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ABSTRACT: Recent brain imaging investigations of developmental stuttering show considerable disagreement regarding which regions are related to stuttering. These divergent findings have been mainly derived from group studies. To investigate functional neurophysiology with improved precision, an individual-participant approach (N=4) using event-related functional magnetic resonance imaging and test-retest reliability measures was performed while participants produced fluent and stuttered single words during two separate occasions. A parallel investigation required participants to imagine stuttering or not stuttering on single words. The overt and covert production tasks produced considerable within-subject agreement of activated voxels across occasions, but little within-subject agreement between overt and covert task activations. However, across-subject agreement for regions activated by the overt and covert tasks was minimal. These results suggest that reliable effects of stuttering are participant-specific, an implication that might correspond to individual differences in stuttering severity and functional compensation due to related structural abnormalities.
Brain and Language 01/2013; 124(2):153-164. · 3.12 Impact Factor
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ABSTRACT: PURPOSE: This study examined the effect of speech rate on phonated intervals (PIs), in order to test whether a reduction in the frequency of short PIs is an important part of the fluency-inducing mechanism of chorus reading. The influence of speech rate on stuttering frequency, speaker-judged speech effort, and listener-judged naturalness was also examined. An added purpose was to determine if chorus reading could be further refined so as to provide a perceptual guide for gauging the level of physical effort exerted during speech production. METHODS: A repeated-measures design was used to compare data obtained during control reading conditions and during several chorus reading conditions produced at different speech rates. Participants included 8 persons who stutter (PWS) between the ages of 16 and 32years. RESULTS: There were significant reductions in the frequency of short PIs from the habitual reading condition during slower chorus conditions, no change when speech rates were matched between habitual reading and chorus conditions, and an increase in the frequency of short PIs during chorus reading produced at a faster rate than the habitual condition. Speech rate did not have an effect on stuttering frequency during chorus reading. In general, speech effort ratings improved and naturalness ratings worsened as speech rate decreased. CONCLUSION: These results provide evidence that (a) a reduction in the frequency of short PIs is not necessary for fluency improvement during chorus reading, and (b) speech rate may be altered to provide PWS with a more appropriate reference for how physically effortful normally fluent speech production should be. Future investigations should examine the necessity of changes in the activation of neural regions during chorus reading, the possibility of defining individualized units on a 9-point effort scale, and if there are upper and lower speech rate boundaries for receiving ratings of "highly natural sounding" speech during chorus reading. Learning outcomes: The reader will be able to: (1) describe the effect of changes in speech rate on the frequency of short phonated intervals during chorus reading, (2) describe changes to speaker-judged speech effort as speech rate changes during chorus reading, (3) and describe the effect of changes in speech rate on listener-judged naturalness ratings during chorus reading.
Journal of Communication Disorders 12/2012; · 1.76 Impact Factor
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ABSTRACT: Many differences in brain activity have been reported between persons who stutter (PWS) and typically fluent controls during oral reading tasks. An earlier meta-analysis of imaging studies identified stutter-related regions, but recent studies report less agreement with those regions. A PET study on adult dextral PWS (n=18) and matched fluent controls (CONT, n=12) is reported that used both oral reading and monologue tasks. After correcting for speech rate differences between the groups the task-activation differences were surprisingly small. For both analyses only some regions previously considered stutter-related were more activated in the PWS group than in the CONT group, and these were also activated during eyes-closed rest (ECR). In the PWS group, stuttering frequency was correlated with cortico-striatal-thalamic circuit activity in both speaking tasks. The neuroimaging findings for the PWS group, relative to the CONT group, appear consistent with neuroanatomic abnormalities being increasingly reported among PWS.
Brain and Language 05/2012; 122(1):11-24. · 3.12 Impact Factor
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ABSTRACT: It is proposed that stuttering treatment, particularly for adults and adolescents who stutter, may benefit from more inventive and extensive use of functional measurement-measures that are also treatment agents. Such measures can be tailored to produce more personally significant and evidence-based treatment benefits. They may be especially useful when employed in conjunction with partial self-management and performance-contingent procedures.
Previous approaches to the definition of stuttering treatment goals and the measurement of stuttering treatment outcomes are critically reviewed. Suggestions for improvements are presented within the framework of an evidence-based and relatively standardized stuttering treatment.
Results from a review of existing literature and from 2 case studies show that 2 specific personally significant problems, saying one's name and addressing large audiences, were improved by implementing these strategies in treatment. Functional measures directly connected to treatment, and partially self-managed performance-contingent schedules, merit further research as methodologies that are suitable for conducting personally significant and evidence-based treatments with adults and adolescents who stutter.
