Neural Mechanisms Of Spatial Attention
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Neural Mechanisms Of Spatial Attention
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Author : Ashley Royston
language : en
Publisher:
Release Date : 2018
Neural Mechanisms Of Spatial Attention written by Ashley Royston and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with categories.
Elucidating the neural bases of selective attention continues to be a key challenge for psychologists, vision scientists and cognitive neuroscientists. It also represents an essential aim in translational efforts to measure, treat and prevent visual and attentional deficits, to improve teaching and learning, and to tailor automated situational awareness and alerting systems to human capabilities. Past human functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) studies, as well as animal electrophysiological studies, have provided considerable information about the temporal properties, neuroanatomical substrates, and cellular- and synaptic-level mechanisms underlying attention. Despite substantial convergence in the mechanisms of attention revealed by these different approaches, there remain significant unresolved quandaries in the scientific literature. In particular, it is currently debated whether attention can influence neural activity during the initial feedforward wave of visual processing in human primary visual cortex (V1). FMRI in humans and cellular recordings in monkeys both suggest spatial attention can influence afferent sensory processing in V1. In sharp contrast, however, such effects of attention have not been reliably reported for human EEG recordings; the short-latency C1 component of the visually evoked event-related potential (ERP) that is generated in V1 is typically not affected by selective attention. Given the fMRI findings and the animal studies, what can explain this discrepancy? FMRI activations are tied to slow changes in cerebral hemodynamics that cannot distinguish between attention effects on incoming signals and activations due to longer-latency feedback activation of V1 from higher stages of visual processing—therefore, fMRI evidence is equivocal regarding whether attention-related V1 activations represent modulations of feedforward or feedback V1 activity. However, human and animal electrophysiology both provide the temporal resolution to distinguished between initial afferent volleys and feedback activity, making it difficult to reconcile the positive findings in monkeys and the negative findings in humans. The overarching hypothesis of this dissertation is that differences in the methods and paradigms between monkey and human studies could contribute to the differences in attention effects in V1. Specifically, monkey studies typically use continuous stimulation that is arguably more similar to natural vision than the punctate stimulation paradigms (e.g., trial-by-trial spatial cuing) often used in humans to study the effects of attention on sensory processing. Ongoing stimulation may trigger attention-related feedback signals from higher areas onto V1 that might not arise, or might not be observable, when simple, single, isolated stimuli are used. To investigate whether the nature of ongoing visual stimulation may account for some of the discrepancies reported in the literature, this dissertation examines human ERPs recorded during selective attention in six variations of a novel spatial attention task that builds on a paradigm successfully used to reveal V1 attention effects in nonhuman primates. Using this task, significant effects of spatial attention were observed on the amplitude of the C1 ERP in humans (Chapter 2). The addition of high-resolution eye gaze monitoring, however, demonstrated that small, systematic deviations of eye gaze in the direction of the cue hemifield likely contributed to the Chapter 2 finding, and when data from trials with deviations of eye gaze were eliminated, no attentional modulation on the C1 ERP remained (Chapter 3). Therefore, the main hypothesis that stimulus-triggered feedback attentional modulation of V1 signals should be observed as changes in C1 ERP amplitude, was not supported. Although the present findings do not explain the differences between spatial attention effects in monkey and human V1, they do provide additional support for the model that spatial attention effects observed using fMRI in humans is likely not the result of changes in input signal processing in V1, but instead reflects later recurrent activation of V1 that serves other computational purposes.
Neural Mechanisms Mediating Voluntary Shifts Of Spatial Attention
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Author : Jessica J. Green
language : en
Publisher:
Release Date : 2006
Neural Mechanisms Mediating Voluntary Shifts Of Spatial Attention written by Jessica J. Green and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with Cognitive neuroscience categories.
The neural mechanisms underlying voluntary shifts of spatial attention were investigated by examining the event-related potentials (ERPs) to attention-directing cues and associated changes in alpha-band (8-14 Hz) electroencephalographic (EEG) activity. Intramodal auditory and visual shifts of attention were examined in Experiments 1 and 2, and crossmodal shifts of attention were examined in Experiments 3 and 4. Different patterns of ERP and alpha-band activities were observed across the four experiments. Frontal ERP activity (ADAN) was elicited by visual cues but not by auditory cues, which disconfirms previous claims that that this frontal activity reflects supramodal attentional control processes. Posterior ERP activity (LDAP) and associated changes in alpha-band EEG oscillations were observed in all experiments, but the scalp topographies of these activities depended on the modality of the task-relevant target. Such topographic differences suggest that the posterior ERP and alpha-band activities reflect attentional preparation in sensory-specific regions of cortex.
Neural Mechanisms Of Visuo Spatial Attention In School Aged Children
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Author : Na Yeon Kim
language : en
Publisher:
Release Date : 2021
Neural Mechanisms Of Visuo Spatial Attention In School Aged Children written by Na Yeon Kim and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with categories.
