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Purpose: The purpose of this study was to test whether adults who stutter (AWS) display a different range of sensitivity to delayed auditory feedback (DAF). Two experiments were conducted to assess the fluency of AWS under long-latency DAF and to test the effect of short-latency DAF on speech kinematic variability in AWS. Method: In Experiment 1,15 AWS performed a conversational speaking task under nonaltered auditory feedback and 250-ms DAF. The rates of stuttering-like disfluencies, other disfluencies, and speech errors and articulation rate were compared. In Experiment 2, 13 AWS and 15 adults who do not stutter (AWNS) read three utterances under four auditory feedback conditions: nonaltered auditory feedback, amplified auditory feedback, 25-ms DAF, and 50-ms DAF. Across-utterance kinematic variability (spatiotemporal index) and within-utterance variability (percent determinism and stability) were compared between groups. Results: In Experiment 1, under 250-ms DAF, the rate of stuttering-like disfluencies and speech errors increased significantly, while articulation rate decreased significantly in AWS. In Experiment 2, AWS exhibited higher kinematic variability than AWNS across the feedback conditions. Under 25-ms DAF, the spatiotemporal index of AWS decreased significantly compared to the other feedback conditions. AWS showed lower overall percent determinism than AWNS, but their percent determinism increased under 50-ms DAF to approximate that of AWNS. Conclusions: Auditory feedback manipulations can alter speech fluency and kinematic variability in AWS. Longer latency auditory feedback delays induce speech disruptions, while subtle auditory feedback manipulations potentially benefit speech motor control. Both AWS and AWNS are susceptible to auditory feedback during speech production, but AWS appear to exhibit a distinct continuum of sensitivity., The relationship between sensorimotor integration and speech production is a central issue in the search for the cause of stuttering and for delivering innovative intervention. There has been a consensus [...]

Purpose: The purpose of this study was to examine the verbal short-term memory skills of children who stutter (CWS) and children who do not stutter (CWNS) in 2 experiments, focusing on the influence of phonological and semantic similarity. Method: Participants were 42 CWS and 42 CWNS between the ages of 3;0 and 5;11 (years;months). In Experiment 1, children completed the phonological similarity task, in which they listened to lists of phonologically similar and dissimilar words and then repeated them when signaled to do so. In Experiment 2, children completed another forward span task, the semantic category task, which is similar to the phonological similarity task, except that it consisted of lists of semantically homogeneous and heterogeneous words. Main dependent variables were cumulative memory span, proportion of errors by type, and speech reaction time (SRT) for correct responses. Results: The CWS exhibited significantly shorter memory spans for phonologically dissimilar words and were less affected by the phonological qualities of the words than the CWNS in Experiment 1, based on the findings of both between-groups and within-group analyses. In Experiment 2, although the groups did not differ in their performance in either condition, within-group analyses revealed that the CWNS benefitted from semantic similarity, whereas the CWS did not. The between-groups difference in absolute difference scores, however, did not reach significance. The CWS produced more omissions and false alarms than the CWNS in both experiments, but the 2 groups of children were otherwise comparable in SRT, although the CWS exhibited overall faster SRT than the CWNS in Experiment 2. Conclusions: Verbal short-term memory is one domain-general cognitive process in which CWS display weakness relative to typically fluent peers. These weaknesses are likely due, in part, to differences in phonological and, perhaps, semantic processing of words to aid memory., To date, there is a robust literature focusing on differences between children who stutter (CWS) and children who do not stutter (CWNS) in their language skills, particularly during the preschool [...]

Purpose: The perception of rhythm cues plays an important role in recognizing spoken language, especially in adverse listening conditions. Indeed, this has been shown to hold true even when the rhythm cues themselves are dysrhythmic. This study investigates whether expertise in rhythm perception provides a processing advantage for perception (initial intelligibility) and learning (intelligibility improvement) of naturally dysrhythmic speech, dysarthria. Method: Fifty young adults with typical hearing participated in 3 key tests, including a rhythm perception test, a receptive vocabulary test, and a speech perception and learning test, with standard pretest, familiarization, and posttest phases. Initial intelligibility scores were calculated as the proportion of correct pretest words, while intelligibility improvement scores were calculated by subtracting this proportion from the proportion of correct posttest words. Results: Rhythm perception scores predicted intelligibility improvement scores but not initial intelligibility. On the other hand, receptive vocabulary scores predicted initial intelligibility scores but not intelligibility improvement. Conclusions: Expertise in rhythm perception appears to provide an advantage for processing dysrhythmic speech, but a familiarization experience is required for the advantage to be realized. Findings are discussed in relation to the role of rhythm in speech processing and shed light on processing models that consider the consequence of rhythm abnormalities in dysarthria., Speech rhythm, broadly defined herein as recurring spectral-temporal patterns within the acoustic signal, functions, universally, to reduce the computational load of recognizing spoken language. As summarized by Liss, Utianski, and [...]

Purpose: This study examined the impact of social-cognitive stress on sentence-level speech variability, determinism, and stability in adults who stutter (AWS) and adults who do not stutter (AWNS). We demonstrated that complementing the spatiotemporal index (STI) with recurrence quantification analysis (RQA) provides a novel approach to both assessing and interpreting speech variability in stuttering. Method: Twenty AWS and 21 aWnS repeated sentences in audience and nonaudience conditions while their lip movements were tracked. Across-sentence variability was assessed via the STI; within-sentence determinism and stability were assessed via RQA. Results: Compared with the AWNS, the AWS produced speech that was more variable across sentences and more deterministic and stable within sentences. Audience presence contributed to greater within-sentence determinism and stability in the AWS. A subset of AWS who were more susceptible to experiencing anxiety exhibited reduced across-sentence variability in the audience condition compared with the nonaudience condition. Conclusions: This study extends the assessment of speech variability in AWS and AWNS into the social-cognitive domain and demonstrates that the characterization of speech within sentences using RQA is complementary to the across-sentence STI measure. AWS seem to adopt a more restrictive, less flexible speaking approach in response to social-cognitive stress, which is presumably a strategy for maintaining observably fluent speech., Persistent developmental stuttering (herein referred to simply as stuttering) is a communication disorder thought to emerge from a complex interaction of linguistic, cognitive, motor, and/or environmental processes (Alm, 2014; Smith [...]