American Journal of Speech-Language Pathology 04/2012; 21(3):264-77. · 2.03 Impact Factor
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ABSTRACT: To relate changes in four variables previously defined as characteristic of normally fluent speech to changes in phonatory behavior during oral reading by persons who stutter (PWS) and normally fluent controls under multiple fluency-inducing (FI) conditions.
Twelve PWS and 12 controls each completed 4 ABA experiments. During A phases, participants read normally. B phases were 4 different FI conditions: auditory masking, chorus reading, whispering, and rhythmic stimulation. Dependent variables were the durations of accelerometer-recorded phonated intervals; self-judged speech effort; and observer-judged stuttering frequency, speech rate, and speech naturalness. The method enabled a systematic replication of Ingham et al. (2009).
All FI conditions resulted in decreased stuttering and decreases in the number of short phonated intervals, as compared with baseline conditions, but the only FI condition that satisfied all four characteristics of normally fluent speech was chorus reading. Increases in longer phonated intervals were associated with decreased stuttering but also with poorer naturalness and/or increased speech effort. Previous findings concerning the effects of FI conditions on speech naturalness and effort were replicated.
Measuring all relevant characteristics of normally fluent speech, in the context of treatments that aim to reduce the occurrence of short-duration PIs, may aid the search for an explanation of the nature of stuttering and may also maximize treatment outcomes for adults who stutter.
The reader will be able to (1) understand the differential effects of four well established fluency-inducing conditions on the quality of fluency of adult PWS and controls, (2) learn how intervals of phonation are modified during these conditions and (3) how the duration of specific intervals of phonation may be identified for their potential application in stuttering treatment.
Journal of Communication Disorders 02/2012; 45(3):198-211. · 1.76 Impact Factor
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ABSTRACT: High-density ERPs were recorded in eight adults with persistent developmental stuttering (PERS) and eight matched normally fluent (CONT) control volunteers while participants either repeatedly uttered the vowel 'ah' or listened to their own previously recorded vocalizations. The fronto-central N1 auditory wave was reduced in response to spoken vowels relative to heard vowels (auditory-vocal gating), but no difference in the extent of such modulation was found in the PERS group. Abnormalities in the PERS group were restricted to the LISTEN condition, in the form of early N1 and late N3 amplitude changes. Voltage of the N1 wave was significantly reduced over right inferior temporo-occipital scalp in the PERS group. A laterality index derived from N1 voltage moderately correlated with the PERS group's assessed pre-experiment stuttering frequency. Source localization with sLORETA (Pascual-Marqui, R. D. (2002). Standardized low-resolution brain electromagnetic tomography (sLORETA): Technical details. Methods & Findings in Experimental & Clinical Pharmacology, 24, 5-12.) revealed that at the peak of the N1 the PERS group displayed significantly greater current density in right primary motor cortex than the CONT group, suggesting abnormal early speech-motor activation. Finally, the late N3 wave was reduced in amplitude over inferior temporo-occipital scalp, more so over the right hemisphere. sLORETA revealed that in the time window of the N3 the PERS group showed significantly less current density in right secondary auditory cortex than the CONT group, suggesting abnormal speech sound perception. These results point to a deficit in auditory processing of speech sounds in persistent developmental stuttering, stemming from early increased activation of right rolandic area and late reduced activation in right auditory cortex.
Brain and Language 11/2010; 115(2):141-7. · 3.12 Impact Factor
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Roger J Ingham
Journal of clinical psychopharmacology 10/2010; 30(5):649-50; author reply 650-1. · 5.09 Impact Factor
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ABSTRACT: To investigate the effects of 4 fluency-inducing (FI) conditions on self-rated speech effort and other variables in adults who stutter and in normally fluent controls.
Twelve adults with persistent stuttering and 12 adults who had never stuttered each completed 4 ABA-format experiments. During A phases, participants read aloud normally. During each B phase, they read aloud in 1 of 4 FI conditions: auditory masking, chorus reading, whispering, and rhythmic speech. Dependent variables included self-judged speech effort and observer-judged stuttering frequency, speech rate, and speech naturalness.
For the persons who stuttered, FI conditions reduced stuttering and speech effort, but only for chorus reading were these improvements obtained without diminishing speech naturalness or speaking rate. By contrast, speech effort increased during all FI conditions for adults who did not stutter.
Self-rated speech effort differentiated the effects of 4 FI conditions on speech performance for adults who stuttered, with chorus reading best approximating normally fluent speech. More generally, self-ratings of speech effort appeared to constitute an independent, reliable, and validly interpretable dimension of fluency that may be useful in the measurement and treatment of stuttering.
Journal of Speech Language and Hearing Research 09/2009; 52(5):1286-301. · 1.88 Impact Factor
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ABSTRACT: To determine whether stuttering judgment accuracy is influenced by familiarity with the stuttering speaker's language.
Audiovisual 7-min speech samples from nine 3- to 5-year-olds were used. Icelandic children who stutter (CWS), preselected for different levels of stuttering, were subdivided into 5-s intervals. Ten experienced Icelandic speech-language pathologists (ICE-SLPs) and 10 experienced U.S. speech-language pathologists (US-SLPs), the latter being unfamiliar with the Icelandic language, independently judged each 5-s interval (n = 756) as stuttered or nonstuttered on 2 separate occasions.
As in previous studies, intervals judged to contain stuttering showed wide variability within the ICE-SLP and US-SLP groups. However, both SLP groups (a) displayed satisfactory mean intrajudge agreement, (b) met an independent stuttering judgment accuracy criterion test using English-speaking CWS samples, and (c) met an agreement criterion on approximately 90% of their stuttering and nonstuttering judgments on the Icelandic-speaking CWS samples.
Experienced SLPs were shown to be highly accurate in recognizing stuttering and nonstuttering exemplars from young CWS speaking in an unfamiliar language. The findings suggest that judgments of occurrences of stuttering in CWS are not generally language dependent, although some exceptions were noted.
Journal of Speech Language and Hearing Research 05/2009; 52(3):766-79. · 1.88 Impact Factor
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ABSTRACT: The aims of this study were to present a method for developing a path analytic network model using data acquired from positron emission tomography. Regions of interest within the human brain were identified through quantitative activation likelihood estimation meta-analysis. Using this information, a "true" or population path model was then developed using Bayesian structural equation modeling. To evaluate the impact of sample size on parameter estimation bias, proportion of parameter replication coverage, and statistical power, a 2 group (clinical/control) × 6 (sample size: N = 10, N = 15, N = 20, N = 25, N = 50, N = 100) Markov chain Monte Carlo study was conducted. Results indicate that using a sample size of less than N = 15 per group will produce parameter estimates exhibiting bias greater than 5% and statistical power below .80.
Structural Equation Modeling A Multidisciplinary Journal 01/2009; 16(1):147-162. · 4.71 Impact Factor
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ABSTRACT: To evaluate the efficacy of a standardized training program to improve preschool teachers' ability to identify occurrences of stuttering accurately and reliably in preschool children who stutter (CWS).
An Icelandic version of the Stuttering Measurement Assessment and Training (SMAAT) program [Ingham, R. J., Cordes, A. K., Kilgo, M., & Moglia, R. (1998). Stuttering measurement assessment and training (SMAAT). Santa Barbara, CA: University of California, Santa Barbara] was developed using 2-min audio-visual recordings of nine Icelandic-speaking CWS (3-5 years). Twenty preschool teachers from preschools in Iceland volunteered to participate and were randomly allocated to an experimental and control group. The preschool teachers judged stuttering on nine pre-judged, interval-classified speech samples on two occasions 2-3 weeks apart; only the experimental group received judgment training between Occasion 1 and 2.
The experimental and control groups displayed, on average, above 80% accuracy in identifying stuttering in the sampled CWS, even prior to training. After training the experimental group showed significantly higher mean percent judgment accuracy (p<.01), while the control group's mean accuracy level showed no significant difference between Occasion 1 and 2.
The interval-based training program did improve the accuracy with which the judges identified stuttering in preschool CWS. However, the findings also showed that the preschool teachers possessed relatively satisfactory stuttering judgment skills, even without training.
The reader will be able to (a) explain the development of a procedure for establishing standardized training material for measuring and identifying stuttering in preschool children, (b) evaluate whether preschool teachers are generally accurate judges of stuttering in young children, and (c) describe how their stuttering judgment accuracy can be improved through training.
Journal of fluency disorders 09/2008; 33(3):167-79. · 2.19 Impact Factor
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ABSTRACT: To illustrate the way in which both fluency shaping (FS) and stuttering management (SM) treatments for developmental stuttering in adults are evidence based.
A brief review of the history and development of FS and SM is provided. It illustrates that both can be justified as evidence-based treatments, each treatment seeking evidence of a different kind: FS seeks evidence concerning treatment outcome, and SM seeks evidence concerning the nature of the stutter event.
