adults with attention deficit disorders." --
Visual Attention Mechanisms
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Author : Virginio Cantoni
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-12-06
Visual Attention Mechanisms written by Virginio Cantoni and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-12-06 with Computers categories.
Proceedings of the Fifth International School on Neural Networks "E.R. Caianiello" on Visual Attention MechaProceedings of the Fifth International School on Neural Networks "E.R. Caianiello" on Visual Attention Mechanisms, held 23-28 October 2000 in Vietri sul Mare, Italy.nisms, held 23-28 October 2000 in Vietri sul Mare, Italy. The book covers a number of broad themes relevant to visual attention, ranging from computer vision to psychology and physiology of vision. The main theme of the book is the attention processes of vision systems and it aims to point out the analogies and the divergences of biological vision with the frameworks introduced by computer scientists in artificial vision.
Mechanisms Of Attentional Filtering In Neuronal Ensembles Of Primate Prefrontal Cortex
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Author : Theda Backen
language : en
Publisher:
Release Date : 2017
Mechanisms Of Attentional Filtering In Neuronal Ensembles Of Primate Prefrontal Cortex written by Theda Backen and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with categories.
"Visual attention describes the cognitive mechanism that selectively filters behaviorally relevant from irrelevant information. Neurophysiological studies using single unit recordings have uncovered a network of fronto-parietal brain areas involved in the allocation of attention. However, important details regarding how ensembles of simultaneously active neurons support this behavior remain poorly documented. In this doctoral thesis, I investigated how neuronal ensembles within the primate lateral prefrontal cortex (LPFC) underlie attentional filtering under varying behavioral conditions. I first showed that ensemble activity correlates with behavior in a task during which the task difficulty was manipulated by changing the distance between ordinally-ranked stimuli. Behavioral performance improved with decreasing task difficulty and similarly, neuronal ensembles encoded the spatial location of the attended stimulus more accurately for easier trials. Furthermore, interactions between similarly and dissimilarly tuned neurons also co-varied with task difficulty. However, these patterns of spike count correlations had no measurable effect on information coding in the neuronal population. Instead, I postulate a model that describes all measured ensemble properties, in which these spike count correlations reflect anatomical and functional connectivity patterns of the underlying neuronal circuits. Second, I investigated how LPFC neurons encode different task-relevant stimulus parameters. I found evidence that neuronal ensembles encode both spatial and non-spatial features of attended stimuli more accurately than single units. Those results indicate that LPFC may be relevant for both types of attention but also highlight that the information contained in such maps cannot be predicted from the responses of individual units. Finally, I examined how the spatial arrangement of stimuli modulates attention. When two stimuli were presented within the same hemifield, behavioral performance as well as neuronal attentional filtering performance was impaired. I offer evidence that a change in the underlying correlational structure of the ensemble may affect information coding. These results give credence to the hypothesis that attentional capacities are hemifield-independent. Taken together, these results provide important new insight into the neural ensemble correlates of visual attention. Ensemble activity in the lateral prefrontal cortex of primates appears to be critically involved in attentional filtering under a variety of behavioral conditions. " --
Theories Of Visual Attention Linking Cognition Neuropsychology And Neurophysiology
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Author : Søren Kyllingsbæk
language : en
Publisher: Frontiers Media SA
Release Date : 2015-09-02
Theories Of Visual Attention Linking Cognition Neuropsychology And Neurophysiology written by Søren Kyllingsbæk and has been published by Frontiers Media SA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-09-02 with Psychology categories.
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.
What Can Simple Brains Teach Us About How Vision Works
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Author : Davide Zoccolan
language : en
Publisher: Frontiers Media SA
Release Date : 2015-11-18
What Can Simple Brains Teach Us About How Vision Works written by Davide Zoccolan and has been published by Frontiers Media SA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-11-18 with Neurosciences. Biological psychiatry. Neuropsychiatry categories.