Purpose: The study examined whether semantic and phonological encoding processes were capacity demanding, involving the central cognitive mechanism, in adults who do and do not stutter (AWS and NS) to better understand the role of cognitive demand in linguistic processing and stuttering. We asked (a) whether the two linguistic processes in AWS are capacity demanding, which can temporally disrupt the processing of a concurrent nonlinguistic task, and (b) whether AWS and NS show similar patterns of temporal disruption in the two processes. Method: Twenty AWS and 20 matched NS participated in the study. We examined semantic interference and phonological facilitation effects, using the picture-word interference paradigm, under concurrent and sequential processing of a secondary, nonlinguistic task. Results: Both AWS and Ns showed statistically significant semantic interference and phonological facilitation effects, and both effects caused temporal disruption to the processing of a secondary task to the predicted extent. Conclusions: The observed result patterns in both AWS and NS suggest that both semantic and phonological encoding processes are capacity demanding and can be vulnerable to concurrent processing demands. This finding on NS is inconsistent with the current literature on young, fluent adults and warrants further investigation., The disruptions of speech flow in stuttering have led a large body of researchers to examine the potential processes underlying speech-language production in people who stutter (PWS). There is consensus [...]

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., The cause of developmental stuttering is still unknown, but it is generally considered to arise from a combination of genetic factors and subsequent alterations of neurologic function (Bloodstein & Ratner, [...]

Purpose: Stuttering varies between and within speaking situations. In this study, the authors used statistical process control charts with 10 case studies to investigate variability of stuttering frequency. Method: Participants were 10 adults who stutter. The authors counted the percentage of syllables stuttered (%SS) for segments of their speech during different speaking activities over a 12-hr day. Results for each participant were plotted on control charts. Results: All participants showed marked variation around mean stuttering frequency. However, there was no pattern of that variation consistent across the 10 participants. According to control charts, the %SS scores of half the participants were indicative of unpredictable, out-of-control systems, and the %SS scores of the other half of the participants were not. Self-rated stuttering severity and communication satisfaction correlated significantly and intuitively with the number of times participants exceeded their upper control chart limits. Conclusions: Control charts are a useful method to study how %SS scores might be applied to the study of stuttering variability during research and clinical practice. However, the method presents some practical problems, and the authors discuss how those problems can be solved. Solving those problems would enable researchers and clinicians to better plan, conduct, and evaluate stuttering treatments. Key Words: stuttering, variability, statistical process control chart, percent syllables stuttered, It is commonly recognized that the stuttering frequency of individual speakers varies (Andrews et al., 1983; Bloodstein & Bernstein Ratner, 2008; Van Riper, 1971; Yaruss, 1997). Evidence for that belief [...]

Purpose: Individuals who stutter show sensorimotor deficiencies in speech and nonspeech movements. For the mandibular system, the authors dissociated the sense of kinesthesia from the efferent control component to examine whether kinesthetic integrity itself is compromised in stuttering or whether deficiencies occur only when generating motor commands. Method: The authors investigated 11 stuttering and 11 nonstuttering adults' kinesthetic sensitivity threshold and kinesthetic accuracy for passive jaw movements as well as their minimal displacement threshold and positioning accuracy for active jaw movements. They also investigated the correlation with an anatomical index of jaw size. Results: The groups showed no statistically significant differences on sensory measures for passive jaw movements. Although some stuttering individuals performed more poorly than any nonstuttering participants on the active movement tasks, between-group differences for active movements were not statistically significant. Unlike fluent speakers, however, the stuttering group showed a statistically significant correlation between mandibular size and performance in the active and passive near-threshold tasks. Conclusions: Previously reported minimal-movement differences were not replicated. Instead, stuttering individuals' performance varied with anatomical properties. These correlational results are consistent with the hypothesis that stuttering participants generate and perceive movements on the basis of less accurate internal models of the involved neuromechanical systems. Key Words: stuttering, sensorimotor control, kinesthesia, movement planning, internal model, Converging evidence from various lines of research provides compelling support for the hypothesis that stuttering may be related to deficiencies in fundamental sensorimotor processes. For example, neuroimaging data have revealed [...]

Purpose: In individuals who stutter (IWS), speech fluency can be enhanced by altered auditory feedback, although it has adverse effects in control speakers. This indicates abnormalities in the auditory feedback loop in stuttering. Current motor control theories on stuttering propose an impaired processing of internal forward models that might be related to a blurred auditory-to-motor translation. Although speech sound perception is an essential skill to form internal models, perceptual acuity has not been studied in IWS so far. The authors tested the stability of phoneme percepts by analyzing participants' ability to identify voiced and voiceless stop consonants. Method: Two syllable continua were generated by systematic modification of the voice onset time. The authors determined speech perceptual acuity by means of discriminatory power in 25 IWS and 24 matched control participants by determining the phoneme boundaries and by quantifying the interval of voice onset times for which phonemes were perceived ambiguously. Results: In IWS, discriminatory performance was weaker and less stable over time when compared with control participants. In addition, phoneme boundaries were located at longer voice onset times in IWS. Conclusion: Persistent developmental stuttering is associated with less reliable phonological percepts, supporting current theories regarding the sensory--motor interaction in human speech. Key Words: phoneme categorization, speech perception, stuttering, voice onset time, Stuttering is characterized by sudden interruptions of fluent speech that are due to an intermittent loss of motor control (Ludlow & Loucks, 2003). The dynamic, multifactorial view of stuttering postulates [...]

Purpose: This study introduces a series of systematic investigations intended to clarify the parameters of the fluency-inducing conditions (FICs) in stuttering. Method: Participants included 11 adults, aged 20-63 years, with typical speech-production skills. A repeated measures design was used to examine the relationships between several speech production variables (vowel duration, voice onset time, fundamental frequency, intraoral pressure, pressure rise time, transglottal airflow, and phonated intervals) and speech rate and instatement style during metronome-entrained rhythmic speech. Results: Measures of duration (vowel duration, voice onset time, and pressure rise time) differed across different metronome conditions. When speech rates were matched between the control condition and metronome condition, voice onset time was the only variable that changed. Conclusion: Results confirm that speech rate and instatement style can influence speech production variables during the production of fluency-inducing conditions. Future studies of normally fluent speech and of stuttered speech must control both features and should further explore the importance of voice onset time, which may be influenced by rate during metronome stimulation in a way that the other variables are not. KEY WORDS: stuttering, fluency-inducing conditions, vocalization, rhythmic speech, Wingate's (1969,1970) influential modified vocalization hypothesis postulated that fluency-inducing conditions (FICs) are successful at reducing stuttering because 'the stutterer is induced to emphasize phonation and continuity of phonation in the [...]