Selective attention, the ability to focus on key information and filter out noise, is crucial for navigating the cluttered world. The neural basis of selective attention has been widely studied in the adult brain. However, much less is known about how selective attention operates and develops in children's brain. Using neuroimaging, this dissertation investigates visuo-spatial selective attention in school children (ages 6 to 12). It employs a framework that is grounded in biased competition theory in order to probe each part of the neural mechanisms underlying selective attention functions. The first study demonstrates sensory competition in children's visual cortex, providing a foundation for investigations of sensory-driven and goal-driven mechanisms that modulate the competition. The second study examines the extent to which children's visual system can use perceptual grouping principles, as one of the sensory-driven mechanisms. Evidence suggests that perceptual grouping in visual cortex continues to refine beyond age 6, which could serve as a bottleneck for efficient selective processing. The third study shows that the fronto-parietal attention network, a source of goal-driven attention control, matures by achieving a balance between the two hemispheres. Using a perceptual line bisection task, it demonstrates that children in early elementary grades (ages 6 to 8) show an attention bias towards the left-hand side of space, which gradually diminishes and becomes adult-like by middle school ages (ages 11 to 13). It also shows that the degree of spatial bias is linked to functional connectivity patterns within each child's attention network. Interestingly, such leftward biases in children are related to their reading fluency, suggesting an interaction between the attention network and the reading network across development. Together, this work demonstrates that the development of visuo-spatial selective attention in childhood is a dynamic process that is shaped by sensory processing and cognitive skills that continue to change throughout this age range. Interactions with perceptual functions and newly acquired cognitive skills should be addressed in order to better characterize the typical and atypical development of visuo-spatial selective attention.
Neural Mechanisms Of Visuo Spatial Attention And Fear Processing
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Author : Felix Bacigalupo
language : en
Publisher:
Release Date : 2016
Neural Mechanisms Of Visuo Spatial Attention And Fear Processing written by Felix Bacigalupo and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Attention is a fundamental cognitive process that attempts to select relevant stimuli from among irrelevant distractors. Attention is altered in several neuro-psychiatric conditions such as anxiety and trauma-related disorders, in which fear also plays an important role. Thus, the study of the interaction between attention and fear could help us to understand the pathophysiology of highly prevalent and disabling conditions such as posttraumatic stress disorder (PTSD). For many years, the neural mechanisms of visuo-spatial attention have been studied by measuring the N2pc component of the event-related potential (ERP) waveform. A newer attention-related neural signal is lateralized alpha-band activity. Although both the N2pc component and lateralized alpha-band activity are considered markers of attention and are obtained by examining lateralizations in electroencephalographic signals, no prior research has examined whether these two measures reflect the same or different neural mechanisms of visuo-spatial attention. In a series of experiments, we found that the N2pc and the lateralized alpha-band are separate, dissociable signatures of visual attention. To begin to link attention and fear using ERPs, we conducted a study to develop a new ERP approach to measure fear learning using the late positive potential (LPP). We found that the LPP was a sensitive marker of fear conditioning and that it has several advantages over the traditional measure, the skin conductance response (SCR). Finally, using an attentional paradigm in which targets and distractors were associated with fear, we provided evidence supporting the hypothesis that fear-induced arousal modulates spatial attention in a generalized manner. These results not only provide new insights for understanding the basic neural processes underlying visuo-spatial attention but also allow us to have better models of the interaction between attention and fear, which may someday be useful to help patients suffering from anxiety and trauma-related disorders.
Orienting Of Attention
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Author : Richard D. Wright
language : en
Publisher: Oxford University Press
Release Date : 2008-04-16
Orienting Of Attention written by Richard D. Wright and has been published by Oxford University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008-04-16 with Psychology categories.
This book is a succinct introduction to the orienting of attention. Richard Wright and Lawrence Ward describe the covert orienting literature clearly and concisely, illustrating it with numerous high-quality images, specifically designed to make the challenging theoretical concepts very accessible. The book begins with an historical introduction that provides a great deal of information about orienting, much of which will be new even to seasoned researchers. Wright and Ward then systematically describe the development of various experimental paradigms that have been devised to study covert orienting, and the theoretical issues raised by this research. One trend that they analyze in detail is the progression from relatively simple models of spatial attention (attention spotlight and zoom lens models) to an integrative computational framework based on a concept called the "activity distribution." They also present a comprehensive survey of cognitive neuroscience research on the brain mechanisms underlying spatial attention shifts, as well as a chapter summarizing recent research on crossmodal attention shifts, and elucidating the links between attention orienting in the visual, auditory, and tactile domains. In the Epilogue they offer a concise summary of the book, and develop preliminary frameworks for understanding the relationship between spatial attention and orienting in response to social cues (social cognitive neuroscience) and for describing the evolution of covert orienting. Orienting of Attention provides a systematic survey that is ideal for those looking for an accessible introduction to the field and also for students and researchers who want a state-of the-art overview.
