Author: Ayoub Daliri Publisher: ISBN: Category : Auditory pathways Languages : en Pages : 96
Book Description
Stuttering is associated with atypical structural and functional connectivity among sensorimotor brain areas. However, it remains entirely unknown which specific mechanisms of sensorimotor control are affected by these neurological differences. In the program of research described here, I used a novel experimental paradigm and electroencephalographic (EEG) recordings to study motor-to-sensory interactions during speech movement planning in stuttering versus nonstuttering speakers. Experiment 1 investigated whether stuttering adults are deficient in modulating the auditory system prior to speech initiation. Auditory modulation was examined by recording auditory evoked potentials in response to probe tones presented during movement planning in a delayed-response speaking condition as compared with no-speaking control conditions. Findings indicated that stuttering speakers did not show the modulation of auditory processing (reflected in reduced amplitude of the N1 component) that was observed in nonstuttering speakers. This finding raised the question whether stuttering individuals have problems specifically with generating or evaluating a planning-related efference copy signal that can be used to predict upcoming self-generated sensory inputs or, more generally, with using any available information to make sensory predictions. In Experiment 2, probe tones were therefore delivered while participants anticipated either self-producing speech or hearing their own pre-recorded speech played back and in a control condition without auditory input. Results showed that auditory modulation differed between stuttering and normally fluent adults in both conditions with predictable auditory input. Experiment 3 was designed to start exploring the functional significance of pre-speech auditory modulation in general, and the functional implications of stuttering speakers' lack of modulation. Participants in this experiment completed a sensorimotor adaptation task with formant-shifted auditory feedback, and the results served to estimate each speaker's reliance on auditory feedback. In a separate session, pre-speech auditory modulation was again assessed by means of probe tones, but this time N1 modulation relative to a no-speaking control condition was quantified both in a condition that allowed typical reliance on auditory feedback (non-delayed auditory feedback; NAF) and in a condition that did not allow reliance on auditory feedback (delayed auditory feedback; DAF). Results revealed that (a) stuttering speakers showed only limited adaptation to formant-shifted auditory feedback; (b) for nonstuttering speakers, DAF caused the amount of pre-speech auditory modulation to be reduced whereas for stuttering speakers, DAF enhanced pre-speech auditory modulation; and (c) across the two groups, there was a relationship between the effect of DAF on pre-speech auditory modulation and reliance on auditory feedback during the adaptation task. These studies demonstrate that stuttering individuals have difficulties with using auditory predictions--both those related to active movement planning and those related to input that is not a consequence of one's own actions--to prime this sensory system with critical importance for speech production. Moreover, stuttering individuals showed not only a lack of modulation of the auditory system under normal speaking conditions (NAF) but also a lower reliance on auditory feedback as revealed here during a sensorimotor adaptation task with formant-shifted auditory feedback. Overall, findings suggest that stuttering is associated with deficits in auditory-motor integration, and that the auditory system may be not appropriately modulated for its role in online feedback control during speech production. I speculate that the inability to use predictive information for appropriately priming task-relevant sensory systems for their role in monitoring articulatory movements may lead to unnecessary and disruptive attempts at correcting ongoing movements. These maladaptive "repairs" may contribute to the fluency breakdowns that form the primary symptoms of stuttering.