Purpose: The purpose of this study was to determine whether the underlying temperamental structure of the Dutch Children's Behavior Questionnaire (CBQ; B. Van den Bergh & M. Ackx, 2003) was identical for children who stutter (CWS), typically developing children (TDC), and children with vocal nodules (CWVN). Method: A principal axis factor analysis was performed on data obtained with the Dutch CBQ from 69 CWS, 149 TDC, and 41 CWVN. All children were between the ages of 3;0 (years; months) and 8;11. Results: Results indicated a 3-factor solution, identified as Extraversion/Surgency, Negative Affect, and Effortful Control, for each of the participant groups, showing considerable similarity to previously published U.S., Chinese, Japanese, and Dutch samples. Congruence coefficients were highest for CWS and TDC and somewhat more modest when comparing CWVN and TDC. The Effortful Control factor consistently yielded the lowest congruence coefficients. Conclusion: These data confirm that although stuttering, voice-disordered, and typically developing children may differ quantitatively with regard to mean scores on temperament scales, they are similar in terms of their overall underlying temperament structure. The equivalence of temperament structure provides a basis for further comparison of mean group scores on the individual temperament scales. KEY WORDS: stuttering, voice disorders, normal speech, temperament, Children's Behavior Questionnaire, The temperament model by Rothbart and Derryberry (Derryberry & Rothbart, 1984; Rothbart & Derryberry, 1981), developed in the early 1980s, has received widespread attention in the scientific literature on child [...]

Fluency-enhancing speech feedback, originating from internally or externally generated sources via auditory or visual sensory modalities is not restricted to a specific sensory modality or signal origination. Research suggests that externally generated digital vibrotactile speech feedback serves as an effective fluency enhancer. The present purpose was to test the fluency-enhancing effects of self-generated digital vibrotactile speech feedback on stuttering frequency. Adults who stutter read passages aloud over the telephone, both with and without digital vibrotactile speech feedback. Digital vibrotactile speech feedback was operationally defined as feeling the vibrations of the thyroid cartilage with the thumb and index finger while speaking. Analysis indicated that self-generated digital vibrotactile speech feedback reduced overt stuttering frequency by an average of 72%. As the specific neural mechanisms associated with stuttering and fluency enhancement from tactile speech feedback remain unknown, theoretical implications and clinical applications were discussed.

Purpose: The aims of the present study were to (a) examine the rate of social phobia among adults who stutter, (b) study the effects of speech restructuring treatment on social [...]

Purpose: The purpose of this study was to examine the influence of phonotactic probability, which is the frequency of different sound segments and segment sequences, on the overall fluency with [...]

Models of interhemispheric interference have been proposed as an explanation for the cause and maintenance of stuttering. One component of this model is attentional functioning and allocation. This study examined [...]

Purpose: The purpose of this study was to examine (a) the role of neighborhood density (number of words that are phonologically similar to Q target word) and frequency variables on the stuttering-like disfluencies of preschool children who stuffer, and (b) whether these variables have an effect on the type of stuttering-like disfluency produced. Method: A 500+ word speech sample was obtained from each participant (N = 15). Each stuttered word was randomly paired with the firstly produced word that closely matched it in grammatical class, familiarity, and number of syllables/phonemes. Frequency, neighborhood density, and neighborhood frequency values were obtained for the stuttered and fluent words from an online database. Results: Findings revealed that stuttered words were lower in frequency and neighborhood frequency than fluent words. Words containing part-word repetitions and sound prolongations were also lower in frequency and/or neighborhood frequency than fluent words, but these frequency variables did not have an effect on single-syllable word repetitions. Neighborhood density failed to influence the susceptibility of words to stuttering, as well as the type of stuttering-like disfluency produced. Conclusions: In general, findings suggest that neighborhood and frequency variables not only influence the fluency with which words are produced in speech, but also have an impact on the type of stuttering-like disfluency produced. KEY WORDS: stuttering, language, phonological neighborhood, frequency, children, A number of linguistic factors have been shown to have an impact on the fluency with which words are produced in speech. For example, older children and adults who stutter [...]

Purpose: The purpose of this study was to investigate whether lexical access in adults who stutter (AWS) differs from that in people who do not stuffer. Specifically, the authors examined the role of 3 lexical factors on naming speed, accuracy, and fluency: word frequency, neighborhood density, and neighborhood frequency. If stuttering results from an impairment in lexical access, these factors were hypothesized to differentially affect AWS performance on a confrontation naming task. Method: Twenty-five AWS and 25 normally fluent comparison speakers, matched for" age and education, participated in a confrontation naming task designed to explore within-speaker performance on naming accuracy, speed, and fluency based on stimulus word frequency and neighborhood characteristics. Accuracy, fluency, and reaction time (from acoustic waveform analysis) were computed. Results: In general, AWS demonstrated the same effects of lexical factors on their naming as did adults who do not stutter. However, accuracy of naming was reduced for AWS. Stuttering rate was influenced by word frequency but not other factors. Conclusions: Results suggest that AWS could have a fundamental deficit in lexical retrieval, but this deficit is unlikely to be at the level of the word's abstract phonological representation. Implications for further research are discussed. KEY WORDS: stuttering, lexical access, naming, Although the underlying causes of stuttering are not known, there are a number of linguistic regularities that characterize stutter events in both adults and children (see Bernstein Ratner, 1997, for [...]

Purpose: The purpose of this study was to develop guidelines for the statistical analysis of percentage of syllables stuttered (%SS) data in stuttering research. Method: Data on %SS from various independent sources were used to develop a statistical model to describe this type of data. On the basis of this model, %SS data were simulated with varying means, standard deviations, and sample sizes. Four methods for analyzing %SS were compared. Results: Results suggested that %SS data can be adequately modeled with a gamma distribution. Simulations based on a gamma distribution showed that all 4 analysis techniques performed favorably with respect to Type I error except for F. E. Satterthwaite's (1946) t test, which had increased Type I error on two occasions. Power was generally lower for the Wilcoxon-Mann-Whitney test compared with the other methods. Analysis of variance (ANOVA) performed on square-root-transformed data performed adequately under all scenarios, but ANOVA performed on nontransformed data and Satterthwaite's t test performed poorly when sample sizes were small or when sample sizes and variances of the groups were markedly different. Conclusions: Standard techniques such as t test and ANOVA are appropriate for most analysis scenarios with %SS data. Two occasions when this is not the case are when sample size is small, with fewer than 20 in each group, or when sample sizes and variances of the groups are markedly different. Under these circumstances, analyses should be based on standard methods, with a suitable transformation performed prior to analysis. KEY WORDS: stuttering, statistical analysis, percentage of syllables stuttered, power, Type I error, gamma distribution, transformation, Behavioral measures of stuttering are essential when establishing the severity of the disorder for research. Severity measures that are based on counts of stuttering are informative because they reflect the [...]

