Download or read book The Cortical Topography of Self motion Perception written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Sub cortical Contributions to Self motion Perception written by Alexis Paez and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Our ability to navigate the world around us requires that the brain maintain a representation of ongoing self-motion. In order for this to occur, vestibular sensory information about rotational and linear movement of the head in space is relayed via vestibular afferents in the VIIIth cranial nerve to the vestibular nuclei in the brainstem. From there, vestibular signals contribute to gaze and posture-stabilizing reflexes through projections to oculomotor neurons and the spinal cord, as well as to cortical processing of spatial orientation and perception of self-motion. Through recordings in rhesus monkey, the goal of my thesis work is to investigate the encoding of these signals in ascending vestibulo-thalamic pathways that contribute to self-motion perception.My first focus was the vestibular projection through the nucleus prepositus to the anterior thalamus. This pathway has been suggested as a potential relay for vestibular signals to the head direction network, which provides an estimate of spatial orientation. I demonstrate that this is not the case. Instead, burst-tonic neurons, which make up the vast majority of neurons in the nucleus prepositus, exhibit activity related to eye position and eye velocity, even during concurrent head motion. These results are consistent with the role of the nucleus prepositus as the velocity-to-position neural integrator providing premotor control for horizontal eye movements. To understand the mechanism by which the ensemble of burst-tonic neurons achieves encoding of eye position from eye velocity inputs, I next performed ipsilateral pairwise recordings in the nucleus prepositus. I observed that the responses of these premotor neurons were highly correlated; moreover, neuronal activities were synchronized to a level exceeding what would be predicted from their firing rates and eye position sensitivities. Interestingly, I observed the magnitude of the excess synchrony was both behaviorally and anatomically dependent, consistent with the effects of common inhibitory input from the contralateral nucleus prepositus targeting burst-tonic neurons within a confined area. Together, my findings provide new insights into the intrinsic circuitry of the nucleus prepositus, while highlighting predominant eye position encoding in a key component of the anterior vestibulo-thalamic pathway.The second focus of my thesis was the vestibular processing pathway through the posterior thalamus, particularly the ventral posterior lateral nucleus, which projects directly to widespread cortical areas. I first identified two populations of vestibular sensitive neurons based on their sensitivities to neck proprioception. I then found that both populations selectively respond to externally-generated self-motion, and with greater selectivity than their input neurons. These results reveal that the vestibular thalamus relays vestibular sensory information to cortex in a behaviorally dependent manner.Finally, I analyzed simultaneously recorded pairs of vestibular afferents and pairs of vestibular nuclei neurons to understand how target neurons in the vestibular thalamus might integrate their inputs. By measuring noise correlations, I demonstrated that the activities of pairs of vestibular neurons exhibit uncorrelated variability both in the resting state and in responses to passive and active head movements. Thus, the vestibulo-thalamic projections discussed here receive largely independent inputs from the vestibular nuclei. This, in turn, suggests that variability in sensory responses can be averaged away by neurons in the thalamus, leading to a more accurate representation of ongoing head motion. Taken together, the results of this PhD thesis provide new understanding of sensory processing in ascending vestibular pathways. My findings suggest the need to reevaluate the coding of vestibular information in higher-order centers, especially to address potential differences in processing across behavioral conditions." --
Download or read book Visual motion and self motion processing in the human brain MPI Series in Biological Cybernetics Bd 31 written by Elvira Fischer and published by Logos Verlag Berlin GmbH. This book was released on 2011 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the successful recognition of objective, `real' motion based on visual cues it is necessary to take self-induced motion signals into account, such as those induced by eye-movements. During a series of fMRI studies we measured responses of visual and parietal regions to motion cues derived from (a) retinal motion, (b) eyemovements (visual pursuit) and (c) objective, (real) motion. We show that the recently described cingulate sulcus visual area (CSv) is not, as implied before, primarily driven by 3D self-motion cues but favoured 2D translational coherent motion over 3D expanding flow fields. Further, we found that V3A is capable of integrating retinal motion with eye-movements, thus allowing V3A to respond to object motion independent of retinal motion. This allowed us to define a new functional localizer for area V3A. Finally, we showed that activity in the foveal representation of the early visual cortex is driven by a combination of retinal input and by error signals as hypothesized by of Rao and Ballard (1999) for predictive coding. Taken together, this work provides evidence that regions V3A and CSv are key regions concerning visual self-motion processing and that early visual regions might be modulated by feedback from higher motion processing regions.
