Edward G. Conture, Ph.D. - US grants

DESCRIPTION: (Adapted From The Applicant's Abstract) The primary objective of this project is to study the co-occurrence of stuttering and phonological disorders in young children. It is hypothesized that children who stutter but evidence normal phonological development: (1) stutter because of a disparity between speech rate performance and speech rate ability; and (2) evidence sound/syllable repetitions containing appropriate CV or VC transitions. In contrast, children who stutter and have co-existing phonological disorders: (1) stutter because of difficulties controlling, correctly producing and stabilizing speech; and (2) evidence sound/syllable repetitions with missing or inappropriate CV or VC transitions. Subjects will be 120 children, 3-7 years of age, in four age-and sex-matched groups of stutterers and nonstutterers, with and without co-existing phonological disorders. Acoustic and perceptual data from recordings of the children conversing with their mothers and naming pictures will be used to answer the following questions: (1) do the four groups differ in speaking and/or diadochokinetic rate? (2) do the four groups differ in frequency of missing or inappropriate transitions during sound/syllable repetitions and/or ability to initiate phonation of sound prolongations? (3) do the two groups of stutterers differ in frequency of sound/syllable and/or monosyllabic word repetitions or in percentage of stutterings that are sound prolongations? and (4) are there statistical relationships between speech and diadochokinetic rates, frequency/nature of speech disfluencies, percentage of sounds produced correctly and the frequency and nature of the phonological processes evidenced among the four groups? Findings are intended to: (1) clarify relationships between disordered phonology and stuttering in children; (2) pinpoint factors contributing to stuttering of children with normal and disordered phonology; and (3) identify perceptual and acoustic indexes of children's "atypical" and "typical" disfluencies as well as promising areas of clinical management.

DESCRIPTION: (Adapted from the investigator s abstract): The percentage (30-40%) of young children who stutter who also exhibit disordered phonology is far greater than the percentage (2-6%) of disordered phonology in the general population. Unfortunately, no completely satisfactory theory currently exists to account for the separate occurrence of either stuttering or disordered phonology, much less their common co-occurrence. It would appear, however, that their co-occurrence offers a unique window into the variables that may cause, exacerbate or maintain both disorders. One theory recently advanced for explaining stuttering is based on the model of normal fluent speech production developed by Levelt. This covert-repair hypothesis (CRH) suggests that the phonological encoding of children who stutter is impaired. This impairment is most problematic when these children make their phonological selections too rapidly. Due to these overly-rapid phonological selections, children who stutter are more apt to make selection errors, thus causing them to more frequently self-repair (self-correct), with resulting stutterings. The project seeks to assess differences between: (1) self-repairs in words with systematic (rule-governed) versus nonsystematic ("slips of the tongue") speech errors, (2) stutterings in words with versus without systematic speech errors, (3) syllable complexity in words with versus without non-systematic speech errors, (4) the ratio of self-repairs to nonsystematic speech errors in children who stutter versus children who do not stutter, and (5) nonsystematic speech errors and speech disfluencies associated with phonologically facilitated versus non-facilitated picture naming responses. Findings from these studies will have important theoretical implications for onset and development of stuttering, place stuttering within the broader context of normal and abnormal speech and language development, and inform diagnostic and treatment approaches for children who stutter.

[unreadable] DESCRIPTION (provided by applicant): While motoric aspects of stuttering such as speech motor control have received considerable attention, developing lines of evidence suggest that linguistic variables such as syntax, semantics and phonology may also contribute to stuttering. At present, no completely satisfactory theory exists for the separate occurrence of childhood stuttering and difficulties with linguistic processing (e.g., lexical storage and/or retrieval), much less their common co-occurrence. Developing such theory, one might assume that disruptions in linguistic planning of speech-language production contribute to stuttering and that such disruptions are most likely temporal in nature given that stuttering is, by definition, a disruption in the rhythm or fluency of speech. Based on these assumptions, it could be speculated that the linguistic planning for speech-language production of people who stutter is slow, perhaps dyssynchronous, a possibility that may contribute to the overt hesitations, repetitions, and stoppages in speech that comprise the sine qua non of stuttering. Thus, the specific aims of the project are to assess differences in speech reaction time between children who do and do not stutter during conditions where speed of syntactic, semantic and phonological activation has been experimentally manipulated by priming procedures during picture-naming or picture description tasks. The possibility that subgroups exist among these children, based on their performance on these tasks as well as standardized tests, will also be explored through appropriate multivariate statistical procedures. Furthermore, the influence of these priming procedures will be studied for children with high-normal versus low-normal syntactic, semantic and phonologic abilities. Finally, the relationship between aspects of stuttering (e.g., most common disfluency type) and changes in speech reaction time during these experimental tasks will also be studied. Findings will have important theoretical implications regarding linguistic contributions to stuttering in children and help ground stuttering within the broader context of (ab)normal speech and language development as well as inform diagnostic and treatment protocols for childhood stuttering.