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. KEY WORDS: stuttering, speech effort, chorus reading, speech naturalness, The characteristics of normally fluent speech are not easily defined. Nevertheless, few people would dispute that the concept of normally fluent speech incorporates (a) relatively little disfluency, (b) a normal [...]

Purpose: The purpose of this study was to examine and compare the development of proto-imperative and proto-declarative utterances in normally developing, non-neonatally screened, profoundly deaf toddlers. Method: Both types of proto-declarative are considered to be the most basic prelinguistic and early linguistic communicative functions. Eighteen normally developing, non-neonatally screened, profoundly deaf toddlers participated in a longitudinal study. All children were enrolled in the same oral-aural home guidance program. At the time of the study, none of the children had received a cochlear implant. At the ages of 18, 24, and 30 months, proto-imperative utterances were elicited using an adapted version of M. Casby and J. A. Cumpata's (1986) Protocol for the Assessment of Prelinguistic Intentional Communication. For eliciting proto-declarative intentions, a video clip was used. Results: Results revealed a significant increase in both frequency and level of utterances for both types of proto-performatives. Although there was a clear development from nonlinguistic toward linguistic communication, utterances remained predominantly deictic-gestural for the imperative intentions and referential-gestural for declaratives. Conclusions: The data support the notion from the literature that both types of performatives are susceptible to elicitation. Results also suggest that after neonatal screening, both total communication and oral-aural approaches might accelerate conventionalization of the earliest communicative utterances of profoundly deaf toddlers. KEY WORDS: deaf, proto-performative, prelinguistic, Thus far, most studies of pragmatic functions of deaf toddlers have focused an the range of deaf children's communicative intention compared with hearing children. Young deaf children seem to express [...]

ABSTRACT. The current study was based on the hypothesis that chronic developmental stuttering in adults involves a deficiency in oral kinesthesia. The authors used a target-accuracy task to compare oral [...]

A case study of DW, an 11-yr. old monolingual, English-speaking boy who exhibits stuttering, language delay, and ADHD is presented. DW experienced only limited improvement during stuttering therapy received in public schools, according to parents and the public school clinician. The purpose of this case study was to assess whether fluency treatment which incorporated Mediated Learning, Delayed Auditory Feedback, and Speech Motor Repatterning would enhance progress. Therapy was delivered in two treatments, with each treatment being 5 wk. of intense therapy, separated by one year. Treatment 1 of combined Mediated Learning and Delayed Auditory Feedback yielded improvement in fluency, judged by parents and the teacher to be clinically significant. The improved fluency was maintained for one year when DW was pretested for participation in Treatment 2, which combined Mediated Learning, Delayed Auditory Feedback, and Speech Motor Repatterning Exercises. A no conclusions are possible, further study is needed.

This study explored the effect of reading with reversed speech on the frequency of stuttering. Eight adults who stutter served as participants and read four 300-syllable passages while listening to three types of speech stimuli: normal speech (choral reading), reversed speech at normal speed, reversed speech at half speed, and a control condition of no auditory feedback. A repeated-measures analysis of variance showed a significant decrease in stuttering frequency in the choral reading condition but not in reversed speech at normal and half speed. However, the reversed speech at half-speed condition showed a large effect size ([[omega].sup.2] = 0.32). Data suggest that a forward moving speech feedback is not essential to decrease the frequency of stuttering in adults who stutter.

The purpose of this investigation was to assess the influence of lexical/semantic priming on the speech reaction time of young children who do and do not stutter during a picture-naming task. Participants were 23 children who stutter, age-matched ([+ or -] 4 months) to 23 children who do not stutter, ranging in age from 3;0 (years;months) to 5;11. Procedures involved a computer-assisted picture-naming task, during which each participant was presented with the same set of 28 pictures in each of 3 different conditions: (a) no-prime condition, in which no auditory stimulus was presented before picture display; (b) related-prime condition, in which a word, semantically related to the target picture, was presented auditorily 700 ms before picture display; and (c) unrelated-prime condition, in which a semantically unrelated word was presented auditorily 700 ms before picture display. Results indicated that when compared with a no-prime condition, presentation of semantically related words before the picture-naming response led to shorter or faster speech reaction times for children who do not stutter, but for children who stutter, it led to longer or slower speech reaction times. Moreover, children who do not stutter and who had higher receptive vocabulary scores exhibited faster speech reaction times and a greater semantic priming effect, whereas no such relationships were found for children who stutter. Findings were taken to suggest that children who stutter may exhibit subtle difficulties with lexical encoding and that this difficulty with speech-language planning may be one variable that contributes to childhood stuttering. KEY WORDS: stuttering, disfluency, preschool, priming, While motoric variables have been extensively studied and reviewed relative to stuttering in children and adults (see Conture, 1991; Ingham, 1998; Max & Caruso, 1997, 1998; McClean, 1997; van Lieshout, [...]

This study investigated the comparative reliability of 2 stuttering measurement tools when used by experienced judges: percentage of syllables stuttered (%SS) and a 9-point severity scale (SEV). The study also investigated the degree to which scores on 1 tool predict scores on the other and the distributions of stuttering when measured by these tools. Twelve experienced judges watched 3-min videotapes of 90 stuttering and 10 nonstuttering participants. Half the judges rated %SS, and half made severity ratings. Results showed very high intrajudge and interjudge agreement for both measures. There was a strong linear correlation between %SS scores and SEV scores. Based on this finding, it seems that the 2 measures can be regarded as largely interchangeable. The exception to this, however, was in cases where there was either a small number of significant fixed postures (blocks and prolongations) or a large number of innocuous repeated movements (repetitions) in the speech sample. In such cases, it appears that %SS and SEV scores combined would be needed to provide a valid measure of stuttering. SEV scores were more normally distributed than %SS scores, which were clearly skewed. The advantages and limitations of the SEV scale are discussed. KEY WORDS: stuttering measurement, rating scales, percentage of syllables stuttered, stuttering distribution, Various methods are used for measuring stuttering, including those based on counts of stuttering events and those based on perceptual judgments of stuttering severity. This report compares two commonly used [...]