Although outcome evidence provides the principal support for FS, support for SM comes principally from a cognitive learning model of defensive behavior as applied to the nature of the stutter event. Neither approach can claim anything like uniform success with adults who stutter. However, self-management and modeling are strategies common to both approaches and have shown consistently positive effects on outcome. It is argued that both strategies merit additional treatment efficacy study. Cognitive behavior theory may provide a useful framework for this research.
Journal of Speech Language and Hearing Research 09/2008; 52(1):254-63. · 1.88 Impact Factor
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ABSTRACT: Previous investigations of cerebral anatomy in persistent developmental stutterers have reported bilateral anomalies in the perisylvian region and atypical patterns of cerebral asymmetry. In this study, perisylvian sulcal patterns were analyzed to compare subjects with persistent developmental stuttering (PDS) and an age-, hand-, and gender-matched control group. This analysis was accomplished using software designed for 3-dimensional sulcal identification and extraction. Patterns of cerebral asymmetry were also investigated with standard planimetric measurements. PDS subjects showed a small but significant increase in both the number of sulci connecting with the second segment of the right Sylvian fissure and in the number of suprasylvian gyral banks (of sulci) along this segment. No differences were seen in the left perisylvian region for either sulcal number or gyral bank number. Measurements of asymmetry revealed typical patterns of cerebral asymmetry in both groups with no significant differences in frontal and occipital width asymmetry, frontal and occipital pole asymmetry, or planum temporale and Sylvian fissure asymmetries. The subtle difference in cortical folding of the right perisylvian region observed in PDS subjects may correlate with functional imaging studies that have reported increased right-hemisphere activity during stuttered speech.
Cerebral Cortex 04/2008; 18(3):571-83. · 6.54 Impact Factor
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ABSTRACT: To complete a systematic review, with trial quality assessment, of published research about behavioral, cognitive, and related treatments for developmental stuttering. Goals included the identification of treatment recommendations and research needs based on the available high-quality evidence about stuttering treatment for preschoolers, school-age children, adolescents, and adults.
Multiple readers reviewed 162 articles published between 1970 and 2005, using a written data extraction instrument developed as a synthesis of existing standards and recommendations. Articles were then assessed using 5 methodological criteria and 4 outcomes criteria, also developed from previously published recommendations.
Analyses found 39 articles that met at least 4 of the 5 methodological criteria and were considered to have met a trial quality inclusion criterion for the purposes of this review. Analysis of those articles identified a range of stuttering treatments that met speech-related and/or social, emotional, or cognitive outcomes criteria.
Review of studies that met the trial quality inclusion criterion established for this review suggested that response-contingent principles are the predominant feature of the most powerful treatment procedures for young children who stutter. The most powerful treatments for adults, with respect to both speech outcomes and social, emotional, or cognitive outcomes, appear to combine variants of prolonged speech, self-management, response contingencies, and other infrastructural variables. Other specific clinical recommendations for each age group are provided, as are suggestions for future research.
American Journal of Speech-Language Pathology 12/2006; 15(4):321-41. · 2.03 Impact Factor
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ABSTRACT: To complete a systematic review, incorporating trial quality assessment, of published research about pharmacological treatments for stuttering. Goals included the identification of treatment recommendations and research needs based on the available high-quality evidence.
Multiple readers reviewed 31 articles published between 1970 and 2005, using a written data extraction instrument developed as a synthesis of existing standards and recommendations. Articles were then assessed using 5 methodological criteria and 4 outcomes criteria, also developed from previously published recommendations.
None of the 31 articles met more than 3 of the 5 methodological criteria (M = 1.74). Four articles provided data to support a claim of short-term improvement in social, emotional, or cognitive variables. One article provided data to show that stuttering frequency was reduced to less than 5%, and 4 additional articles provided data to show that stuttering may have been reduced by at least half. Among the articles that met the trial quality inclusion criterion for the second stage of this review, none provided uncomplicated positive reports.
None of the pharmacological agents tested for stuttering have been shown in methodologically sound reports to improve stuttering frequency to below 5%, to reduce stuttering by at least half, or to improve relevant social, emotional, or cognitive variables. These findings raise questions about the logic supporting the continued use of current pharmacological agents for stuttering.
American Journal of Speech-Language Pathology 12/2006; 15(4):342-52. · 2.03 Impact Factor
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ABSTRACT: The purpose of this study was to investigate chorus reading's (CR's) effect on speech effort during oral reading by adult stuttering speakers and control participants. The effect of a speech effort measurement highlighting strategy was also investigated.
