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Investigating Mechanisms Of Spatial And Temporal Selective Visual Attention
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Book Synopsis Investigating Mechanisms of Spatial and Temporal Selective Visual Attention by : Mary E. Smith
Download or read book Investigating Mechanisms of Spatial and Temporal Selective Visual Attention written by Mary E. Smith and published by . This book was released on 2017 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selective attention in vision undoubtedly uses many different types of mechanisms to achieve better processing of behaviorally relevant visual information. The present dissertation inspects two such possible mechanisms. The first proposed mechanism is through selective spatial attention. We proposed that "attentional control" regions of the brain send selective attention signals that relate to the differential attentional modulation measured in visual cortex, corresponding to the attended and ignored sides of visual space. We find, surprisingly, that the BOLD signal of attentional control regions do not appear to code for selective spatial attention in this manner. fMRI signals therefore appear to prioritize general arousal effects of attention more so than the types of attentional control signals that frontoparietal regions send to early visual cortex. The second proposed mechanism is through sampling visual information through time. It is hypothesized that intrinsic neural oscillations represent inhibitory waves of cortical processing ability, in which subjects are more or less able to detect visual stimuli depending on the phase of [alpha] oscillations in the brain. We used a paradigm involving visual entrainment; this paradigm has been used in the past to support the "pulsed inhibition of [alpha]" hypothesis. We find that the behavioral effects of this paradigm cannot strongly be supported by the pulsed inhibition of [alpha] because the neural effects of visual entrainment are transient and do not carry over into the target period.
Book Synopsis Encyclopedia of Neuroscience by : Marc D. Binder
Download or read book Encyclopedia of Neuroscience written by Marc D. Binder and published by Springer. This book was released on 2008-10-13 with total page 4398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 5000-page masterwork is literally the last word on the topic and will be an essential resource for many. Unique in its breadth and detail, this encyclopedia offers a comprehensive and highly readable guide to a complex and fast-expanding field. The five-volume reference work gathers more than 10,000 entries, including in-depth essays by internationally known experts, and short keynotes explaining essential terms and phrases. In addition, expert editors contribute detailed introductory chapters to each of 43 topic fields ranging from the fundamentals of neuroscience to fascinating developments in the new, inter-disciplinary fields of Computational Neuroscience and Neurophilosophy. Some 1,000 multi-color illustrations enhance and expand the writings.
Book Synopsis An Investigation of the Development of Selective Visual Attention by : Emily Rachel Owen
Download or read book An Investigation of the Development of Selective Visual Attention written by Emily Rachel Owen and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the knowledge of one's surroundings comes from vision, especially in infancy. As much of what we first learn is by way of visual processing, it is essential that infants be able to select only relevant information from the crowded visual environment. Indeed, the developmental literature suggests that attentional orienting and object indexing are key processes of selective attention, requisite for higher-level information processing. Research further shows that dynamic selective attention depends on the detection of spatiotemporal cues in the environment, and that this kind of visual attention is supported by parietal cortex. Fragile X syndrome is a neurodevelopmental disorder associated with a single-gene mutation, and represents a leading hereditary cause of intellectual impairment. Selective visual processing deficits are hallmark cognitive features in infants with FXS, as are parietally-mediated impairments in adults; however, the developmental link between early visual attention deficits and later domain-specific cognitive deficits remains poorly understood. This dissertation presents findings from a novel program of visual eye-tracking experiments conducted in both typical infants and a population of young children with FXS. Three separate studies investigated selective attention processes across different cognitive domains (attention orienting, numerical processing, and sequence processing). The inclusive FXS-group performance across all three studies showed that, in this sample, impaired orienting was associated with the failure to use selective attention to extract the numerical and ordinal information from multiple element displays. These results support the hypothesis that impaired mechanisms of parietally-mediated integration of spatiotemporal information may be a fundamental source of abnormal cognitive outcome in FXS.
Book Synopsis Selective Visual Attention. An Experimental Investigation on the Effects of Spatial Distance in Whole Report Tasks by : Christian Valla
Download or read book Selective Visual Attention. An Experimental Investigation on the Effects of Spatial Distance in Whole Report Tasks written by Christian Valla and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Neural Mechanisms of Spatial Attention by : Ashley Royston
Download or read book Neural Mechanisms of Spatial Attention written by Ashley Royston and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Spatial, Feature and Temporal Attentional Mechanisms in Visual Motion Processing by :
Download or read book Spatial, Feature and Temporal Attentional Mechanisms in Visual Motion Processing written by and published by . This book was released on 2012 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three projects documented in this thesis investigated the role of three forms of attention in visual processing. Spatial, feature-based and temporal attention. The spatial and feature-based attentional characteristics were studied by conducting extracellular recordings from neurons of area MT and MSTd of macaque visual cortex. While the role of temporal attention was studied in a human psychophysics project. In the physiology projects we first defined the tuning characteristics of neurons from area MT and MSTd for two stimulus dimensions, namely spiral motion stimuli (SMS) and linear mo...