Conversation is one of the most fundamental of all human activities. While most people take this form of interaction for granted, people who stammer often approach it with fear and trepidation. This article identifies stammering as a distinctly social event and highlights the relative neglect of the issue within the discipline of sociology. Drawing upon the work of George Mead and Erving Goffman we suggest that a distinctly sociological approach offers specific insights into stammering as an effect of social interaction. We argue that the strategies that people who stammer employ when passing and covering and the accounting practices that all individuals use in social interaction to define the difference between stammered and non-stammered speech are of sociological interest insofar as they provide valuable insights into the interaction of self and society, the tenuous distinction between 'normal' and 'abnormal', and the conceptual boundaries of disability. KEY WORDS passing / self / stammering / stigma / symbolic interactionism

Developmental stuttering is a disorder of speech fluency characterized by the interruption of smooth flow of speech. The disorder typically begins during the early childhood years of rapid linguistic and […]

The purpose of this study was to use an age-appropriate version of the sentence-structure priming paradigm (e.g., K. Bock, 1990; K. Bock, H. Loebell, & R. Morey, 1992) to assess experimentally the syntactic processing abilities of children who stutter (CWS) and children who do not stutter (CWNS). Participants were 16 CWS and 16 CWNS between the ages of 3;3 (years; months) and 5;5, matched for gender and age ([+ or -] 4 months). All participants had speech, language, and hearing development within normal limits, with the exception of stuttering for CWS. All children participated in a sentence-structure priming task where they were shown and asked to describe, on a computer screen, black-on-white line drawings of children, adults, and animals performing activities that could be appropriately described using simple active affirmative declarative (SAAD) sentences (e.g., "The man is walking the dog"). Speech reaction time (SRT) was measured from the onset of the picture presentation to the onset of the child's verbal response in the absence and presence of priming sentences, counterbalanced for order. Main findings indicated that CWS exhibited slower SRTs in the absence of priming sentences and greater syntactic-priming effects than CWNS. These findings suggest that CWS may have difficulty rapidly, efficiently planning and/or retrieving sentence-structure units, difficulties that may contribute to their inabilities to establish fluent speech-language production. KEY WORDS: stuttering, sentence-structure priming, syntactic priming, children, linguistic processing, In recent years, various studies have been conducted regarding the linguistic skills of children who stutter (CWS; for reviews, see Louko, Conture, & Edwards, 1999; Ratner, 1997), as well as [...]

This article reports a gender replication study of the P. T. Fox et a. (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 notwith 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). KEY WORDS: stuttering, brain imaging, gender differences, There is a growing consensus that developmental stuttering is a product of central nervous system dysfunction with genetic origins (see Ingham 2001 Yairi, Ambrose & Cox, 1996). Incomplete left lateralization [...]

This study was intended to replicate and extend previous findings that (a) during fluent speech persons who stutter (PS) and those who do not (NS) differ in their vocal tract closing movements (L. Max, A. J. Caruso, & V. L. Gracco, 2003) and (b) ratios relating lip and tongue speed to jaw speed increase with stuttering severity (M. D. McClean & C. R. Runyan, 2000). An electromagnetic system was used to record movements of the upper lip, lower lip, tongue, and jaw of 43 NS and 37 PS during productions of a nonsense phrase and a sentence. Measurement and analysis of movement speeds, durations, and ratios of lip and tongue speed to jaw speed were performed on fluent productions of a nonsense phrase and sentence. Statistical comparisons were made between PS with low and high stuttering severity levels (LPS and HPS) and NS. Significant variations across groups in movement speed and duration were observed, but the pattern of these effects was complex and did not replicate the results of the two earlier studies. In the nonsense phrase, significant reductions in lower lip closing duration, jaw closing duration, and jaw closing speed were seen in PS. In the sentence task, HPS showed elevated tongue opening and closing durations. For tongue opening in the sentence, LPS showed elevated speeds and HPS showed reduced speeds. The elevated speeds for LPS are interpreted as a contributing factor to speech disfluency, whereas the reduced speeds and increased durations in HPS are attributed to adaptive behavior intended to facilitate fluent speech. Significant group effects were not seen for the speed ratio measures. Results are discussed in relation to multivariate analyses intended to identify subgroups of PS. KEY WORDS: stuttering, orofacial movements, tongue, jaw, lips, Beginning primarily with the investigations of Zimmermann (1980a), there has been a continuing effort to characterize possible differences in the movements underlying the fluent speech of persons who stutter (PS) [...]

The purpose of this study was to assess the influence of phonological priming on the speech reaction time (SRT) of children who do (CWS) and who do not (CWNS) stutter during a picture-naming task. Participants were eighteen 3-5-year-old CWS (M = 50.67 months, SD = 11.83 months), matched in age and gender with 18 CWNS (M = 49.44 months, SD = 10.22 months). The picture-naming task required each child to name, one at a time, computer-presented, white-on-black line drawings of common, age-appropriate objects "as quickly as you can" during 3 different conditions: (a) no prime, (b) related prime, and (c) unrelated prime, with naming latency (alternatively referred to as SRT; in milliseconds) as the main dependent variable. Results indicated that all children exhibited faster or shorter SRTs during the related condition compared to the no prime condition. Similarly, SRT was influenced with advancing age for all children, with 5-year-olds exhibiting faster SRTs than 3-year-olds. Furthermore, CWNS, but not CWS, demonstrated a negative correlation between articulatory mastery and SRT. Findings were taken to suggest that phonological priming is a feasible procedure for studying the speech-language planning and production of 3-5-year-old children and that preschool children who stutter, as a group, may have somewhat less well developed articulatory systems than preschool children who do not stutter. KEY WORDS: stuttering, phonology, priming, children, A considerable amount of research (e.g., Bloodstein, 1995; Cantwell & Baker, 1985; Paden & Yairi, 1996; Paden, Yairi, & Ambrose, 1999; St. Louis & Hinzman, 1988; Throneburg, Yairi, & Paden, [...]

