Download or read book Effects of Continuous Background Noise on the Representations of Tonal and Speech Stimuli in Cat Primary Auditory Cortex written by Sarah Wenlong Chuang Wong and published by . This book was released on 1998 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Association and Auditory Cortices written by Alan Peters and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume deals with some of the association areas of the cerebral cortex and with the auditory cortex. In the first chapter, by Deepak Pandya and Edward Yeterian, the general architectural features and connections of cortical associ ation areas are considered; as these authors point out, in primates the association areas take up a considerable portion of the total cortical surface. Indeed, it is the development of the association areas that accounts for the greatest differ ences between the brains of primate and non primate species, and these areas have long been viewed as crucial in the formation of higher cognitive and be havioral functions. In the following chapter, Irving Diamond, David Fitzpatrick, and James Sprague consider the question of whether the functions of the as sociation areas depend on projections from the sensory areas of the cortex. They use the visual cortex to examine this question and show that there is a great deal of difference between species in the amount of dependence, the differences being paralleled by variations in the manner in which the geniculate and pulvinar nuclei of the thalamus project to the striate and extra striate cortical areas. One of the more interesting and perhaps least understood of the association areas is the cingulate cortex, discussed by Brent Vogt. Cingulate cortex has been linked with emotion and with affective responses to pain, and in his chapter Vogt gives an account of its cytoarchitecture, connections, and functions.

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1998 with total page 784 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 Frontiers in Computational Neuroscience Editors Pick 2021 written by Si Wu and published by Frontiers Media SA. This book was released on 2022-01-21 with total page 268 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 Cumulated Index Medicus written by and published by . This book was released on 1974 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evidence for a Relationship Between the Suppression of Distortion Product Otoacoustic Emissions and Hearing Threshold written by Martin Pienkowski and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensory neural pathways develop through a combination of "pre-wiring" by innate processes and "re-wiring" by the external environment ("nature and nurture"). However, there is increasing evidence that the development of the systematic (topographic) representation of receptor space in the visual pathway (retinotopic map) does not require external light, but rather gradients of chemical markers and waves of spontaneous activity. Is the same true of the development of topographic sound frequency (tonotopic) maps in the auditory pathway? Single-unit responses to tone pip stimuli were isolated from numerous microelectrode penetrations of auditory cortex (under ketamine anesthesia) in the developing chinchilla ('laniger'), a precocious mammal. Results are reported at postnatal day 3 (P3), P15, P30 and from adult animals. Hearing sensitivity and spike firing rates were mature in the youngest group. Tonotopic maps in primary and secondary auditory cortex were also well-ordered and sharply tuned by P3. The representation of sound frequency in the chinchilla auditory pathway thus appears to reach maturity 'in utero', where external (and maternal) sounds are considerably attenuated, and might not contribute to the mechanism(s) involved. On the other hand, the spectral-temporal complexity of cortical receptive fields increased progressively (past P30) to adulthood. Increasing fractions of neurons responded to multiple frequency bands, distinct in space and/or time. This likely reflects the continuing postnatal emergence of lateral connections between cortical columns, perhaps to confer selectivity for recurring fragments of species-specific vocalizations, such as frequency stacks and glides. There are several key parallels in the timelines of chinchilla and human auditory system development. It may be, therefore, that inadequate sound stimulation in early infancy (e.g. due to chronic middle ear disease) does not affect the sensorineural machinery required for precise frequency resolution, but may prevent the emergence of more complex sound feature selectivity, and so contribute to impaired speech perception., Otoacoustic emissions are sounds produced by the cochlea of the inner ear. For example, if two tonal stimuli at frequencies f1 and f 2 are presented to the ear, a third spectral component can be measured in the ear canal at frequency 2f1-f2, named the cubic distortion product otoacoustic emission (DPOAE). For low levels of f 1 and f2, the dominant cause of distortion is believed to be the nonlinear operation of the cochlear amplifier, the biochemically-powered internal motor behind the ear's remarkable frequency selectivity and sensitivity. Since most cases of hearing loss result from an impairment of this amplification process, DPOAEs provide a fast, objective test of hearing status. However, because their levels correlate only weakly with audiometric thresholds, use of DPOAEs in the clinic is limited to a pass or fail screening for hearing defects. In a recent paper, David Mills (J Acoust Soc Am 103:507-523) proposed a novel algorithm for estimating the gain of the cochlear amplifier, not from DPOAE level, but from the manner in which the level decreased when a third stimulus tone, the suppressor, was applied simultaneously with f1 and f2. In this thesis, the validity of Mills' algorithm is investigated using two approaches. First, a relationship between suppression and gain is derived on the basis of a small number of assumptions motivated by established empirical findings. Second, it is shown, to a very high degree of certainty, that there exists a relationship between DPOAE suppressibility and hearing threshold (an indirect measure of active gain) in humans. It is concluded that DPOAE suppression is a direct, noninvasive window on the gain of the cochlear amplifier. It has tangible diagnostic potential and warrants further study.

Download or read book Effects of Temporal Cortex Ablations Upon Complex Auditory Discrimination in the Monkey written by James Carlyle Lynch and published by . This book was released on 1970 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Frequency Following Response written by Nina Kraus and published by Springer. This book was released on 2017-01-09 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume will cover a variety of topics, including child language development; hearing loss; listening in noise; statistical learning; poverty; auditory processing disorder; cochlear neuropathy; attention; and aging. It will appeal broadly to auditory scientists—and in fact, any scientist interested in the biology of human communication and learning. The range of the book highlights the interdisciplinary series of questions that are pursued using the auditory frequency-following response and will accordingly attract a wide and diverse readership, while remaining a lasting resource for the field.