The Neuroscience Of Attention The Neuroscience Of Attention
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Author : George R. Mangun
language : en
Publisher: Oxford University Press
Release Date : 2012-02-16
The Neuroscience Of Attention The Neuroscience Of Attention written by George R. Mangun and has been published by Oxford University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-02-16 with Medical categories.
This book will provide the reader with a solid overview of the mechanisms and models in the neuroscience of attentional control and selection from leading authorities working in humans and animals, and incorporating a array of neuroscience methods from single neuron recordings to functional brain imaging.
The Oxford Handbook Of Attention
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Author : Kia Nobre
language : en
Publisher: Oxford University Press
Release Date : 2018
The Oxford Handbook Of Attention written by Kia Nobre and has been published by Oxford University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with Medical categories.
During the last three decades, there have been enormous advances in our understanding of the neural mechanisms of selective attention at the network as well as the cellular level. The Oxford Handbook of Attention brings together the different research areas that constitute contemporary attention research into one comprehensive and authoritative volume. In 40 chapters, it covers the most important aspects of attention research from the areas of cognitive psychology, neuropsychology, human and animal neuroscience, computational modelling, and philosophy. The book is divided into 4 main sections. Following an introduction from Michael Posner, the books starts by looking at theoretical models of attention. The next two sections are dedicated to spatial attention and non-spatial attention respectively. Within section 4, the authors consider the interactions between attention and other psychological domains. The last two sections focus on attention-related disorders, and finally, on computational models of attention. Aimed at both scholars and students, the Oxford Handbook of Attention provides a concise and state-of-the-art review of the current literature in this field.
The Cognitive And Neural Bases Of Spatial Neglect
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Author : Hans-Otto Karnath
language : en
Publisher: Oxford University Press, USA
Release Date : 2002
The Cognitive And Neural Bases Of Spatial Neglect written by Hans-Otto Karnath and has been published by Oxford University Press, USA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2002 with Medical categories.
Spatial neglect is a disorder of space-related behaviour. It is characterized by failure to explore the side of space contralateral to a brain lesion, or to react or respond to stimuli or subjects located on this side. Research on spatial neglect and related disorders has developed rapidly inrecent years. These advances have been made as a result of neuropsychological studies of patients with brain damage, behavioural studies of animal models, as well as through functional neurophysiological experiments and functional neuroimaging.The Cognitive and Neural Bases of Spatial Neglect provides an overview of this wide-ranging field of scientific endeavour, providing a cohesive synthesis of the most recent observations and results. As well as being a fascinating clinical phenomenon, the study of spatial neglect helps us tounderstand normal mechanisms of directing and maintaining spatial attention and is relevant to the contemporary search for the cerebral correlates of conscious experience, voluntary action and the nature of personal identity itself.The book is divided into seven sections covering the anatomical and neurophysiological bases of the disorder, frameworks of neglect, perceptual and motor factors, the relation to attention, the cognitive processes involved, and strategies for rehabilitation.Chapters have been written by a team of the leading international experts in this field.This will be essential reading for neuropsychologists, neurologists, neurophysiologists, cognitive neuroscientists and psychologists.
The Cognitive Neuroscience Of Attention
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Author : Joseph B. Hopfinger
language : en
Publisher: Routledge
Release Date : 2020-12-17
The Cognitive Neuroscience Of Attention written by Joseph B. Hopfinger and has been published by Routledge this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-12-17 with Psychology categories.
Attention refers to our ability to selectively process the vast array of stimuli impinging upon our senses at every moment. The mental processes of attention are critical for allowing us to maintain focus and complete tasks efficiently, even within distracting environments. The brain mechanisms of attention have been studied for decades, yet much still remains unknown, and consensus on core issues remains elusive. A unique aspect of this book are chapters that highlight recent debates on critical issues in attention research. Each of these chapters includes a comprehensive discussion paper that is followed by peer commentaries and an authors' responses. These debates include whether attention can modulate activity of even the earliest cortical processing region and whether changes in white matter are critical for plasticity-related effects of attention training. In addition to these discussion chapters, the book presents cutting-edge research on some of the newest theories of attentional control and selective attention, including the influence of practice, epigenetics, reward, social interaction, and distractor suppression. These studies employ advanced cognitive neuroscience methods such as neurostimulation, functional neuroimaging pattern analysis, and the evaluation of oscillatory brain activity to shed light on the brain mechanisms underlying attention. The chapters in this book were originally published as articles in various issues of the journal Cognitive Neuroscience.
Cortical Mechanisms Of Selective Attention To Spatial And Non Spatial Stimulus Features
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Author : Antigona Martinez-Quintero
language : en
Publisher:
Release Date : 1999
Cortical Mechanisms Of Selective Attention To Spatial And Non Spatial Stimulus Features written by Antigona Martinez-Quintero and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1999 with Neural circuitry categories.