Book Synopsis Spatial and Temporal Distribution of Visual Attention by : Alicia MacKay
Download or read book Spatial and Temporal Distribution of Visual Attention written by Alicia MacKay and published by . This book was released on 2005 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Attention, Space, and Action by : Glyn W. Humphreys
Download or read book Attention, Space, and Action written by Glyn W. Humphreys and published by Oxford University Press, USA. This book was released on 1999 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: To generate coherent behavior, the brain needs to attend selectively to the many objects that are present in the environment, but this poses several questions. How does the brain know which objects 'belong together'? How does the information from different senses get combined? How does this help to plan and carry out actions? The subject of attentional mechanisms has a long history in cognitive psychology, as it is the key to making sense of the visual world. However, new developments in cognitive neuroscience, and greater understanding of how attention and action are integrated, have transformed the field. This book is the first to bring together leading researchers to discuss the convergence of experimental findings in the following areas: visual selective attention, attention and perceptual integration, spatial representation and attention, visual attention and action, and control of attention. Attention, Space, and Action provides a unique combination of perspectives that will appeal to students and researchers from psychology, neuropsychology, neurophysiology, and neuroanatomy.
Book Synopsis Studying Feature Specific Mechanisms of the Human Visual System by : C. E. Kaul
Download or read book Studying Feature Specific Mechanisms of the Human Visual System written by C. E. Kaul and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: What are the current limits of our knowledge of brain activity underlying vision and can I further this knowledge? In this thesis, I explore this basic question. I focus on those aspects of visual input that can be described as basic features of visual perception. Examples include orientation, color, direction of motion and spatial frequency. However, understanding how humans visually perceive the external world is closely related with the study of attention. Attention, that is, the selection of some aspects of the environment over others, is one of the most intensively studied areas in experimental psychology, yet its neural mechanisms remain largely elusive. This thesis focuses on three distinct topics at the border of feature specific visual perception and feature-specific visual attention. First, in a series of studies, I explore the influence of heightened attentional demand to a central task to feature-specific neural processing in the ignored periphery. I discover that heightened attentional demand does not influence feature-specific representations in early visual cortices. Second, I investigate the influence of feature-based attention on neural processing of early visual cortices. At the same time, I also probe the influence of a behavioral decision to deploy feature-specific attention in the imminent future. I find that feature-based attention operates independent of other types of attention. Additionally, results indicate that a behavioral decision to deploy feature-based attention alone, without visual stimulation present, is able to modulate neural activity in early visual cortices. Third, I examine the more complex feature of facial gender and where in the brain gender discrimination might receive neural processing. I find that, in an established network of face-selective brain areas, facial gender is represented in nearly all areas of that network. Finally, I discuss all findings in the light of the current state of research, for their scientific significance and for future research opportunities.
Book Synopsis Tracking Attention in Space and Time by :
Download or read book Tracking Attention in Space and Time written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Attention is essential to everyday life: without some selective function to guide and limit the processing of incoming information, our visual system would be overwhelmed. A description of the spatiotemporal dynamics of attention is critical to our understanding of this basic human cognitive function and is the primary goal of this dissertation. In particular, the research reported here is aimed at examining two aspects of the spatiotemporal dynamics of attention: a) the rate at which the focus of attention is shrunk and expanded along with the factors that influence this rate, and b) the factors governing whether attention is deployed as either a unitary or a divided focus. The present research examines the spatiotemporal dynamics of focal attention by monitoring the pattern of accuracy that occurs when participants attempt to identify two targets embedded in simultaneously presented streams of items. By asking participants to monitor these streams simultaneously, with the spatial and temporal positions of the two targets in the streams being varied incrementally, it is possible to index the extent of focal attention in both space and time. Chapter 2 develops this behavioural procedure and assesses the rate at which the focus of attention is contracted. A qualitative model is put forward and tested. Chapter 3 examines factors that modulate the temporal course of attentional narrowing in young adults who presumably can exercise efficient control of attentional processes. In contrast, Chapter 4 examines the effect of reduced attentional control by examining the same process in older adults. The second goal of this thesis was to examine whether focal attention is deployed as a unitary or a divided focus. These two perspectives are generally viewed as mutually exclusive. The alternative hypothesis pursued in Chapter 5 is that focal attention can be deployed as either a single, unitary focus or divided into multiple foci, depending on the observers mental set and on the.