Vision is the process of extracting behaviorally-relevant information from patterns of light that fall on retina as the eyes sample the outside world. Traditionally, nonhuman primates (macaque monkeys, in particular) have been viewed by many as the animal model-of-choice for investigating the neuronal substrates of visual processing, not only because their visual systems closely mirror our own, but also because it is often assumed that “simpler” brains lack advanced visual processing machinery. However, this narrow view of visual neuroscience ignores the fact that vision is widely distributed throughout the animal kingdom, enabling a wide repertoire of complex behaviors in species from insects to birds, fish, and mammals. Recent years have seen a resurgence of interest in alternative animal models for vision research, especially rodents. This resurgence is partly due to the availability of increasingly powerful experimental approaches (e.g., optogenetics and two-photon imaging) that are challenging to apply to their full potential in primates. Meanwhile, even more phylogenetically distant species such as birds, fish, and insects have long been workhorse animal models for gaining insight into the core computations underlying visual processing. In many cases, these animal models are valuable precisely because their visual systems are simpler than the primate visual system. Simpler systems are often easier to understand, and studying a diversity of neuronal systems that achieve similar functions can focus attention on those computational principles that are universal and essential. This Research Topic provides a survey of the state of the art in the use of animal models of visual functions that are alternative to macaques. It includes original research, methods articles, reviews, and opinions that exploit a variety of animal models (including rodents, birds, fishes and insects, as well as small New World monkey, the marmoset) to investigate visual function. The experimental approaches covered by these studies range from psychophysics and electrophysiology to histology and genetics, testifying to the richness and depth of visual neuroscience in non-macaque species.
Circuits Underlying Visual Attention In Primate Neocortex
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Author : Nicholas A. Steinmetz
language : en
Publisher:
Release Date : 2014
Circuits Underlying Visual Attention In Primate Neocortex written by Nicholas A. Steinmetz and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
Humans and many other species attend to only a small portion of available visual information at any given moment. They enhance perception of the attended stimulus either overtly, making an eye or head movement to orient toward it, or covertly, without any such movements. The neural circuits that underlie these two types of attention behaviors, and the relationship between them, remain unclear. To investigate the interdependence of them we trained monkeys on a task that behaviorally dissociated the location of covert attention from the location of a saccade target. Recordings in extrastriate visual cortical area V4 surprisingly revealed that enhanced firing rates and other modulations of neural activity accompanied both covert attention and saccade preparation. These results suggested a hypothesis about the circuits that could mediate the control of both behaviors. We recorded neurons in the frontal eye field, an area involved in controlling both behaviors, and found evidence contradicting our hypothesis. Separately, we examined the circuit underlying the integration of attention-related feedback signals with visual information in visual cortex by recording from distinct neuron populations, defined by laminar depth, within V4 during the covert attention task. We found that all neuron populations were modulated indistinguishably during attention. Finally, we constructed a large-scale model of FEF and V4 on neuromorphic hardware and used it to investigate a novel hypothesis about the way feedback from FEF influences V4, namely, via NMDA synapses. This model makes predictions for future experiments that could help uncover the mechanism of attention-related modulation of visual cortex. Taken together, these results have helped to elucidate our understanding of the circuits within and between frontal and visual cortical areas underlying attention.
Feature Based Attention In Primate Visual Cortex
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Author : Philipp Schwedhelm
language : de
Publisher:
Release Date : 2015
Feature Based Attention In Primate Visual Cortex written by Philipp Schwedhelm and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
The scope of this thesis, after a brief summary of the core ideas of top-down attentional control is given (Chapter 2.1), is to shed some light on the cortical control circuit underlying the deployment of feature-based attention. A first study (Chapter 2.2) deduces from human psychophysical performance how an attentional signal acts on a local sensory population of motion-selective neurons. A second empirical study (Chapter 2.3) attempts to identify and characterize resource limitations for the deployment of feature-based attention in macaque monkeys. In particular, the aim of the study was...
Feature Based Attention In Primate Visual Cortex
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Author : Philipp Schwedhelm
language : de
Publisher:
Release Date : 2015
Feature Based Attention In Primate Visual Cortex written by Philipp Schwedhelm and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
The scope of this thesis, after a brief summary of the core ideas of top-down attentional control is given (Chapter 2.1), is to shed some light on the cortical control circuit underlying the deployment of feature-based attention. A first study (Chapter 2.2) deduces from human psychophysical performance how an attentional signal acts on a local sensory population of motion-selective neurons. A second empirical study (Chapter 2.3) attempts to identify and characterize resource limitations for the deployment of feature-based attention in macaque monkeys. In particular, the aim of the study was ...
Neural Mechanisms Of Selective Attention To Visual Features
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Author : Sean Patrick Fannon
language : en
Publisher:
Release Date : 2006
Neural Mechanisms Of Selective Attention To Visual Features written by Sean Patrick Fannon and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with Attention categories.