The purpose of this investigation was to assess the temperamental characteristics of children who do (CWS) and do not (CWNS) stutter using a norm-referenced parent-report questionnaire. Participants were 31 CWS and 31 CWNS between the ages of 3;0 (years;months) and 5;4 (CWS: mean age = 48.03 months; CWNS: mean age = 48.58 months). The CWS were matched by age ([+ or -] 4 months), gender, and race to the CWNS. All participants had speech, language, and hearing development within normal limits, with the obvious exception of stuttering for CWS. Children's temperamental characteristics were determined using the Behavioral Style Questionnaire (BSQ; S. C. McDevitt & W. B. Carey, 1978), which was completed by each child's parents. Results, based on parent responses to the BSQ, indicated that CWS are more apt, when compared to CWNS, to exhibit temperamental profiles consistent with hypervigilance (i.e., less distractibility), nonadaptability to change, and irregular biological functions. Findings suggest that some temperamental characteristics differentiate CWS From CWNS and could conceivably contribute to the exacerbation, as well as maintenance, of their stuttering. KEY WORDS: stuttering, temperament, children, development, Behavioral Style Questionnaire, Temperament refers to biologically based individual differences in behavioral characteristics of reactions that are present in infancy and are relatively stable across context and over time (Bates, 1989; Wachs, 1999). [...]

The question of whether people who stutter are generally more anxious than people who do not stutter has not yet been resolved. One major methodological barrier to determining whether differences exist has been the type of stuttering sample used. Studies investigating anxiety levels of those who stutter have mostly assessed people referred to stuttering therapy clinics, which is arguably a biased sample. To date, no studies have been published that have measured the anxiety levels of people who stutter in the community using random selection procedures. Such a sample is more likely to be representative of the population of people who stutter. The present study involved a random selection and telephone interview of people in 4,689 households. The telephone respondent was given a description of stuttering and asked if any person living in their household stuttered. If yes, a number of corroborative questions were asked, and permission was requested to tape the speech of the person believed to stutter over the telephone. A definite case of stuttering was based on (a) a positive detection of stuttering from the tape and (b) at least one of the corroborative questions supporting the diagnosis. A total of 87 people were identified as definite cases of stuttering across all ages, and 63 participants who were 15 years or older completed a trait anxiety questionnaire over the telephone. Mean trait anxiety levels were significantly higher than levels generally found in society, though differences were not large. Implications of these results are discussed. KEY WORDS: stuttering, anxiety, adult, children, The association between stuttering and anxiety has been robustly debated over the years, with early theorists arguing that anxiety plays a major causal role in the development of the disorder [...]

Research suggests that many people hold pervasive negative stereotypes towards persons who stutter and that to date, success in changing these attitudes has been limited. However, few studies have selected people who had not had direct contact with a person who stutters or employed a true randomized and stratified selection of people from the community to assess attitudes towards stuttering. To assess stereotypes, a randomized and stratified investigation was conducted by telephone interview to assess the type of stereotypes 502 people from households in the state of New South Wales, Australia have about stuttering. Consenting persons were given a brief introduction to the research and a description of stuttering. Then they were asked if they or any person living in their household stuttered or whether they knew or had ever met any one who stuttered. If answers were no, they were asked to participate. If they answered yes to either question they were thanked and not asked to participate. Analysis showed that a large number believe persons who stutter are shy, self-conscious, anxious people who lack confidence. In contrast, many also believe they would not be embarrassed talking to someone who stutters, that they have average or above average intelligence, and are capable of holding responsible work-related positions. While this research yields a mixture of negative and positive community stereotypes, a significant portion of society continue to show little knowledge of the causes of the disorder.

The Lidcombe Behavioral Data Language (LBDL; K. Bryant & A. Packman, 1999; A. Packman & M. Onslow, 1998; A. Packman, M. Onslow, & K. Bryant, 2000) is a recently developed taxonomy of stuttering. It fills a void in stuttering research because most current descriptive systems are taxonomies of disfluencies, not stuttering alone, and are not behaviorally based. This study is an investigation of intrajudge and interjudge agreement for the LBDL. Ten experienced speech-language pathologists and 10 undergraduate students received brief instruction in the LBDL and then applied it to 15 intervals of stuttered speech on 2 occasions. The speakers were children and adults. Intrajudge agreement was high for both groups but only experienced judges achieved satisfactory interjudge agreement. Results suggest that some stuttering behaviors may be easier to categorize than others. Possible applications of the LBDL to research and clinical practice in stuttering are discussed. KEY WORDS: stuttering, behavior, data, language, Are liable and valid data language ensures that those working within a discipline describe the behaviors of interest in the same way (Zuriff, 1985). Unfortunately, there is no such data [...]

Syntactic processing was explored in individuals who stutter (IWS). Grammaticality judgments and event-related brain potentials (ERPs) were obtained while participants read sentences, half containing verb-agreement violations. Grammaticality judgments for an offline verb-agreement task did not differ between IWS and normal speakers (NS). However, judgment accuracy of IWS for the online task was lower than that of NS, particularly for verb-agreement violations that occurred in longer and more syntactically complex sentences. Further, while NS exhibited a classic P600 ERP response to verb-agreement violations, the P600s of IWS were reduced in amplitude and distribution. The behavioral and ERP results are consistent with the hypothesis that underlying mechanisms mediating language processing, including those related to postlexical syntactic reanalysis, may operate atypically in IWS even in the absence of speech production demands. KEY WORDS: stuttering, language processing, event-related brain potentials, syntactic processing, neurophysiology, Stuttering a is disorder of fluency in which the forward flow of speech is disrupted by repetitions of words, sounds or syllables, prolongations, and silent blocks (Guitar, 1998). The multifactorial [...]

Considerable research has been directed at the outcomes of prolonged-speech (PS) treatment for the control of chronic stuttering, but little research to date has focused on the PS treatment process. This report examines a Stage 2 clinical trial of a reconceptualized PS treatment model known as the Camperdown Program. This program requires fewer clinician hours than traditional programs and has no formal transfer phase. Additionally, it incorporates the Following treatment process innovations, which replace treatment process components that are intuitively and empirically problematic: (a) PS is taught without incorporating target behaviors in clinician instruction, (b) participants learn to control stuttering without programmed instruction, and (c) the treatment process does not involve clinician identification of stuttering moments. Thirty participants were initially enrolled in the trial. Final outcome data are presented for the 16 participants who completed all trial requirements, including 12 months posttreatment data collection. These 16 participants showed minimal or no stuttering in everyday speaking situations for up to 12 months after entering the maintenance program, with speech rates in the normal range. Speech naturalness and social validation data were also favorable. Although self-report data generally confirmed the speech data, the results were not as positive. The present outcomes were achieved in a mean of 20 hours of clinic attendance per participant, which is much fewer than the hours required by treatment programs reported recently that run intensively over 2-3 weeks. The promise of this Stage 2 clinical trial has led the authors to initiate o Stage 3 randomized controlled trial of the Camperdown Program. KEY WORDS: stuttering treatment, adult, prolonged-speech model, Prolonged speech (PS) is specialized speech pattern that is used to establish stutter-free speech in a number of behavioral programs. Since Goldiamond's (1965) initial report on the procedure, treatments based [...]