Download or read book Attention written by Addie Johnson and published by SAGE. This book was released on 2004 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Attention: Theory and Practice provides a balance between a readable overview of attention and an emphasis on how theories and paradigms for the study of attention have developed. The book highlights the important issues and major findings while giving sufficient details of experimental studies, models, and theories so that results and conclusions are easy to follow and evaluate. Rather than brushing over tricky technical details, the authors explain them clearly, giving readers the benefit of understanding the motivation for and techniques of the experiments in order to allow readers to think through results, models, and theories for themselves. Attention is an accessible text for advanced undergraduate and graduate students in psychology, as well as an important resource for researchers and practitioners interested in gaining an overview of the field of attention.
Book Synopsis The Oxford Handbook of Attention by : Kia Nobre
Download or read book The Oxford Handbook of Attention written by Kia Nobre and published by Oxford University Press. This book was released on 2018 with total page 1260 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Neurobiology of Attention by : Laurent Itti
Download or read book Neurobiology of Attention written by Laurent Itti and published by Elsevier. This book was released on 2005-03-31 with total page 757 pages. Available in PDF, EPUB and Kindle. Book excerpt: A key property of neural processing in higher mammals is the ability to focus resources by selectively directing attention to relevant perceptions, thoughts or actions. Research into attention has grown rapidly over the past two decades, as new techniques have become available to study higher brain function in humans, non-human primates, and other mammals. Neurobiology of Attention is the first encyclopedic volume to summarize the latest developments in attention research.An authoritative collection of over 100 chapters organized into thematic sections provides both broad coverage and access to focused, up-to-date research findings. This book presents a state-of-the-art multidisciplinary perspective on psychological, physiological and computational approaches to understanding the neurobiology of attention. Ideal for students, as a reference handbook or for rapid browsing, the book has a wide appeal to anybody interested in attention research. * Contains numerous quick-reference articles covering the breadth of investigation into the subject of attention* Provides extensive introductory commentary to orient and guide the reader* Includes the most recent research results in this field of study
Book Synopsis Attention, Voluntary Contraction, and Event-related Cerebral Potentials by : John E. Desmedt
Download or read book Attention, Voluntary Contraction, and Event-related Cerebral Potentials written by John E. Desmedt and published by S. Karger AG (Switzerland). This book was released on 1977 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Attention and Performance XIV by : David E. Meyer
Download or read book Attention and Performance XIV written by David E. Meyer and published by MIT Press. This book was released on 1993 with total page 956 pages. Available in PDF, EPUB and Kindle. Book excerpt: Attention and Performance XIV, provides a broad, historic, and timely synthesis of the empirical and theoretical ideas on which performance theory now rests.
Book Synopsis Attentional Capture by : Bradley S. Gibson
Download or read book Attentional Capture written by Bradley S. Gibson and published by . This book was released on 2008 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The notion that certain mental or physical events can capture attention has been one of the most enduring topics in the study of attention owing to the importance of understanding how goal-directed and stimulus-driven processes interact in perception and cognition. Despite the clear theoretical and applied importance of attentional capture, a broad survey of this field suggests that the term "capture" means different things to different people. In some cases, it refers to covert shifts of spatial attention, in others involuntary saccades, and in still others general disruption of processing by irrelevant stimuli. The properties that elicit "capture" can also range from abruptly onset or moving lights, to discontinuities in textures, to unexpected tones, to emotionally valenced words or pictures, to directional signs and symbols. Attentional capture has been explored in both the spatial and temporal domains as well as the visual and auditory modalities. There are also a number of different theoretical perspectives on the mechanisms underlying "capture" (both functional and neurophysiological) and the level of cognitive control over capture. This special issue provides a sampling of the diversity of approaches, domains, and theoretical perspectives that currently exist in the study of attentional capture. Together, these contributions should help evaluate the degree to which attentional capture represents a unitary construct that reflects fundamental theoretical principles and mechanisms of the mind.
Book Synopsis Spatial Biases in Perception and Cognition by : Timothy L. Hubbard
Download or read book Spatial Biases in Perception and Cognition written by Timothy L. Hubbard and published by Cambridge University Press. This book was released on 2018-08-23 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous spatial biases influence navigation, interactions, and preferences in our environment. This volume considers their influences on perception and memory.
