Download or read book Electrophysiological Evidence of Interactive Object based and Space based Attention Mechanisms written by Pamela A. Burton and published by . This book was released on 2004 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physiological Evidence of Interactive Object based and Space based Attention Mechanisms written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Visual attention has been likened to a spotlight that enhances both attended and nearby objects. However, experiments employing overlapping stimuli have shown that individuals are able to attend selectively to one object while suppressing the other. These data are problematic for spotlight theories of selection, suggesting that under some circumstances, selection may also be made with respect to objects rather than spatial location. It has been suggested that these two types of selection are achieved by a single mechanism by which the attentional spotlight conforms to the boundary of an object. Alternatively, space- and object-based selection may be independent, but mutually supporting systems. The present set of experiments examined the relationship between object-based and space-based selection using event-related potentials (ERPs). Previous research has shown that attention to spatial location results in an enhancement of the P1 and N1 components of the ERP. This pattern is associated with spatial attention and is not seen when observers are attending to non-spatial attributes, such as color or shape. In the object-based attention condition, ERPs were collected in response to flashes on attended objects, unattended overlapping objects, and unattended objects at far locations. In the space-based attention condition, ERPs were elicited by the same flashes occurring in empty locations. Both space-based and object-based ERPs produced P1 and N1 components, but only the space-based ERPs showed an attentional effect on P1 amplitude. The attentional effect on the parietal N1 was nearly identical for both object- and space-based ERPS. These data suggest that space and object-based attention may be separate, but interactive systems.
Download or read book Cognitive Electrophysiology of Attention written by George R. Mangun and published by Academic Press. This book was released on 2013-08-31 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cognitive Electrophysiology of Attention explores the fundamental mechanisms of attention and related cognitive functions from cognitive neuroscience perspectives. Attention is an essential cognitive ability that enables humans to process and act upon relevant information while ignoring distracting information, and the capacity to focus attention is at the core of mental functioning. Understanding the neural bases of human attention remains a key challenge for neuroscientists and psychologists, and is essential for translational efforts to treat attentional deficits in a variety of neurological and psychiatric disorders. Cognitive electrophysiology is at the center of a multidisciplinary approach that involves the efforts of psychologists, neuroscientists, neuropsychologists, psychiatrists, and neurologists to identify basic brain mechanisms and develop translational approaches to improve mental health. This edited volume is authored by leading investigators in the field and discusses methods focused on electrophysiological recordings in humans, including electroencephalography (EEG) and event-related potential (ERP) methods, and also incorporates evidence from functional magnetic resonance imaging (fMRI). Cognitive Electrophysiology of Attention illuminates specific models about attentional mechanisms in vision, audition, multisensory integration, memory, and semantic processing in humans. Provides an exhaustive overview of attention processes, going from normal functioning to the pathological, and using a combination of methodological tools An important reference for electrophysiology researchers looking at underlying attention processes rather than the methods themselves Enables researchers across a broad range of cognitive-process and methodological specialties to stay current on particular hypotheses, findings, and methods Edited and authored by the worldwide leaders in the field, affording the broadest, most expert coverage available
Download or read book The Cognitive Electrophysiology of Mind and Brain written by Alberto Zani and published by Academic Press. This book was released on 2002-10-02 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: When his beloved donkey becomes ill, a young Italian boy is determined to take her to the crypt of St. Francis in Assisi in hopes of making her well.
Download or read book Electrophysiological Correlates of Object based Selective Attention written by Marla Raye Zinni and published by . This book was released on 2010 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: A visual stimulus may be selectively attended on the basis of its location in space, a specific feature, or as a whole object. While a relatively large amount of research has examined the neural basis of location-based and feature-based attentional selection, few studies have examined the neural correlates of the spread of attention from one feature of an object to another, reflecting the selection of an object as an "integrated feature ensemble" (Schoenfeld et al., 2003; O'Craven, Downing, & Kanwisher, 1999). The research in this dissertation examined the electrophysiological correlates of the spread of selective attention to a task-irrelevant color feature of an object using the event-related potential (ERP) brain imaging technique. The temporal dynamics of this spread of attention were examined for two classes of objects, grouped-arrays of lines (Study 1) and geometric shapes (Study 2). In each study, overlapping objects were presented and the participants' task was to sustain attention to one object versus another to judge a change in the thickness of one of the lines of the grid (Study 1) or a change in object shape (Study 2). On some trials, either the attended object or the unattended object was colored, and color was irrelevant to the task. Difference ERPs indicated that color was first encoded in the visual cortex by 100 ms. However, the effect of attention on the task-irrelevant color feature was evident in later ERP modulations. A bilateral parietal/occipital positivity beginning at 200 ms (Study 2) and a midline occipital negativity beginning at 280 ms (Studies 1 & 2) were associated with the selection of the irrelevant color of the attended object. Source localization analyses suggested that the neural generators of the attention-related facilitation of the irrelevant color feature were situated in ventral occipital cortical regions near color-selective cortical areas. These data provide further evidence for the "integrated competition" model (Duncan, 1996; 1997), which posits that the neural basis for the perceptual integration of an attended object consists of enhanced activity in the network of specialized modules that encode its individual features, including those that are not relevant to the immediate task.
Download or read book Shared Mechanisms of Object based Attention and Object Working Memory written by Lisa Laverne Barnes and published by . This book was released on 1996 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Noise to Characterize Vision written by Rémy Allard and published by Frontiers Media SA. This book was released on 2016-03-02 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Noise has been widely used to investigate the processing properties of various visual functions (e.g. detection, discrimination, attention, perceptual learning, averaging, crowding, face recognition), in various populations (e.g. older adults, amblyopes, migrainers, dyslexic children), using noise along various dimensions (e.g. pixel noise, orientation jitter, contrast jitter). The reason to use external noise is generally not to characterize visual processing in external noise per se, but rather to reveal how vision works in ordinary conditions when performance is limited by our intrinsic noise rather than externally added noise. For instance, reverse correlation aims at identifying the relevant information to perform a given task in noiseless conditions and measuring contrast thresholds in various noise levels can be used to understand the impact of intrinsic noise that limits sensitivity to noiseless stimuli. Why use noise? Since Fechner named it, psychophysics has always emphasized the systematic investigation of conditions that break vision. External noise raises threshold hugely and selectively. In hearing, Fletcher used noise in his famous critical-band experiments to reveal frequency-selective channels in hearing. Critical bands have been found in vision too. More generally, the big reliable effects of noise give important clues to how the system works. And simple models have been proposed to account for the effects of visual noise. As noise has been more widely used, questions have been raised about the simplifying assumptions that link the processing properties in noiseless conditions to measurements in external noise. For instance, it is usually assumed that the processing strategy (or mechanism) used to perform a task and its processing properties (e.g. filter tuning) are unaffected by the addition of external noise. Some have suggested that the processing properties could change with the addition of external noise (e.g. change in filter tuning or more lateral masking in noise), which would need to be considered before drawing conclusions about the processing properties in noiseless condition. Others have suggested that different processing properties (or mechanisms) could be solicited in low and high noise conditions, complicating the characterization of processing properties in noiseless condition based on processing properties identified in noise conditions. The current Research Topic probes further into what the effects of visual noise tell us about vision in ordinary conditions. Our Editorial gives an overview of the articles in this special issue.
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.
Download or read book Objects and Attention written by Brian J. Scholl and published by MIT Press. This book was released on 2002 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of object-based models of attention.
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
Download or read book Perception Cognition and Working Memory Interactions Technology and Applied Research written by Hong Xu and published by Frontiers Media SA. This book was released on 2023-04-04 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cumulated Index Medicus written by and published by . This book was released on 2000 with total page 1764 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrophysiological Investigation of Feature based Attention During Object Perception written by Boge Bobby Stojanoski and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Cognitive Neuroscience Society Annual Meeting Abstract Program written by Cognitive Neuroscience Society. Meeting and published by . This book was released on 2009 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Perceptual Organization written by Michael Kubovy and published by Routledge. This book was released on 2017-03-31 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in 1981, perceptual organization had been synonymous with Gestalt psychology, and Gestalt psychology had fallen into disrepute. In the heyday of Behaviorism, the few cognitive psychologists of the time pursued Gestalt phenomena. But in 1981, Cognitive Psychology was married to Information Processing. (Some would say that it was a marriage of convenience.) After the wedding, Cognitive Psychology had come to look like a theoretically wrinkled Behaviorism; very few of the mainstream topics of Cognitive Psychology made explicit contact with Gestalt phenomena. In the background, Cognition's first love – Gestalt – was pining to regain favor. The cognitive psychologists' desire for a phenomenological and intellectual interaction with Gestalt psychology did not manifest itself in their publications, but it did surface often enough at the Psychonomic Society meeting in 1976 for them to remark upon it in one of their conversations. This book, then, is the product of the editors’ curiosity about the status of ideas at the time, first proposed by Gestalt psychologists. For two days in November 1977, they held an exhilarating symposium that was attended by some 20 people, not all of whom are represented in this volume. At the end of our symposium it was agreed that they would try, in contributions to this volume, to convey the speculative and metatheoretical ground of their research in addition to the solid data and carefully wrought theories that are the figure of their research.