Generalizability theory has been recommended as the most comprehensive method for assessing the reliability of observational data. It provides a framework for calculating the various sources of measurement error and allows further design of measurements for a particular purpose. This paper gives a practical illustration of how this method may be used in the analysis of observational data. We use the ratings of 15 unsophisticated raters using the 9-point speech naturalness scale of R. R. Martin, S. K. Haroldson, and K. A. Triden (1984) to evaluate the speech of adults before and after treatment for stuttering. We calculate various sources of measurement error and use these to estimate the minimum number of raters and ratings per rater for a reliable result. For posttreatment data, the average of three independent raters, and for pretreatment data, the average of five independent raters should give a result within one scale point of the hypothetical true score for the speaker in at least 80% of samples. The example illustrates the advantages of using this method of analysis. KEY WORDS: stuttering, generalizability theory, perceptual rating scales, speech naturalness, Recently it has become apparent that measures of clients' perceived speech naturalness are an essential addition to documented outcomes of treatments for adult stuttering (Ingham & Cordes, 1999; Ingham & [...]

This article reports the development of a tool for measuring how comfortable a person feels when communicating with someone who has undergone treatment for stuttering. The person rates the speaker on a 9-point Listener Comfort Scale (9 = extremely comfortable, 1 = extremely uncomfortable). In a preliminary investigation of the reliability and validity of the scale, 15 unsophisticated listeners rated video recordings of 10 adults before and after a prolonged-speech treatment for stuttering and of 10 matched controls. The results were compared with those of another 15 listeners who rated the same recordings with the widely used 9-point Speech Naturalness Scale (R. R. Martin, S. K. Haroldson, & K. A. Triden, 1984). Results showed that reliability of the Speech Naturalness Scale was superior to the Listener Comfort Scale, although users of both scales were able to distinguish between pretreatment speech, posttreatment speech, and the speech of controls. The results suggest that the Listener Comfort Scale captures information that is somewhat different than the information captured by the Speech Naturalness Scale. The authors concluded that the concept of listener comfort is a potentially useful additional way of investigating the social validity of behavioral treatments for stuttering. KEY WORDS: stuttering, social validity, listener comfort, outcome, speech naturalness, The best known and most effective methods for behavioral control of chronic stuttering are based on the use of the novel speech pattern known as prolonged speech (PS) and its [...]

This work investigated the hypothesis that neuromotor differences between individuals who stutter and individuals who do not stutter are not limited to the movements involved in speech production. Kinematic data were obtained from gender- and age-matched stuttering (n = 10) and nonstuttering (n = 10) adults during speech movements, orofacial nonspeech movements, and finger movements. All movements were performed in 4 conditions differing in sequence length and location of the target movement within the sequence. Results revealed statistically significant differences between the stuttering and nonstuttering individuals on several measures of lip and jaw closing (but not opening) movements during perceptually fluent speech. The magnitude of these differences varied across different levels of utterance length (larger differences during shorter utterances) and across different locations of the target movement within an utterance (larger differences close to the beginning). Results further revealed statistically significant differences between the stuttering and nonstuttering groups in finger flexion (but not extension) movement duration and peak velocity latency. Overall, findings suggest that differences between stuttering and nonstuttering individuals are not confined to the sensorimotor processes underlying speech production or even movements of the orofacial system in general. Rather, it appears that the groups show generalized differences in the duration of certain goal-directed movements across unrelated motor systems. KEY WORDS: stuttering, speech motor control, nonspeech motor control, kinematic analysis, Considerable evidence has accumulated in support of the view that individuals who stutter, as a group, differ from individuals who do not stutter in at least some of the neuromotor [...]

Fourteen individuals who stutter and 14 individuals who do not stutter were presented with 10 bursts of white noise to assess the magnitude of their eyeblink responses as a measure of temperament. Both the magnitude of the eyeblink response to the initial noise burst and the mean of the 10 responses were significantly greater for the stuttering group. The Taylor-Johnson Temperament Analysis (R. M. Taylor & L. P. Morrison, 1996) did not distinguish between the two groups, but informal follow-up statistics indicated that the Nervous subscale showed a significant group difference. Scores on this subscale were also significantly positively correlated with the magnitude of the startle response. A discriminant analysis demonstrated that although both the startle response and the nervous trait differentiated the two groups, the startle response measures were more powerful in making this differentiation. KEY WORDS: stuttering, temperament, startle, It is often said that stuttering emerges as a result of an interaction between constitutional and environmental factors (e.g., Bloodstein, 1995; Van Riper, 1982). A number of writers have further [...]

The present study examined language and fluency characteristics of single-utterance (SU) and multiple-utterance (MU) conversational turns produced by 15 preschoolers who stutter and 15 age- and sex-matched preschoolers who do not stutter. Participants conversed with a parent in a play setting. Each interaction was videotaped and the participants' resultant utterances were transcribed and analyzed. Results indicated that the children's utterances from MU-turns typically served assertive functions and were significantly longer and more linguistically complex than their utterances from SU-turns. Neither group showed a significant difference in disfluency rate for length-matched utterances from MU- and SU-turns. Similarly, there were no significant between-group differences in speaking-turn length or frequency of MU-turns. Although present findings do not support the hypothesis that MU-turns directly affect children's fluency, they do suggest that MU-turns are demanding for youngsters because they evoke relatively long and complex utterances. A such, conversational turn length seems to be an important variable for clinicians to consider when assessing and treating children who stutter. KEY WORDS: stuttering, fluency disorders, normal language development, pragmatics, discourse analysis, During the past 25 years, numerous studies have been conducted to examine the effects of linguistic factors on the fluency of children who stutter (see Bloodstein, 1995; Ratner, 1995, for [...]

This study investigated stuttering frequency as a function of grammatical word type (i.e., content and function). Ten adults who stutter participated. Participants recited aloud a list of 126 words consisting of an equal number of content and function words, which were presented individually and visually via a laptop computer. Each word belonged to a single grammatical category. Further, words were matched for initial sound and approximate number of syllables. The results indicated that adults who stutter exhibited significantly greater stuttering frequency on content words when presented in isolation (p = 0.018). It was conjectured that the responsible factor contributing to differences in stuttering frequency in adults who stutter resides in word frequency disparities between the two classes of words categories. That is, because the function words are limited in number and are used frequently, repeated use on the part of adults who stutter may lead to a generalized adaptation effect for function words and hence reduced stuttering frequency (as compared with content words). KEY WORDS: stuttering, content words, function words, open/closed class words, word frequency, Grammatically, words are classified as either content or function words. Nouns, verbs, adjectives, and adverbs are considered content words; whereas prepositions, conjunctions, pronouns, auxiliary verbs, inflections, and interjections are considered [...]

The purpose of this study was to assess anticipatory coarticulation and second formant (F2) transition rate (FTR) of speech production in young children who stutter (CWS) and who do not stutter (CWNS). Fourteen CWS and 14 age- and gender-matched CWNS in three age groups (3-, 4-, and 5-year-olds) participated in a picture-naming task that elicited single-word utterances. The initial consonant-vowel (CV) syllables of these utterances, comprising either bilabial [b m] or alveolar [d n s z] consonants and a number of vowels [i I e [epsilon] ae u o [??] [??]], were used for acoustic analysis. To assess coarticulation and speech movement velocity, the F2 onset frequency and F2 vowel target frequency (for coarticulation) and FTR (for speech movement velocity) were computed for each CV syllable and for each participant. Based on these measures, locus equation statistics of slope, y-intercept, and standard error of estimate as well as the FTR were analyzed. Findings revealed a significant main effect for place of articulation and a significantly larger difference in FTR between the two places of articulation for CWNS than for O/VS. Findings suggest that the organization of the FTR production for place of articulation may not be as contrastive or refined in CWS as in CWNS, a subtle difficulty in the speed of speech-language production, which may contribute to the disruption of their speech fluency. KEY WORDS: stuttering, coarticulalion, children, speech acoustics, transition rate, Recent theories of stuttering suggested that people who stutter have an impaired or slower-than-normal phonological encoding ability (Perkins, Kent, & Curlee, 1991; Postma & Kolk, 1993; Wingate, 1988). Although it [...]

The purpose of this investigation was to quantitatively and qualitatively characterize speech disfluencies exhibited by 3- and 4-year-old children who do (CWS, N = 36) and do not (CWNS, N = 36) stutter. Five measures of speech disfluency (e.g., percentage of total, other, and stuttering-like disfluencies, mean number of repetition units, and weighted SLD measure) were used in attempts to differentiate CWS from CWNS. Similar measures of stuttering (e.g., percentage of stuttering-like disfluencies consisting of disrhythmic phonations) were used to characterize speech disfluencies in 3- and 4-year-old CWS in relation to time since stuttering onset (TSO). It was hypothesized that such measures of speech disfluency should significantly differ between CWS and CWNS, as well as 3- versus 4-year-old CWS in relation to TSO. Results indicated that 4 out of the 5 dependent measures significantly differed between CWS and CWNS, and within the CWS group there was a significant relationship between TSO and the percentage of stuttering-like disfluencies when the effects of chronological age were partialled out of the regression analyses. Furthermore, 4-year-old CWS exhibited a moderate correlation between TSO and the percentage of stuttering-like disfluencies consisting of disrhythmic phonations, whereas 3-year-old CWS exhibited no such relationship between these two variables. Findings were taken to suggest that certain measures of speech disfluency appreciably differentiate CWS from CWNS and that 4-year-old CWS exhibit changes in nonreiterative forms of stuttering as a function of time since stuttering onset. KEY WORDS: stuttering, preschool, time since onset, stuttering-like disfluencies, weighted SLD measure, In recent years, researchers have increased their attempts to characterize speech and nonspeech behavior(s) associated with stuttering exhibited by young children (e.g., Ambrose & Yairi, 1999; Conture & Kelly, 1991; [...]

Byline: D. S. Matoyan (1) Abstract: The effect of inverse masking on the skin of the left and right hands and of bimanual reverse masking during coordinated work of both hands in stutterers was studied to detect the changes in cerebral asymmetry related to stuttering. The study showed that (1) asymmetry of tactile perception is absent in stutterers in the conditions of masking it is supposed that when stuttering begins in early childhood, the formation of the hemispheric specialization in performing both sensory (all modalities) and speech functions is interrupted (2) stuttering right-handers demonstrate a strongly 'levotropic nature' of the interhemispheric interactions under conditions of bimanual masking, which testifies to a more considerable 'retardation' of the perception of a test stimulus in the stutterers' left hemisphere under the influence of the masking stimulus in the right hemisphere than in right-handers with normal speech. It is assumed on this basis that stuttering begins because of the combination of symmetry and asymmetry in the interhemispheric relations. There is a hypothetical model that supposes that the phenomenon of stuttering is caused by two fundamental factors, namely, bilateral symmetry (existence of two identical speech centers in the right and left hemispheres) and a specific 'levotropic' asymmetry of the interhemispheric relations, i.e., a more manifest influence of the right hemisphere on the left hemisphere in stutterers. This conditions the emergence of two identical speech impulses that appear with long intervals between them, which cause a dissonance in the functioning of the speech-forming apparatus. Author Affiliation: (1) Abovyan Armenian State Pedagogical Institute, Yerevan, Armenia Article History: Registration Date: 16/10/2004

Byline: E. S. Dmitrieva (1), V. Ya. Gel'man (1) Abstract: The reaction time for the recognition of different emotions in speech against a background of noise in stutterers and normally speaking children between the ages of 7 to 17 years was studied. The specific differences between these two types of subjects in processing the emotional speech component were more markedly pronounced in terms of the reaction time than the effectiveness of recognition. An increase in the noise level decreases the effectiveness of recognition and increases the reaction time however, the stutterers do not show a statistically significant lengthening of the reaction time. With increasing age, the recognition time of the emotion type in both groups of subjects is shortened, although sex-related differences may be observed: only in stuttering girls is the difference in the recognition time between the junior and senior groups great enough and comparable to that of normally speaking girls. The stuttering children (SC) were found to have significantly shorter recognition times of the emotion types than their normally speaking counterparts. In this connection, the hypothesis about the specific features of processing the acoustic signal in the sensory memory of SC was advanced. These results suggest that the specific features of the processes occurring in the memory subsystems of stutterers may be one of the causes of stuttering, along with the differences in interhemispheric relations found in previous works. Author Affiliation: (1) Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, pr. Toreza 44, St. Petersburg, 194223, Russia Article History: Registration Date: 16/10/2004