Download or read book Society for Neuroscience Abstracts written by Society for Neuroscience. Meeting and published by . This book was released on 1992 with total page 998 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Single neuron Responses to Complex and Moving Sounds in the Primary Auditory Cortex of the Cat written by Anssi R. A. Sovijärvi and published by . This book was released on 1973 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Anthropogenic Noise on Animals written by Hans Slabbekoorn and published by Springer. This book was released on 2018-08-20 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past several years, many investigators interested in the effects of man-made sounds on animals have come to realize that there is much to gain from studying the broader literature on hearing sound and the effects of sound as well as data from the effects on humans. It has also become clear that knowledge of the effects of sound on one group of animals (e.g., birds or frogs) can guide studies on other groups (e.g., marine mammals or fishes) and that a review of all such studies together would be very useful to get a better understanding of the general principles and underlying cochlear and cognitive mechanisms that explain damage, disturbance, and deterrence across taxa. The purpose of this volume, then, is to provide a comprehensive review of the effects of man-made sounds on animals, with the goal of fulfilling two major needs. First, it was thought to be important to bring together data on sound and bioacoustics that have implications across all taxa (including humans) so that such information is generally available to the community of scholars interested in the effects of sound. This is done in Chaps. 2-5. Second, in Chaps. 6-10, the volume brings together what is known about the effects of sound on diverse vertebrate taxa so that investigators with interests in specific groups can learn from the data and experimental approaches from other species. Put another way, having an overview of the similarities and discrepancies among various animal groups and insight into the “how and why” will benefit the overall conceptual understanding, applications in society, and all future research.

Download or read book Tonal Localization on the Auditory Cortex of the Cat written by John Mason Schroeder and published by . This book was released on 1950 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Speech Sound Coding and Training induced Plasticity in Primary Auditory Cortex written by Crystal Tasha Engineer and published by . This book was released on 2008 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is important to understand how the human brain processes speech sounds in order to lead to perception. fMRI and EEG studies have shown that certain cortical regions are activated after hearing speech, but these techniques lack the temporal and spatial precision necessary to document the unique pattern of activation evoked by each speech sound. Previous studies have shown that the primary auditory cortex (A1) pattern of activity evoked in response to speech sounds is altered by the temporal features of the sound. In this study, we show that rats' (Rattus norvegicus) behavioral performance on consonant discrimination tasks is similar in key respects to human performance, and can be predicted from the spatiotemporal pattern of rat A1 activity when temporal information is maintained. When temporal information is ignored and the mean firing rate is used, behavioral performance cannot be predicted as accurately. We also document the ability of rats to categorize speech sounds by voicing or gender on the first day of training. This categorization ability is also predicted by the spatiotemporal pattern of A1 activity. Finally, we show that training on multiple speech discrimination tasks increases the proportion of neurons responding to low frequency tones, the threshold of A1 neurons, the response strength to tones, the receptive field size, and response latencies. Passive exposure to speech sounds increases the proportion of neurons responding to high frequency tones, and decreases the threshold of A1 neurons and response latencies. These results indicate that training on multiple speech tasks does not result in stimulus specific response enhancement in primary auditory cortex, but instead, results in generalized enhancement of untrained sounds following speech training. This result suggests that non-primary or higher cortical areas, as opposed to A1, may exhibit stimulus specificity after speech sound training.

Download or read book Development and Plasticity in the Primary Auditory Cortex written by Heesoo Kim and published by . This book was released on 2011 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The early acoustic environment plays a crucial role in how the brain represents sounds and how language phonemes are perceived. Human infants are born with the capacity to distinguish phonemes from virtually all languages, but very quickly change their perceptual ability to match that of their primary language. This has been described as the Perceptual Magnet Effect in humans, where phoneme tokens are perceived to be more similar than they physically are, leading to decreased discrimination ability. Early development is marked by distinct critical periods, when cortical regions are highly plastic and particularly sensitive to sensory input. These lasting alterations in cortical sensory representation may directly impact the perception of the external world. My thesis is comprised of three different studies, all of which investigate the role of the developmental acoustic environment on cortical representation and the behavioral consequence of altered cortical representation. Passive exposure to pure-tone pips during the auditory critical period can lead to over-representation of the exposure tone frequency in the primary auditory cortex (A1) of rats. This over-representation is associated with decreased discrimination ability of that frequency, similar to the Perceptual Magnet Effect in humans. Another hallmark of human language is categorical perception. Using a computational model of A1, I show that certain representation patterns (which may be achieved with passive exposure to two distinct pure-tone pips) in A1 can lead to categorical perception in rats. This suggests that cortical representation may be a mechanism that drives categorical perception. Rodents are socially vocal animals whose con-specific calls are often presented in bouts in the ultrasonic frequency range. These calls are vocalized at ethologically relevant repetition rates. I show that pure-tone pips that are presented at the ethological repetition rate (but not slower or faster rates) during the auditory critical period lead to over-representation of the pure-tone frequency. A certain subclass of ultrasonic vocalizations, the pup isolation calls, occurs during the auditory critical period. I show that there is over representation of ultrasonic vocalization frequencies in the rat A1. This preferential representation is experience-dependent and is associated with higher discrimination ability.

Download or read book Abstracts Society for Neuroscience written by Society for Neuroscience and published by . This book was released on 1994 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt: