Download or read book Binaural Responses Underlay the Function of Primary Auditory Cortex written by Kyle Tokuichi Nakamoto and published by . This book was released on 2005 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of Responses Evoked in the Auditory Cortex of the Cat by Binaural Tonal Stimuli written by Judith Elaine Hirsch and published by . This book was released on 1968 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Functional Organization of Binaural and Temporal Processing in Primary Auditory Cortex of the Awake Monkey written by David Henry Reser and published by . This book was released on 1999 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coding of Sound Motion in the Rat Auditory Cortex written by Daryl Ebling Doan and published by . This book was released on 1997 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Auditory Evoked Responses Elicited by Binaural and Monaural Pure Tone Stimuli written by Jacqueline Robyn Dzau and published by . This book was released on 2002 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Binaural Hearing written by Ruth Y. Litovsky and published by Springer Nature. This book was released on 2021-03-01 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of Binaural Hearing involves studies of auditory perception, physiology, and modeling, including normal and abnormal aspects of the system. Binaural processes involved in both sound localization and speech unmasking have gained a broader interest and have received growing attention in the published literature. The field has undergone some significant changes. There is now a much richer understanding of the many aspects that comprising binaural processing, its role in development, and in success and limitations of hearing-aid and cochlear-implant users. The goal of this volume is to provide an up-to-date reference on the developments and novel ideas in the field of binaural hearing. The primary readership for the volume is expected to be academic specialists in the diverse fields that connect with psychoacoustics, neuroscience, engineering, psychology, audiology, and cochlear implants. This volume will serve as an important resource by way of introduction to the field, in particular for graduate students, postdoctoral scholars, the faculty who train them and clinicians.

Download or read book Plasticity of the Auditory System written by Thomas N. Parks and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The auditory system has a remarkable ability to adjust to an ever-changing environment. The six review chapters that comprise Plasticity of the Central Auditory System cover a spectrum of issues concerning this ability to adapt, defined by the widely applicable term "plasticity". With chapters focusing on the development of the cochlear nucleus, the mammalian superior olivary complex, plasticity in binaural hearing, plasticity in the auditory cortex, neural plasticity in bird songs, and plasticity in the insect auditory system, this volume represents much of the most current research in this field. The volume is thorough enough to stand alone, but is closely related a previous SHAR volume, Development of the Auditory System (Volume 9) by Rubel, Popper, and Fay. The book fully addresses the difficulties, challenges, and complexities of this topic as it applies to the auditory development of a wide variety of species.

Download or read book Binaural and Spatial Hearing in Real and Virtual Environments written by Robert Gilkey and published by Psychology Press. This book was released on 2014-02-25 with total page 1109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current popular and scientific interest in virtual environments has provided a new impetus for investigating binaural and spatial hearing. However, the many intriguing phenomena of spatial hearing have long made it an exciting area of scientific inquiry. Psychophysical and physiological investigations of spatial hearing seem to be converging on common explanations of underlying mechanisms. These understandings have in turn been incorporated into sophisticated yet mathematically tractable models of binaural interaction. Thus, binaural and spatial hearing is one of the few areas in which professionals are soon likely to find adequate physiological explanations of complex psychological phenomena that can be reasonably and usefully approximated by mathematical and physical models. This volume grew out of the Conference on Binaural and Spatial Hearing, a four-day event held at Wright-Patterson Air Force Base in response to rapid developments in binaural and spatial hearing research and technology. Meant to be more than just a proceedings, it presents chapters that are longer than typical proceedings papers and contain considerably more review material, including extensive bibliographies in many cases. Arranged into topical sections, the chapters represent major thrusts in the recent literature. The authors of the first chapter in each section have been encouraged to take a broad perspective and review the current state of literature. Subsequent chapters in each section tend to be somewhat more narrowly focused, and often emphasize the authors' own work. Thus, each section provides overview, background, and current research on a particular topic. This book is significant in that it reviews the important work during the past 10 to 15 years, and provides greater breadth and depth than most of the previous works.