The current applicants propose that the emotional reactions of children who stutter and their attempts to regulate these reactions contribute to the exacerbation and maintenance of their stuttering. The applicants' model of childhood stuttering suggests that subtle and not-so-subtle linguistic, motoric and communicative difficulties (e.g., Anderson & Conture, 2004; Pellowski & Conture, in press) may initiate stuttering in ayoung child. Subsequently, the child reacts to instances of stuttering by becoming more aroused and reactive, and these reactions may or may not be modulated by the child's regulatory or coping skills. Our model predicts that levels of emotional reactivity and regulation/coping of children who stutter will differ from those of their normally fluent peers. We also predict that changes in emotional reactivity and regulation will beassociated with changes in stuttering. We will examine the following hypotheses for 3- to 5-year-old children who do and do not stutter: (1) Are there naturally-occurring differences between children who do and do not stutter with regard to emotional reactivity and regulation as rated by parents and trained examiners (Proposed Study 1)? (2) Are there differences between children who do and do not stutter with regardto emotional reactivity and regulation during structured laboratory situations (Proposed Study 2)? (3) Does emotional reactivity differ between children who do and do not stutter when presented with arousing environmental stimulation and is reactivity associated with stuttering and other disfluencies (Proposed Study 3)? (4) Do experimental variations in emotion regulation influence stuttering for children who stutter (Proposed Study 4)? These studies are an initial attempt to relate emotional development and behavior to childhood stuttering when children areconfronted with change or challenge. These interdisciplinary investigations - involving collaboration between developmental psychology and speech-language pathology- should help determine whether some children who stutter are less able to regulate distress or modulate their reactivity and clarify the link between emotional reactivity, regulation, and childhood stuttering. Results will ground the study of childhood stuttering within the broader context of childhood emotional development, and focus future research on issues that inform diagnostic and treatment protocols for childhood stuttering.

DESCRIPTION (provided by applicant): Stuttering has a lifetime incidence (i.e., percentage of adults who ever stuttered) of nearly 5% and significantly impacts the academic, emotional, social, and vocational achievements, development and potential of individuals who stutter (see Bloodstein &Bernstein Ratner, 2008). However, seventy-eighty percent of those affected discontinue (e.g., Yairi &Ambrose, 1999) without significant formal treatment (i.e., "unassisted" recovery). For the remaining children (i.e., approximately 1% of children who continue to stutter after 6 years of age), the negative impact of stuttering on their lives and daily activities can be significant. There is a strong need, therefore, to determine variables that may initiate/cause, exacerbate or perpetuate stuttering to develop more efficient, effective empirically-based approaches to diagnosis and treatment. Further, as Yairi (1993) noted, "Because advanced stuttering is markedly different from the incipient form...attempts to infer its [stuttering's] etiology and nature or to prescribe treatment for children who stutter based on models derived from adult stutterers are indefensible" (Conture, 1991;Yairi, 1990;p.198). Thus, it is imperative to examine variables in the period during which stuttering typically begins. To address this imperative, we propose a longitudinal study of preschool-age children who stutter, with emphasis on how emotion and speech-language processes contribute to developmental stuttering. Building on Monroe and Simons'(1991) etiological notion of diathesis-stress interactions, the applicants'conceptual model proposes that dual diatheses (i.e., emotional and/or speech-language vulnerabilities) are activated by environmental stressors (e.g., changes, differences, novelty in structure and/or changes in need to spontaneously generate speech-language) to cause stuttering. This model assumes that a finite number of combinations of emotional and/or speech-language variables contribute to meaningful differences between children who do and do not stutter, as well as between children who recover and those who persist. The proposed project builds on our preliminary findings and theoretical model, longitudinally, to relate emotional and speech-language to developmental stuttering, using multiple methods (i.e., observational, standardized testing, parent-report, and psychophysiology) that assess our major constructs of emotion and speech-language. This interdisciplinary investigation - involving collaboration between developmental psychology and speech-language pathology - should help determine whether children at the onset of stuttering differ from their normally fluent peers on emotion and speech-language variables and whether these differences, over time, predict which children will and will not recover. Findings from this longitudinal investigation will help ground the study of stuttering within the broader context of emotional and speech- language development and help focus future research on issues that inform diagnostic and treatment protocols for childhood stuttering. PUBLIC HEALTH RELEVANCE: Stuttering has a lifetime incidence (i.e., percentage of adults who stuttered at some point) of nearly 5% and significantly impacts the academic, emotional, social, and vocational achievements, development and potential of individuals who stutter (see Bloodstein and Bernstein Ratner, 2008;Conture, 1996;Yairi, 1997). For the remaining children (i.e., the approximately 1% of children who continue to stutter after 6 years of age), the negative impact of stuttering on their lives and daily activities can be significant. Thus, there is a strong need to determine those variables that may initiate/cause, exacerbate or perpetuate stuttering - as this project will attempt to do - in order to eventually develop more efficient, effective empirically-based approaches to the diagnosis and treatment of stuttering.