Download or read book Handbook of Functional Neuroimaging of Cognition second edition written by Roberto Cabeza and published by MIT Press. This book was released on 2006-05-05 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new edition of the essential resource on using functional neuroimaging techniques to study the neural basis of cognition, revised with the student in mind; thoroughly updated, with new chapters on fMRI physics, skill learning, emotion and social cognition, and other topics. This essential resource on neuroimaging provides an accessible and user-friendly introduction to the field written by leading researchers. The book describes theoretical and methodological developments in the use of functional neuroimaging techniques to study the neural basis of cognition, from early scientific efforts to link brain and behavior to the latest applications of fMRI and PET methods. The core of the book covers fMRI and PET studies in specific domains: attention, skill learning, semantic memory, language, episodic memory, working memory, and executive functions. By introducing a technique within the description of a domain, the book offers a clear explanation of the process while highlighting its biological context. The emphasis on readability makes Handbook of Functional Neuroimaging of Cognition ideal for classroom use in advanced undergraduate and graduate courses in cognitive neuroscience. This second edition has been completely updated to reflect new developments in the field, with existing chapters rewritten and new chapters added to each section. The section on history and methods now includes a chapter on the crucial topic of the physics of functional neuroimaging; the chapters on skill learning and executive functions are new to the domain section; and chapters on childhood development and emotion and social cognition have been added to the section on developmental, social, and clinical applications. The color insert has been increased in size, enhancing the visual display of representative findings. Contributors Todd S. Braver, Jeffrey Browndyke, Roberto Cabeza, B.J. Casey, Jody Culham, Clayton E. Curtis, Mark D'Esposito, Sander Daselaar, Lila Davachi, Ian Dobbins, Karl J. Friston, Barry Giesbrecht, Todd C. Handy, Joseph B. Hopfinger, Scott A. Huettel, Irene P. Kan, Alan Kingstone, Eleni Kotsoni, Kevin S. LaBar, George R. Mangun, Gregory McCarthy, Uta Noppeney, Robyn T. Oliver, Elizabeth A. Phelps, Russel A. Poldrack, Cathy J. Price, Marcus E. Raichle, Hannes Ruge, Gaia Scerif, Allen W. Song, Sharon L. Thompson-Schill, Daniel T. Willingham, Richard J.S. Wise
Download or read book About Horizontal Self motion Perception written by Barbara Saskia Mesland and published by . This book was released on 1998 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Active Control of Self Movement Perception Neuronal Mechanisms and Cognitive Aging written by Michael Simon Jacob and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-movement creates a radial pattern of optic flow that tells us where we are going. Recent studies have shown that the processing of visual motion is actively controlled by frontal-parietal cortical networks to satisfy the demands of ongoing behavior. Navigation-related visual motion perceptual deficits in aging and Alzheimer's disease (AD) suggest a systems level disruption of optic flow processing in these conditions. We have now examined this system using human evoked potentials and probed the underlying neuronal mechanisms using monkey single neuron physiology. In our studies of aging and AD, we combine a continuous visual discrimination task with simultaneous visual motion and word stimulus streams to assess task effects on stimulus evoked cortical activity. We find that the cognitive control of motion and word processing are fundamentally different in aging and AD. Impairments in verbal fluency among our AD patients and impairments in optic flow perceptual thresholds among our older adult subjects are associated with selective reductions in cortical responsiveness to word and optic flow stimuli, respectively. Thus, diagnostic criteria for AD may not appropriately consider impairments in visuospatial processing. Monkeys trained in a memory guided steering task show single neurons with task-dependent optic flow processing in cortical areas MST and LIP. One third of MST neurons show task effects on basic neuronal response properties. In contrast, LIP neurons show minimal optic flow stimulus selectivity but pronounced task effects on their responses. Both MST and LIP show evidence of cognitive signals related to motor planning just prior to steering. These results suggest that posterior parietal cortical areas form a distributed network which is dynamically shaped by task demands. Despite species and methodological differences, the dynamics of cortical activity in humans and monkeys show sensory signals that are followed shortly by cognitive signals to actively modulate self-movement perception. In young adult human subjects and monkey single neurons, we see obligate optic flow processing in all task conditions. In older adult humans, we see a loss of obligate optic flow responsiveness which may suggest a selective vulnerability of visuospatial processing networks in cognitive aging.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 1997 with total page 1860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Perception of Self Motion written by Alessandro Nesti and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Everyday life requires humans to move through the environment, while completing crucial tasks such as retrieving nourishment, avoiding perils or controlling motor vehicles. Success in these tasks largely relies in a correct perception of self-motion, i.e. the continuous estimation of one's body position and its derivatives with respect to the world. The processes underlying self-motion perception have fascinated neuroscientists for more than a century and large bodies of neural, behavioural and physiological studies have been conducted to discover how the central nervous system integrates available sensory information to create an internal representation of the physical motion. The goal of this PhD thesis is to extend current knowledge on self-motion perception by focusing on conditions that closely resemble typical aspects of everyday life. In the works conducted within this thesis, I isolate different components typical of everyday life motion and employ psychophysical methodologies to systematically investigate their effect on human self-motion sensitivity. Particular attention is dedicated to the human ability to discriminate between motions of different intensity. How this is achieved has been a fundamental question in the study of perception since the seminal works of Weber and Fechner. When tested over wide ranges of rotations and translations, participants' sensitivity (i.e. their ability to detect motion changes) is found to decrease with increasing motion intensities, revealing a nonlinearity in the perception of self-motion that is not present at the level of ocular reflexes or in neural responses of sensory afferents. The relationship between the stimulus intensity and the smallest intensity change perceivable by the participants can be mathematically described by a power law, regardless on the sensory modality investigated (visual or inertial) and on whether visual and inertial cues were presented alone or congruently combined, such as during natural movements. Individual perceptual law parameters were fit based on experimental data for upward and downward translations and yaw rotations based on visual-only, inertial-only and combined visual-inertial motion cues. Besides wide ranges of motion intensities, everyday life scenarios also provide complex motion patterns involving combinations of rotational and translational motion, visual and inertial sensory cues and physical and mental workload. The question of how different combinations of these factors affect motion sensitivity was experimentally addressed within the framework of driving simulation and revealed that sensitivity might strongly decrease in more realistic conditions, where participants do not only focus on perceiving a 'simple' motion stimulus (e.g. a sinusoidal profile at a specific frequency) but are, instead, actively engaged in a dynamic driving simulation. Applied benefits of the present thesis include advances in the field of vehicle motion simulation, where knowledge on human self-motion perception supports the development of state-of-the-art algorithms to control simulator motion. This allows for reproducing, within a safe and controlled environment, driving or flying experiences that are perceptually realistic to the user. Furthermore, the present work will guide future research into the neural basis of perception and action.
Download or read book Sensation of Movement written by Thor Grünbaum and published by Routledge. This book was released on 2017-09-14 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensation of Movement explores the role of sensation in motor control, bodily self-recognition and sense of agency. The sensation of movement is dependent on a range of information received by the brain, from signalling in the peripheral sensory organs to the establishment of higher order goals. Through the integration of neuroscientific knowledge with psychological and philosophical perspectives, this book questions whether one type of information is more relevant for the ability to sense and control movement. Addressing conscious sensations of movement, experimental designs and measures, and the possible functions of proprioceptive and kinaesthetic information in motor control and bodily cognition, the book advocates the integration of neuroscientific knowledge and philosophical perspectives. With an awareness of the diverse ideas and theories from these distinct fields, the book brings together leading researchers to bridge these divides and lay the groundwork for future research. Of interest to both students and researchers of consciousness, Sensation of Movement will be essential reading for those researching motor control, multimodal perception, bodily self-recognition, and sense of agency. It aims to encourage the integration of multiple perspectives in order to arrive at new insights into how sensation of movement can be studied scientifically.