Author: Hee-Cheong Chon Publisher: ISBN: Category : Languages : en Pages :
Book Description
The overall purpose of this dissertation was to identify the effects of delayed auditory feedback (DAF) on speech motor stability and speech fluency in normally fluent adults (PWNS) and to compare them with effects on adults who exhibit persistent stuttering. If the auditory processing influences differently the two groups, it might shed light on the basic role of auditory-to-motor integration in speech production. Differences in auditory feedback dependency were also expected between normally fluent individuals who are highly susceptible to DAF and normally fluent individuals who are minimally affected by DAF. Three studies were conducted to (I) subgroup 62 normally fluent males and females based on their responses to DAF during spontaneous conversational speaking and reading tasks, (II) compare responses to DAF between 15 normally fluent adults who showed high stuttering-like disfluencies (SLD) under DAF (High-SLD group), 15 normally fluent adults who showed low SLD under DAF (Low-SLD group), and 15 adults who stutter, and (III) compare the specific effects of DAF on speech motor stability and movement patterns (lower-lip movement) in 11 normally fluent adults versus 11 adults who stutter. Study I revealed that normally fluent participants, as a group, increased the amount of SLD and speech errors (SE), and decreased articulation rate (AR) when speaking under DAF relative to speaking under amplified non-delayed condition (aNAF). Sex had a limited differential effect on other disfluencies (OD) and AR whereas task effects were seen in OD, SE, and AR. Neither sex nor task, however, did influence SLD. Three subgroups, Low, Middle, and High Responders were identified. There were clear differences between the Low and High Responders in that the Low Responders exhibited smaller numbers of SLD and SE as well as faster AR than the High Responders. The Middle Responders revealed task dependency, showing different responses than those exhibited by the Low and High Responders. The results of Study II showed that people who stutter did not reduce SLD counts under DAF condition, a finding that deviates from reports of previous studies. PWS also exhibited higher mean number of SLD than the normally fluent Low-SLD group but similar to that of normally fluent High-SLD group. For all groups, the number of SE was higher and AR was slower under DAF than aNAF. PWS showed larger individual variability in responses to aNAF compared to natural feedback conditions in that some PWS reduced SLD under aNAF condition. Study III revealed significant difference between PWS and PWNS in speech kinematic stabilities, showing that PWS exhibited higher spatio-temporal index (i.e., lower speech motor stability) than PWNS across auditory feedback conditions in four utterance stimuli. PWS, however, yielded higher speech movement stability under aNAF and 25ms-DAF in longer stimuli compared to natural feedback condition. There was no group difference in movement displacement and velocity for opening-closing sequential movements but the patterns were different in each group. PWNS showed lower displacement and velocity under aNAF and DAF compared to natural feedback condition for both opening and closing movements whereas PWS showed higher displacement under DAF than aNAF condition and higher velocity under nNAF than 25ms-DAF. Normally fluent people showed shorter movement duration and faster articulation rate than PWS across auditory feedback and stimuli. This dissertation study has demonstrated different influences of auditory feedback on speech motor control in normally fluent adults and adults who stutter. In both groups, individual variability was obvious. In normally fluent adults, diverse responses to DAF could be explained with different auditory feedback dependency for ongoing speech articulatory production. PWS were more dependent on auditory feedback for speech production, and auditory-to-motor integration under aNAF and short delay feedback conditions helped them to improve speech motor stability.
Author: Oliver Bloodstein Publisher: Plural Publishing ISBN: 1635503183 Category : Medical Languages : en Pages : 600
Book Description
The revised edition of A Handbook on Stuttering continues its remarkable role as the authoritative, first-line resource for researchers and clinicians who work in the field of fluency and stuttering. Now in its seventh edition, this unique book goes beyond merely updating the text to include coverage of roughly 1,000 articles related to stuttering research and practice that have been published since 2008. This extended coverage integrates the more traditional body of research with evolving views of stuttering as a multi-factorial, dynamic disorder. Comprehensive, clear, and accurate, this text provides evidence-based, practical information critical to understanding stuttering. By thoroughly examining the intricacies of the disorder, A Handbook on Stuttering, Seventh Edition lays the foundation needed before considering assessment and treatment. New to the Seventh Edition: * A completely reorganized table of contents, including two new chapters. * The deletion of approximately 1,000 non-peer-reviewed references from the previous edition to assure discussion of the highest quality evidence on stuttering. * New content on the development of stuttering across the lifespan and assessment. * Given the Handbook’s historic role as a primary reference for allied professionals, a new chapter that addresses myths and misconceptions about stuttering * Expanded coverage on the role of temperament in childhood stuttering * Expanded coverage of brain-based research, genetics, and treatment findings. * A thoroughly updated chapter on conditions under which stuttering fluctuates * Brief tutorial overviews of critical concepts in genetics, neuroimaging, language analysis and other relevant constructs, to better enable reader appreciation of research findings. * A greater selection of conceptual illustrations of basic concepts and findings than in prior editions * Integrated cross-referencing to content across chapters
Author: Hermann F.M. Peters Publisher: Springer Science & Business Media ISBN: 3709169690 Category : Medical Languages : en Pages : 410
Book Description
The present book arose from a conference on Speech Motor Dynamics in Stuttering held at the University of Nijmegen in Nijmegen, the Netherlands from June 13-15, 1985. The conference was organized on the occasion of the 25th anniversary of the Department of Speech Pathology of the University Hospital. The topic selected for the conference and now developed within this book, Speech Motor Dynamics in Stuttering, was judged to be particularly timely and especially relevant to an emerging body of work on stuttering. For over ten years there had been no confer ences that brought together researchers who have worked on stuttering from perspectives stressing the dynamics of motor processes. Yet during that time major changes have occurred in research on stuttering which signify a growing level of scientific maturity within the problem area. This book attempts to character ize a number of major trends in research on speech motor processes in stuttering. There has been a lessening in the postulation of causes of stuttering in the form of global hypothesis which have tenuous ties to empi rical data. New ideas about speech motor processes in stuttering have been stimulated by researchers who have done productive work on more general issues of motor control. This book therefore directs our attention to a number of models of speech production which are relevant to stuttering.
Author: Ann Packman Publisher: Taylor & Francis ISBN: 1317265386 Category : Psychology Languages : en Pages : 197
Book Description
Despite decades of research into the nature and treatment of stuttering, the causes and underlying mechanisms of it are still not well understood. In this unique and comprehensive overview of the numerous theories and models which seek to understand and explain stuttering, the authors of Theoretical Issues in Stuttering provide an invaluable account. Covering an impressive range of topics including past and current theories of stuttering, this edition provides the reader with an updated evaluation of the literature on the subject of stuttering alongside exploring the evolution of new theories. Placing each within the relevant historical context, the authors explore the contribution of theory to both understanding and managing stuttering. Theoretical Issues in Stuttering is a critical account of the models and theories which surround the subject of stuttering, aiming to act as a key resource for students of speech-language pathology as well as lecturers, clinicians and researchers within the field.
Author: Ben Maassen Publisher: Oxford University Press ISBN: 019852627X Category : Language Arts & Disciplines Languages : en Pages : 482
Book Description
Speaking is one of the most complex skills that humans perform. This volume presents state of the art research in the science of speech motor control and speech disorders. This will be an important volume for all those involved in speech research and speech pathology, including those from the disciplines of psychology, neurology, and ENT.
Author: Feiran Yang Publisher: ISBN: Category : Languages : en Pages : 36
Book Description
During the Event-related potential (ERP) study, ideally, the EEG recording only contains the event-related signal. However, there could exist irrelevant signals and noise. Unconscious activities, such as eye movement and muscle movement, and activities caused by the design of the experiment, could occur during the recording sessions. Meanwhile, due to the hyperactive nature of the child, there is more irrelevant signal inside child EEG signals. To solve this problem. there are three methods discussed in this paper, which are averaging, independent component analysis (ICA), and Autoencoder. Averaging is the classical method applying to process data in ERP studies. Two advantages of this method are: 1) preserving the original information of the data most 2) eliminating non-activity-related Gaussian noise. There also are two pitfalls: 1) reducing the number of epoch in each group 2) failing to remove the irrelevant activity-related signals. This method is also unable to get useful information from the child data. And the signal to noise ratio (SNR) of this method is 30.21 for adult subjects. ICA, a linear blind source separation method, is also a common method used by some of the studies. There are two advantages to this method: 1) preserving the number of epoch in each group. 2) removing the irrelevant eye movement and muscle movement signals. One pitfall is that bad rejection choice may cause losing information. This method improves some of the results in child subjects. And the SNR of this method is 33.02 for adult subjects, which is higher than averaging. Autoencoder is a nonlinear dimensionality reduction method. By creating proper loss function, a nonlinear independent feature learning method is applied to the EEG signals. The advantages are 1) nonlinearly learning the feature and linearly reconstructing the data at the same time 2) dimensionality reduction. One pitfall is currently no localization method to validate the features. And the SNR of this method is 22.94 for adult subjects, which is lower than averaging. And Autoencoder also can process part of the child data.
Author: Ayoub Daliri
Author: Hee-Cheong Chon
Author: Oliver Bloodstein
Author: Hermann F.M. Peters
Author: Ann Packman
Author: Pierpaolo Busan
Author: Ben Maassen
Author: Feiran Yang
Author: Edward A. Lee
Author: James V. Frick