Download or read book Plasticity in auditory cortex on the grounds of learning discrimination written by Hans Menning and published by GRIN Verlag. This book was released on 2005-01-19 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2002 in the subject Psychology - Biological Psychology, grade: magna cum laude, University of Münster (Institute for Experimental Audiology), language: English, abstract: The motivation for this thesis came from the intriguing idea that we continuously restructure our brain through everyday learning. How can this highly complex, highly adaptive “learning device” change and reorganize itself all the time while keeping the illusion that we are constantly “ourselves”? The question is, whether learning has the power to trigger functional and structural changes in the brain. Several levels of thinking are involved in an interdisciplinary way. Thus, on a psychological level, 3 major topics enter this work: learning, memory and preconscious or pre-attentive perception and processing of information. Pre-attentive perception means that the subjects' attention and awareness is not mirrored in the neuronal response at a great deal. Learning is involved in this study as an improving discrimination of fine frequency and word duration differences; the latter was examined in a group of native and non-native speakers. Memory is referred to as sensory memory, a short-time memory trace that is established through the repetition of the same “standard” stimulus. In the auditory modality this has been termed “echoic memory”. A long, repetitive training engraves deep “traces” into the memory. The lifelong training of one’s native language results in a very fast and highly automated long-term memory access. On a neurophysiological level the main topics are plasticity and the reorganization of the underlying representational brain areas. Plastic changes on a molecular, synaptic and neuronal level and reorganization of cortical “maps” have been demonstrated abundantly in animal studies. On a physical level the measured magnetic fields and the calculation of the source parameters of their underlying neural generators are discussed in the light of the neurophysiological and psychological phenomena. Therefore, the aim of this dissertation thesis was, to transfer the insights of animal plasticity research onto the human brain and to draw a connection line between discrimination learning and the underlying neurophysiological changes. In a second step, these effects of discrimination learning are tested on speech perception.

Download or read book The Technology of Binaural Understanding written by Jens Blauert and published by Springer Nature. This book was released on 2020-08-12 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sound, devoid of meaning, would not matter to us. It is the information sound conveys that helps the brain to understand its environment. Sound and its underlying meaning are always associated with time and space. There is no sound without spatial properties, and the brain always organizes this information within a temporal–spatial framework. This book is devoted to understanding the importance of meaning for spatial and related further aspects of hearing, including cross-modal inference. People, when exposed to acoustic stimuli, do not react directly to what they hear but rather to what they hear means to them. This semiotic maxim may not always apply, for instance, when the reactions are reflexive. But, where it does apply, it poses a major challenge to the builders of models of the auditory system. Take, for example, an auditory model that is meant to be implemented on a robotic agent for autonomous search-&-rescue actions. Or think of a system that can perform judgments on the sound quality of multimedia-reproduction systems. It becomes immediately clear that such a system needs • Cognitive capabilities, including substantial inherent knowledge • The ability to integrate information across different sensory modalities To realize these functions, the auditory system provides a pair of sensory organs, the two ears, and the means to perform adequate preprocessing of the signals provided by the ears. This is realized in the subcortical parts of the auditory system. In the title of a prior book, the term Binaural Listening is used to indicate a focus on sub-cortical functions. Psychoacoustics and auditory signal processing contribute substantially to this area. The preprocessed signals are then forwarded to the cortical parts of the auditory system where, among other things, recognition, classification, localization, scene analysis, assignment of meaning, quality assessment, and action planning take place. Also, information from different sensory modalities is integrated at this level. Between sub-cortical and cortical regions of the auditory system, numerous feedback loops exist that ultimately support the high complexity and plasticity of the auditory system. The current book concentrates on these cognitive functions. Instead of processing signals, processing symbols is now the predominant modeling task. Substantial contributions to the field draw upon the knowledge acquired by cognitive psychology. The keyword Binaural Understanding in the book title characterizes this shift. Both books, The Technology of Binaural Listening and the current one, have been stimulated and supported by AABBA, an open research group devoted to the development and application of models of binaural hearing. The current book is dedicated to technologies that help explain, facilitate, apply, and support various aspects of binaural understanding. It is organized into five parts, each containing three to six chapters in order to provide a comprehensive overview of this emerging area. Each chapter was thoroughly reviewed by at least two anonymous, external experts. The first part deals with the psychophysical and physiological effects of Forming and Interpreting Aural Objects as well as the underlying models. The fundamental concepts of reflexive and reflective auditory feedback are introduced. Mechanisms of binaural attention and attention switching are covered—as well as how auditory Gestalt rules facilitate binaural understanding. A