Download or read book Visual Cortical Mechanisms of Motion Perception and Navigation written by Christopher Pack and published by . This book was released on 1999 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visual Mismatch Negativity vMMN a Prediction Error Signal in the Visual Modality written by Gabor Stefanics and published by Frontiers Media SA. This book was released on 2015-06-04 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current theories of visual change detection emphasize the importance of conscious attention to detect unexpected changes in the visual environment. However, an increasing body of studies shows that the human brain is capable of detecting even small visual changes, especially if such changes violate non-conscious probabilistic expectations based on repeating experiences. In other words, our brain automatically represents statistical regularities of our visual environmental. Since the discovery of the auditory mismatch negativity (MMN) event-related potential (ERP) component, the majority of research in the field has focused on auditory deviance detection. Such automatic change detection mechanisms operate in the visual modality too, as indicated by the visual mismatch negativity (vMMN) brain potential to rare changes. VMMN is typically elicited by stimuli with infrequent (deviant) features embedded in a stream of frequent (standard) stimuli, outside the focus of attention. In this research topic we aim to present vMMN as a prediction error signal. Predictive coding theories account for phenomena such as mismatch negativity and repetition suppression, and place them in a broader context of a general theory of cortical responses. A wide range of vMMN studies has been presented in this Research Topic. Twelve articles address roughly four general sub-themes including attention, language, face processing, and psychiatric disorders. Additionally, four articles focused on particular subjects such as the oblique effect, object formation, and development and time-frequency analysis of vMMN. Furthermore, a review paper presented vMMN in a hierarchical predictive coding framework. Each paper in this Research Topic is a valuable contribution to the field of automatic visual change detection and deepens our understanding of the short term plasticity underlying predictive processes of visual perceptual learning.
Download or read book Neuro ophthalmology written by Christopher Kennard and published by Elsevier. This book was released on 2011-06-28 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Clinical Neurology Vol 102: Neuro-Ophthalmology provides a comprehensive discussion of the field of neuro-ophthalmology. The book is organized into four sections. Section 1 lays out fundamental concepts of the visual system and eye movements. It discusses the anatomy and physiology of the afferent visual system and the ocular motor system, and the neuro-ophthalmological examination. Section 2 deals with disorders of the afferent visual system, covering retinal disorders; abnormalities of the optic disc; lesions of the optic nerve; the optic chiasm; disorders of the optic tract, radiation, and occipital lobe; disorders of higher visual processing; and rehabilitative techniques. Section 3 discusses ocular motor abnormalities, including infranuclear ocular motor disorders; nuclear, internuclear, and supranuclear ocular motor disorders; nystagmus and saccadic intrusions; disorders of higher gaze control; and normal and abnormal lid function. Section 4 covers disorders of the pupil; neuro-ophthalmology of orbital disease; and functional neuro-ophthalmology. This book will be useful to early-stage physicians, as well as specialists interested in the latest developments in neuro-ophthalmology. - A comprehensive resource that explores the innovative methods used to understand the visual system - An in-depth study of how the brain processes vision, and the role certain functions such as eye movement play in visual diagnosis and memory - Clinical and laboratory methods of evaluation that are perfect for physicians and specialists in any stage of practice
Download or read book Physiological Correlates of Visually Induced Self motion Perception written by Kai Volker Thilo and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self motion Perception Through Visual Optic Flow and Vestibular Cues written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self motion Perception Through Visual Optic Flow and Vestibular Cues written by Daniel Christopher Zikovitz and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self motion Perception from Optic Flow and Rotation Signals written by Jakob Andries Beintema and published by . This book was released on 2000 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Human Self motion Perception During Vertical Linear Oscillation and Virtual Environment Exposure written by William Geoffrey Wright and published by . This book was released on 2002 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
