Perisylvian sulcal morphology and cerebral asymmetry patterns in adults who stutter.

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.

Does language influence the accuracy of judgments of stuttering in children?

PURPOSE: To determine whether stuttering judgment accuracy is influenced by familiarity with the stuttering speaker's language. METHOD: 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. RESULTS: 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. CONCLUSION: 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.

Evidence-based treatment and stuttering--historical perspective.

PURPOSE: To illustrate the way in which both fluency shaping (FS) and stuttering management (SM) treatments for developmental stuttering in adults are evidence based. METHOD: 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. CONCLUSION: 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.

Measurement of speech effort during fluency-inducing conditions in adults who do and do not stutter.

PURPOSE: 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. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.

Stuttering treatment and brain research in adults: A still unfolding relationship.

PURPOSE: Brain imaging and brain stimulation procedures have now been used for more than two decades to investigate the neural systems that contribute to the occurrence of stuttering in adults, and to identify processes that might enhance recovery from stuttering. The purpose of this paper is to review the extent to which these dual lines of research with adults who stutter have intersected and whether they are contributing towards the alleviation of this impairment. METHOD: Several areas of research are reviewed in order to determine whether research on the neurology of stuttering is showing any potential for advancing the treatment of this communication disorder: (a) attempts to discover the neurology of stuttering, (b) neural changes associated with treated recovery, and (c) direct neural intervention. RESULTS AND CONCLUSIONS: Although much has been learned about the neural underpinnings of stuttering, little research in any of the reviewed areas has thus far contributed to the advancement of stuttering treatment. Much of the research on the neurology of stuttering that does have therapy potential has been largely driven by a speech-motor model that is designed to account for the efficacy of fluency-inducing strategies and strategies that have been shown to yield therapy benefits. Investigations on methods that will induce neuroplasticity are overdue. Strategies profitable with other disorders have only occasionally been employed. However, there are signs that investigations on the neurology of adults who have recovered from stuttering are slowly being recognized for their potential in this regard.

Yaruss, Coleman, and Hammer (2006): an exemplar of non-evidence-based practice in stuttering treatment.

PURPOSE: This letter is a response to a recent report by J. S. Yaruss, C. Coleman, and D. Hammer (2006) that described a treatment program for preschool children who stutter. CONCLUSION: Problems with the Yaruss et al. study fall into four domains: (a) failure to provide clinicians with replicable procedures, (b) failure to collect valid and reliable speech performance data, (c) failure to control for predictable improvement in children who have been stuttering for less than 15 months, and (d) the advocacy of procedures for which there is no credible research evidence. The claims made for the efficacy of this treatment are problematic and essentially violate the principles of evidence-based practice as recommended by the American Speech-Language-Hearing Association (ASHA).

Putting the cart before the horse: A cost effectiveness analysis of treatments for stuttering in young children requires evidence that the treatments analyzed were effective.

PURPOSE: To investigate the validity of findings from a recent study reported in this journal by de Sonneville-Koedoot, Bouwmans, Franken, and Stolk (2015) on the cost effectiveness of two programs for treating young children who stutter. METHODS: The de Sonneville-Koedoot, Bouwmans et al. study was based directly on the results obtained in an earlier study, known as the RESTART-study, which compared the outcomes from the Lidcombe Program and a Demands and Capacities Model program. The methodology of the RESTART-study was critically reviewed. RESULTS: The absence of an untreated control group in the RESTART-study makes the results of that study uninterpretable. An inappropriate comparison made with the Yairi and Ambrose (2005) Illinois Study findings failed to resolve the control group problem. Furthermore, the criteria used to classify treated children as "non-stuttering" was also shown to be confounded. The foregoing problems meant that neither treatment program could be shown to be more effective than no treatment. CONCLUSION: de Sonneville-Koedoot, Bouwmans et al's findings, which compared the cost effectiveness of two treatments for young children who stutter, have no value for clinical management because the treatments investigated were not shown to be more effective than no treatment.

Speech effort measurement and stuttering: investigating the chorus reading effect.

PURPOSE: 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. METHOD: 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. RESULTS: 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. CONCLUSION: 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.

The distribution of phonated intervals in the speech of individuals who stutter.

PURPOSE: 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. METHOD: 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. RESULTS: 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. CONCLUSION: 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.

Stuttering treatment research 1970-2005: I. Systematic review incorporating trial quality assessment of behavioral, cognitive, and related approaches.