Twelve persistent stuttering (PS) adults and 12 normally fluent control participants completed 1-min base rate readings (BR-nonchorus) and CRs within a BR/CR/BR/CR/BR experimental design. Participants self-rated speech effort using a 9-point scale after each reading trial. Stuttering frequency, speech rate, and speech naturalness measures were also obtained. Instructions highlighting speech effort ratings during BR and CR phases were introduced after the first CR.
CR improved speech effort ratings for the PS group, but the control group showed a reverse trend. Both groups' effort ratings were not significantly different during CR phases but were significantly poorer than the control group's effort ratings during BR phases. The highlighting strategy did not significantly change effort ratings.
The findings show that CR will produce not only stutter-free and natural sounding speech but also reliable reductions in speech effort. However, these reductions do not reach effort levels equivalent to those achieved by normally fluent speakers, thereby conditioning its use as a gold standard of achievable normal fluency by PS speakers.
Journal of Speech Language and Hearing Research 07/2006; 49(3):660-70. · 1.88 Impact Factor
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ABSTRACT: Previous research has demonstrated the fluency-improving effect of reducing the occurrence of short-duration, phonated intervals (PIs; approximately 30-150 ms) in individuals who stutter, prompting the hypothesis that PIs in these individuals' speech are not distributed normally, particularly in the short PI ranges. It has also been hypothesized that this nonnormal PI distribution will be present during the stutter-free speech of affected persons.
A comparison was made between the distributions of PIs during oral reading by adolescent and adult speakers who stuttered (n=13; 11 males) and by age- and gender-matched, normally fluent control participants.
The results did not support these hypotheses. The results showed that although there were significantly fewer PIs in the speech of the speakers who stuttered (probably because of their slower speaking rate), there was no significant difference between the PI distributions of both speaker groups. This was also true for comparisons between the stutter-free speech of the affected speakers and matched periods of speech produced by the control participants. The PI distributions from both groups were highly correlated.
The null hypothesis findings are discussed in relation to speech-motor- and neurologic-systems explanations for the fluency-inducing effects of reducing short PIs in the speech of individuals who stutter.
Journal of Speech Language and Hearing Research 03/2006; 49(1):161-71. · 1.88 Impact Factor
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ABSTRACT: This article critically reviews evidence to determine whether the use of disfluency typologies, such as syllable repetitions or prolongations, has assisted the understanding or treatment of developmental stuttering. Consideration is given to whether there is a need for a fundamental shift in the basis for constructing measures of stuttering behavior.
The history of using specific types of disfluencies to assess stuttering, including more recent developments such as counts of stuttering-like disfluencies, is reviewed. The focus is on studies that have investigated the validity and reliability of these perceptually based assessment methods.
The evidence from use of disfluency-type measures shows that the behavioral difference between stuttering and normally fluent speakers is solely related to the amount of observable stuttering; the differences are only partially realized within disfluency-type measures. Indeed, because disfluency-type measures show poor reliability and conflate stuttered and nonstuttered speech, they have only limited heuristic value for research and provide no obvious benefits for clinicians. At best, they should be regarded as imprecise descriptors of observable stuttering and not a fundamental measure of stuttering. A recommended solution to the problematic history of verbal-based definitions of stuttering behavior is continued development and investigation of exemplar-based definition and measurement.
American Journal of Speech-Language Pathology 12/2005; 14(4):260-73. · 2.03 Impact Factor
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Journal of Speech Language and Hearing Research 11/2005; 48(5):1025-8; author reply 1029-32. · 1.88 Impact Factor
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ABSTRACT: This study reports an activation likelihood estimation (ALE) meta-analysis of imaging studies of chronic developmental stuttering in adults. Two parallel meta-analyses were carried out: (1) stuttered production in the stutterers; (2) fluent production in the control subjects. The control subjects' data replicated previous analyses of single-word reading, identifying activation in primary motor cortex, premotor cortex, supplementary motor area, Rolandic operculum, lateral cerebellum, and auditory areas, among others. The stuttering subjects' analysis showed that similar brain areas are involved in stuttered speech as in fluent speech, but with some important differences. Motor areas were over-activated in stuttering, including primary motor cortex, supplementary motor area, cingulate motor area, and cerebellar vermis. Frontal operculum, Rolandic operculum, and anterior insula showed anomalous right-laterality in stutterers. Auditory activations, due to hearing one's own speech, were essentially undetectable in stutterers. The phenomenon of efference copy is proposed as a unifying account of the pattern activation revealed within this ALE meta-analysis. This provides the basis for a stuttering system model that is testable and should help to advance the understanding and treatment of this disorder.
Human Brain Mapping 06/2005; 25(1):105-17. · 5.88 Impact Factor