general blackboard architecture is introduced as an example of how machines can learn to form and interpret aural objects to simulate human cognitive listening. The second part, Configuring and Understanding Aural Space, focuses on the human understanding of complex three-dimensional environments—covering the psychological and biological fundamentals of auditory space formation. This part further addresses the human mechanisms used to process information and interact in complex reverberant environments, such as concert halls and forests, and additionally examines how the auditory system can learn to understand and adapt to these environments. The third part is dedicated to Processing Cross-Modal Inference and highlights the fundamental human mechanisms used to integrate auditory cues with cues from other modalities to localize and form perceptual objects. This part also provides a general framework for understanding how complex multimodal scenes can be simulated and rendered. The fourth part, Evaluating Aural-scene Quality and Speech Understanding, focuses on the object-forming aspects of binaural listening and understanding. It addresses cognitive mechanisms involved in both the understanding of speech and the processing of nonverbal information such as Sound Quality and Quality-of- Experience. The aesthetic judgment of rooms is also discussed in this context. Models that simulate underlying human processes and performance are covered in addition to techniques for rendering virtual environments that can then be used to test these models. The fifth part deals with the Application of Cognitive Mechanisms to Audio Technology. It highlights how cognitive mechanisms can be utilized to create spatial auditory illusions using binaural and other 3D-audio technologies. Further, it covers how cognitive binaural technologies can be applied to improve human performance in auditory displays and to develop new auditory technologies for interactive robots. The book concludes with the application of cognitive binaural technologies to the next generation of hearing aids.

Download or read book Modulation and Manipulation of Sound Representation in the Auditory Cortex written by Jessica Liberty Sackville Hamilton and published by . This book was released on 2013 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain contains neurons of many different types interacting in complex functional circuits. To process sensory information these cells work in concert to form representations of the external world. In the auditory cortex, this involves integrating information from different cell types across an orderly anatomical structure of layers and columns. Representations can be observed at the level of single cells, cortical microcircuits, and large-scale sensory maps. The relationship between single cell properties and circuits within the auditory cortex, however, is still poorly understood. Furthermore, the structure-function relationships uncovered by neuroscientific study may crucially depend on the stimuli used to probe the system. This thesis brings together work from each of these different levels to describe how sounds are represented in the cortex, how this representation changes with experience, and how different cells contribute to cortical representation. First, I describe how the statistics of sound stimuli influence response properties in the mouse primary auditory cortex by comparing responses to pure tones and natural sounds (ultrasonic vocalizations). I also compare these responses to a temporally reversed vocalization to determine whether a sound with similar spectrotemporal content but no ethological relevance is represented similarly. When comparing pure tones and vocalizations, I find that the temporal response properties are similar, but that spectral response properties (e.g. frequency selectivity) often differ substantially. In particular, there are multiple sites that responded to vocalizations with frequency content outside their classical tone-derived receptive field, suggesting some specificity for behaviorally relevant sounds. When comparing forward and backward vocalizations, temporal responses are similar, but frequency bandwidth and characteristic frequency differs significantly across the population. Thus, the behaviorally relevant sound appears to be represented differently from non-behaviorally relevant synthetic and naturalistic sounds. The response properties of auditory neurons are not fixed, but rather depend on experience. In the next study, I examine how exposure to pulsed noise during different sensitive windows of the auditory critical period affects single site properties as well as circuit-level dynamics. On the single site level, I find that early exposure to pulsed noise increases receptive field thresholds and decreases frequency selectivity, while late noise exposure increases frequency bandwidths as well as spontaneous and evoked firing rates. To describe changes in functional microcircuits, I use the Ising model, which describes pairwise interactions between simultaneously recorded sites in the auditory cortex as well as interactions between sites and the stimuli that modulate them. I find that early noise exposure decreases stimulus drive, whereas late noise exposure does not change the strength of sound inputs but rather decreases the spread of functional connections from the deep to the superficial layers across sites with different frequency selectivity. Finally, I use a combination of optogenetic tools and computational methods to describe how the activity of a specific class of inhibitory neurons affects network connectivity in the auditory cortex. I examine the contribution of parvalbumin-positive (PV+) inhibitory interneurons, which make up around half of the inhibitory neurons in the cortex. These neurons are known to be involved in the generation of gamma oscillations, and their maturation corresponds with the end of the auditory critical period for plasticity. Using Ising models in tandem with linear-nonlinear vector autoregressive models, I show that stimulating PV+ neurons increases feedforward information flow through cortical circuits without changing lateral interactions within the same layers.