PURPOSE: 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. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.

Stuttering treatment research 1970-2005: II. Systematic review incorporating trial quality assessment of pharmacological approaches.

PURPOSE: 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. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.

"Roadblocks" revisited: neural change, stuttering treatment, and recovery from stuttering.

UNLABELLED: In light of emerging findings concerning untreated recovery and neural plasticity, this paper re-examines the viability of an NIH conference recommendation [Cooper, J. A. (1990). Research directions in stuttering: Consensus and conflict. In Cooper, J. A. (Ed.), Research needs in stuttering: Roadblocks and future directions (pp. 98-100). Rockville, MD: American Speech-Language-Hearing Association.] that adults who have recovered from stuttering might inform our understanding of the nature and treatment of persistent stuttering. It is suggested that those who have recovered could constitute a behavioral, cognitive, and neurophysiologic benchmark for evaluating stuttering treatment for adolescents and adults, while helping to identify the limits of recovery from a persistent disorder. This possibility seems especially promising because of findings from recent studies investigating untreated recovery during childhood and adulthood, the emerging evidence concerning neural plasticity and reorganization, and reports of neural system changes during stuttering treatment. Potential obstacles to applying findings from unassisted recovery to treatment do exist, but the benefits of attempts to fully understand stuttering certainly outweigh the difficulties. EDUCATIONAL OBJECTIVES: After completing this activity, the learner will be able to: (1) describe two complexities involved in determining whether recovery from stuttering was assisted or unassisted; (2) discuss the implications for stuttering research of two neural plasticity research findings from areas other than stuttering; and (3) evaluate the possible implications for stuttering treatment of a coordinated research program that addresses behavioral, cognitive, and neurological characteristics of assisted and unassisted recovery from stuttering.

Have disfluency-type measures contributed to the understanding and treatment of developmental stuttering?

PURPOSE: 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. METHOD: 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. CONCLUSION: 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.

Anomalous white matter morphology in adults who stutter.

AIMS: Developmental stuttering is now generally considered to arise from genetic determinants interacting with neurologic function. Changes within speech-motor white matter (WM) connections may also be implicated. These connections can now be studied in great detail by high-angular-resolution diffusion magnetic resonance imaging. Therefore, diffusion spectrum imaging was used to reconstruct streamlines to examine white matter connections in people who stutter (PWS) and in people who do not stutter (PWNS). METHOD: WM morphology of the entire brain was assayed in 8 right-handed male PWS and 8 similarly aged right-handed male PWNS. WM was exhaustively searched using a deterministic algorithm that identifies missing or largely misshapen tracts. To be abnormal, a tract (defined as all streamlines connecting a pair of gray matter regions) was required to be at least one 3rd missing, in 7 out of 8 subjects in one group and not in the other group. RESULTS: Large portions of bilateral arcuate fasciculi, a heavily researched speech pathway, were abnormal in PWS. Conversely, all PWS had a prominent connection in the left temporo-striatal tract connecting frontal and temporal cortex that was not observed in PWNS. CONCLUSION: These previously unseen structural differences of WM morphology in classical speech-language circuits may underlie developmental stuttering.

Efficacy of the Modifying Phonation Intervals (MPI) Stuttering Treatment Program With Adults Who Stutter.

PURPOSE: This study compared a new adult stuttering treatment program (Modifying Phonation Intervals, or MPI) with the standard of care for reducing stuttered speech in adults (prolonged speech). METHOD: Twenty-seven adults who stutter were assigned to either MPI or prolonged speech treatment, both of which used similar infrastructures. Speech and related variables were assessed in 3 within-clinic and 3 beyond-clinic speaking situations for participants who successfully completed all treatment phases. RESULTS: At transfer, maintenance, and follow-up, the speech of 14 participants who successfully completed treatment was similar to that of normally fluent adults. Successful participants also showed increased self-identification as a "normal speaker," decreased self-identification as a "stutterer," reduced short intervals of phonation, and some increased use of longer duration phonation intervals. Eleven successful participants received the MPI treatment, and 3 received the prolonged speech treatment. CONCLUSIONS: Outcomes for successful participants were very similar for the 2 treatments. The much larger proportion of successful participants in the MPI group, however, combined with the predictive value of specific changes in PI durations suggest that MPI treatment was relatively more effective at assisting clients to identify and change the specific speech behaviors that are associated with successful treatment of stuttered speech in adults.

The efficacy of stuttering measurement training: evaluating two training programs.

PURPOSE: Two stuttering measurement training programs currently used for training clinicians were evaluated for their efficacy in improving the accuracy of total stuttering event counting. METHOD: Four groups, each with 12 randomly allocated participants, completed a pretest-posttest design training study. They were evaluated by their counts of stuttering events on eight 3-min audiovisual speech samples from adults and children who stutter. Stuttering judgment training involved use of either the Stuttering Measurement System (SMS), Stuttering Measurement Assessment and Training (SMAAT) programs, or no training. To test for the reliability of any training effect, SMS training was repeated with the 4th group. RESULTS: Both SMS-trained groups produced approximately 34% improvement, significantly better than no training or the SMAAT program. The SMAAT program produced a mixed result. CONCLUSIONS: The SMS program was shown to produce a "medium" effect size improvement in the accuracy of stuttering event counts, and this improvement was almost perfectly replicated in a 2nd group. Half of the SMAAT judges produced a 36% improvement in accuracy, but the other half showed no improvement. Additional studies are needed to demonstrate the durability of the reported improvements, but these positive effects justify the importance of stuttering measurement training.

Brain correlates of stuttering and syllable production: gender comparison and replication.

This article reports a gender replication study of the P. T. Fox et al. (2000) performance correlation analysis of neural systems that distinguish between normal and stuttered speech in adult males. Positron-emission tomographic (PET) images of cerebral blood flow (CBF) were correlated with speech behavior scores obtained during PET imaging for 10 dextral female stuttering speakers and 10 dextral, age- and sex-matched normally fluent controls. Gender comparisons were made between the total number of voxels per region significantly correlated with speech performance (as in P. T. Fox et al., 2000) plus total voxels per region that were significantly correlated with stutter rate and not with syllable rate. Stutter-rate regional correlates were generally right-sided in males, but bilateral in the females. For both sexes the positive regional correlates for stuttering were in right (R) anterior insula and the negative correlates were in R Brodmann area 21/22 and an area within left (L) inferior frontal gyrus. The female stuttering speakers displayed additional positive correlates in L anterior insula and in basal ganglia (L globus pallidus, R caudate), plus extensive right hemisphere negative correlates in the prefrontal area and the limbic and parietal lobes. The male stuttering speakers were distinguished by positive correlates in L medial occipital lobe and R medial cerebellum. Regions that positively correlated with syllable rate (essentially stutter-free speech) in stuttering speakers and controls were very similar for both sexes. The findings strengthen claims that chronic developmental stuttering is functionally related to abnormal speech-motor and auditory region interactions. The gender differences may be related to differences between the genders with respect to susceptibility (males predominate) and recovery from chronic stuttering (females show higher recovery rates during childhood).

Towards a functional neural systems model of developmental stuttering.

UNLABELLED: This paper overviews recent developments in an ongoing program of brain imaging research on developmental stuttering that is being conducted at the University of Texas Health Science Center, San Antonio. This program has primarily used H(2)15O PET imaging of different speaking tasks by right-handed adult male and female persistent stutterers, recovered stutterers and controls in order to isolate the neural regions that are functionally associated with stuttered speech. The principal findings have emerged from studies using condition contrasts and performance correlation techniques. The emerging findings from these studies are reviewed and referenced to a neural model of normal speech production recently proposed by Jürgens [Neurosci. Biobehav. Rev. 26 (2002) 235]. This paper will report (1) the reconfiguration of previous findings within the Jürgens Model; (2) preliminary findings of an investigation with late recovered stutterers; (3) an investigation of neural activations during a treatment procedure designed to produce a sustained improvement in fluency; and (4) an across-studies comparison that seeks to isolate neural regions within the Jürgens Model that are consistently associated with stuttering. Two regions appear to meet this criterion: right anterior insula (activated) and anterior middle and superior temporal gyri (deactivated) mainly in right hemisphere. The implications of these findings and the direction of future imaging investigations are discussed. EDUCATIONAL OBJECTIVES: The reader will learn about (1) recent uses of H(2)15O PET imaging in stuttering research; (2) the use of a new neurological model of speech production in imaging research on stuttering; and (3) initial findings from PET imaging investigations of treated and recovered stutterers.

The effect of speech rate on stuttering frequency, phonated intervals, speech effort, and speech naturalness during chorus reading.

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 32 years. 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.