Download or read book Cortical and Subcortical Mechanisms for Sound Processing written by Jennifer M. Blackwell and published by . This book was released on 2019 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The auditory cortex is essential for encoding complex and behaviorally relevant sounds. Many questions remain concerning whether and how distinct cortical neuronal subtypes shape and encode both simple and complex sound properties. In chapter 2, we tested how neurons in the auditory cortex encode water-like sounds perceived as natural by human listeners, but that we could precisely parametrize. The stimuli exhibit scale-invariant statistics, specifically temporal modulation within spectral bands scaled with the center frequency of the band. We used chronically implanted tetrodes to record neuronal spiking in rat primary auditory cortex during exposure to our custom stimuli at different rates and cycle-decay constants. We found that, although neurons exhibited selectivity for subsets of stimuli with specific statistics, over the population responses were stable. These results contribute to our understanding of how auditory cortex processes natural sound statistics. In chapter 3, we review studies examining the role of different cortical inhibitory interneurons in shaping sound responses in auditory cortex. We identify the findings that support each other and the mechanisms that remain unexplored. In chapter 4, we tested how direct feedback from auditory cortex to the inferior colliculus modulated sound responses in the inferior colliculus. We optogenetically activated or suppressed cortico-collicular feedback while recording neuronal spiking in the mouse inferior colliculus in response to pure tones and dynamic random chords. We found that feedback modulated sound responses by reducing sound selectivity by decreasing responsiveness to preferred frequencies and increasing responsiveness to less preferred frequencies. Furthermore, we tested the effects of perturbing intra-cortical inhibitory-excitatory networks on sound responses in the inferior colliculus. We optogenetically activated or suppressed parvalbumin-positive (PV) and somatostatin-positive (SOM) interneurons while recording neuronal spiking in mouse auditory cortex and inferior colliculus. We found that modulation of neither PV- nor SOM-interneurons affected sound-evoked responses in the inferior colliculus, despite significant modulation of cortical responses. Our findings imply that cortico-collicular feedback can modulate responses to simple and complex auditory stimuli independently of cortical inhibitory interneurons. These experiments elucidate the role of descending auditory feedback in shaping sound responses. Together these results implicate the importance of the auditory cortex in sound processing.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 918 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exploring the Structural and Functional Organization of the Dorsal Zone of Auditory Cortex in Hearing and Deafness written by Melanie A. Kok and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent neuroscientific research has focused on cortical plasticity, which refers to the ability of the cerebral cortex to adapt as a consequence of experience. Over the past decade, an increasing number of studies have convincingly shown that the brain can adapt to the loss or impairment of a sensory system, resulting in the expansion or heightened ability of the remaining senses. A particular region in cat auditory cortex, the dorsal zone (DZ), has been shown to mediate enhanced visual motion detection in deaf animals. The purpose of this thesis is to further our understanding of the structure and function of DZ in both hearing and deaf animals, in order to better understand how the brain compensates following insult or injury to a sensory system, with the ultimate goal of improving the utility of sensory prostheses. First, I demonstrate that the brain connectivity profile of animals with early- and late-onset deafness is similar to that of hearing animals, but the projection strength to visual brain regions involved in motion processing increases as a consequence of deafness. Second, I specifically evaluate the functional impact of the strongest auditory connections to area DZ using reversible deactivation and electrophysiological recordings. I show that projections that ultimately originate in primary auditory cortex (A1) form much of the basis of the response of DZ neurons to auditory stimulation. Third, I show that almost half of the neurons in DZ are influenced by visual or somatosensory information. I further demonstrate that this modulation by other sensory systems can have effects that are opposite in direction during different portions of the auditory response. I also show that techniques that incorporate the responses of multiple neurons, such as multi-unit and local field potential recordings, may vastly overestimate the degree to which multisensory processing occurs in a given brain region. Finally, I confirm that individual neurons in DZ become responsive mainly to visual stimulation following deafness. Together, these results shed light on the function and structural organization of area DZ in both hearing and deaf animals, and will contribute to the development of a comprehensive model of cross-modal plasticity.

Download or read book Contributions of Auditory Cortex to Rat Auditory Event Related Brain Potentials written by Gregory Verne Simpson and published by . This book was released on 1987 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plasticity and Perception in Primary Auditory Cortex written by Hania Kover and published by . This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: During an early epoch of development, the brain is highly adaptive to the stimulus environment. Repeatedly exposing young animals to a particular tone, for example, leads to an enlarged representation of that tone in primary auditory cortex. While the neural effects of simple, single-frequency tonal environments are well characterized, the principles that guide plasticity in complex tone environments, as well as the perceptual consequences of cortical plasticity, remain unclear. To address these questions, this dissertation documents the neural and perceptual effects of simple and complex manipulations to the early acoustic environment. First, I show that rearing rat pups in a multi-tone environment leads to complex primary cortical representational changes that are related to the statistical relationships between experienced sounds. Specifically, tones that occur together within short temporal sequences tend to be represented by the same groups of neurons, whereas tones that occur separately are represented separately. This suggests that the development of primary auditory cortical response properties is sensitive to higher-order statistical relationships between sounds. The observed neural changes are accompanied by perceptual changes. Discrimination ability for sounds that never occur together within temporal sequences is improved. Heightened perceptual sensitivity is correlated with heightened neuronal response contrasts. These results suggest that early experience-dependent neural changes can mediate perceptual changes that may be related to statistical learning. Finally, I develop and experimentally test a model of the relationship between cortical sensory representations and perception. The model suggests that cortical stimulus representations may function as the neural representation of previously encountered stimulus probabilities, and makes predictions about how changes in these representations should affect perception within a statistical inference framework. Preliminary behavioral results support the model predictions, suggesting that one function of early experience-dependent plasticity may be to internalize stimulus distributions to shape future perception and behavior.

Download or read book Dissociated Lateralization of Transient and Sustained Blood Oxygen Level dependent Signal Components in Human Primary Auditory Cortex written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Among other auditory operations, the analysis of different sound levels received at both ears is fundamental for the localization of a sound source. These so-called interaural level differences, in animals, are coded by excitatory- nhibitory neurons yielding asymmetric hemispheric activity patterns with acoustic stimuli having maximal interaural level differences. In human auditory cortex, the temporal blood oxygen level-dependent (BOLD) response to auditory inputs, as measured by functional magnetic resonance imaging (fMRI), consists of at least two independent components: an initial transient and a subsequent sustained signal, which, on a different time scale, are consistent with electrophysiological human and animal response patterns. However, their specific functional role remains unclear. Animal studies suggest these temporal components being based on different neural networks and having specific roles in representing the external acoustic environment. Here we hypothesized that the transient and sustained response constituents are differentially involved in coding interaural level differences and therefore play different roles in spatial information processing. Healthy subjects underwent monaural and binaural acoustic stimulation and BOLD responses were measured using high signal-to-noise-ratio fMRI. In the anatomically segmented Heschl gyrus the transient response was bilaterally balanced, independent of the side of stimulation, while in opposite the sustained response was contralateralized. This dissociation suggests a differential role at these two independent temporal response components, with an initial bilateral transient signal subserving rapid sound detection and a subsequent lateralized sustained signal subserving detailed sound characterization.