Genetic studies of stuttering in a founder population

Genome-wide linkage and association analyses were conducted to identify genetic determinants of stuttering in a founder population in which 48 individuals affected with stuttering are connected in a single 232-person genealogy. A novel approach was devised to account for all necessary relationships to enable multipoint linkage analysis. Regions with nominal evidence for linkage were found on chromosomes 3 (P=0.013, 208.8 centiMorgans (cM)), 13 (P=0.012, 52.6 cM), and 15 (P=0.02, 100 cM). Regions with nominal evidence for association with stuttering that overlapped with a linkage signal are located on chromosomes 3 (P=0.0047, 195 cM), 9 (P=0.0067, 46.5 cM), and 13 (P=0.0055, 52.6 cM). We also conducted the first meta-analysis for stuttering using results from linkage studies in the Hutterites and The Illinois International Genetics of Stuttering Project and identified regions with nominal evidence for linkage on chromosomes 2 (P=0.013, 180-195 cM) and 5 (P=0.0051, 105-120 cM; P=0.015, 120-135 cM). None of the linkage signals detected in the Hutterite sample alone, or in the meta-analysis, meet genome-wide criteria for significance, although some of the stronger signals overlap linkage mapping signals previously reported for other speech and language disorders. EDUCATIONAL OBJECTIVES: After reading this article, the reader will be able to: (1) summarize information about the background of common disorders and methodology of genetic studies; (2) evaluate the role of genetics in stuttering; (3) discuss the value of using founder populations in genetic studies; (4) articulate the importance of combining several studies in a meta-analysis; (5) discuss the overlap of genetic signals identified in stuttering with other speech and language disorders.     

Voluntary stuttering suppresses true stuttering: a window on the speech perception-production link

In accord with a proposed innate link between speech perception and production (e.g., motor theory), this study provides compelling evidence for the inhibition of stuttering events in people who stutter prior to the initiation of the intended speech act, via both the perception and the production of speech gestures. Stuttering frequency during reading was reduced in 10 adults who stutter by approximately 40% in three of four experimental conditions: (1) following passive audiovisual presentation (i.e., viewing and hearing) of another person producing pseudostuttering (stutter-like syllabic repetitions) and following active shadowing of both (2) pseudostuttered and (3) fluent speech. Stuttering was not inhibited during reading following passive audiovisual presentation of fluent speech. Syllabic repetitions can inhibit stuttering both when produced and when perceived, and we suggest that these elementary stuttering forms may serve as compensatory speech gestures for releasing involuntary stuttering blocks by engaging mirror neuronal systems that are predisposed for fluent gestural imitation.     

Listener perceptions of stuttering and stuttering modification techniques

PurposeThe purpose of this study was to analyse naïve listener perceptions of speech containing unmodified stuttering, use of the pull-out technique, and use of preparatory-sets.MethodParticipants (N = 62) were randomly assigned to listen to one audio sample (unmodified stuttered speech, speech with pull-outs, or speech with preparatory-sets) and completed a survey assessing perceptions of the speaker’s speech and personality and the listener’s comfort level and willingness to social interact with the speaker.ResultsSurvey results revealed low perceptual ratings in all experimental conditions. Unmodified stuttered speech received significantly more positive ratings than the stuttering modification conditions in all measurements except for speech naturalness. Listeners reported being less willing to socially interact with those who use preparatory-sets than unmodified stuttered speech.ConclusionThe use of stuttering modification techniques did not improve listeners’ perceptions or willingness to interact with persons who stutter. Clinicians and those who stutter should be aware that the use of speech techniques will not decrease negative social interactions or stereotypes.     

Subtyping stuttering I: a review

A reliable and practical subtype system of stuttering should enhance all related scientific work concerned with this disorder. Although a fair number of classification systems have been offered, to date, none has received wide recognition or has been routinely applied in research or clinical spheres. Whereas progress has been made in understanding and treating the disorder, for the most part stuttering continues to be viewed and addressed as a unitary problem. The objectives of the current article are to (a) highlight the motivation for identifying sub-types of stuttering, (b) outline the issues involved in researching subtypes, and (c) address the question of whether or not subtyping is plausible for this disorder. Toward these ends, a broad-based review of past concepts regarding subtypes of stuttering and stutterers is presented according to seven categories that reflect the various authors' conceptual or experimental approaches. Selected studies for each category are also presented to illustrate the research problems and challenges. It is concluded that islands of progress can be identified in subtype research, particularly in studies of children. It is recommended that future studies include multiple factors or domains in the data collection process, especially with young children during the formative years of the disorder, when substantial overlap in the development of several speech/language domains occurs. EDUCATIONAL OBJECTIVES: (a) Readers will be able to describe the theory and research concerning the numerous attempts to subtype stuttering, particularly during the past 50 years; (b) Readers will be able to explain the general issues that need to be resolved in order to identify subtypes as well as current and future research strategies aimed at achieving these goals.     

Cluttering and stuttering exhibited in a young professional

S 18, a young adult professional, was self-referred for stuttering. Assessment indicated deficits consistent with both stuttering and cluttering, including prolongations, syllable repetitions, secondary escape behaviors, rapid speech rate, and poor expressive language. The client had no awareness of cluttering characteristics. Therapy goals included improved breath control, slowed rate, easier onset of articulation, and increased awareness of speech. Progress toward therapeutic goals was consistent. However, his motivation decreased as therapy progressed. He was discharged from direct treatment after 13 months, at which time he could employ therapeutic techniques to improve his fluency and intelligibility when speech was disordered.     

An analysis of a token economy in stuttering therapy

A stuttering therapy program in which adult stutterers were hospitalized and treated in small groups (n = 4) under token economy conditions is described. The Token System reinforced reductions and penalized increases in stuttering during conversation. The therapy program was divided into three stages. Initially, subjects were treated by the token system, which was then integrated with a delayed auditory feedback schedule designed to instate and shape a prolonged speech pattern into normal fluent speech. Finally, subjects passed through a speech situation hierarchy while under token control conditions. Experiments conducted in the first two stages of treatment are described. The first-stage experiments examined the design of the token system; the second-stage experiment assessed the effect of a contingent punishment schedule integrated with the delayed auditory feedback procedure in order to shape rate of speaking as well as fluency.     

Horn stuttering

This is a case report on an adult male stutterer who also exhibited stuttering-like behavior while playing the French horn. The effects of speech fluency targets on the playing and the physiological and psychological correlates between the stutter in speech and the “stuttering-like” behaviors when playing an instrument are discussed. Etiological implications are considered.     

The chronic perseverative stuttering syndrome; Incurable stuttering

After recounting the story of Todd to illustrate the significance of the issue, the chronic perseverative stuttering (CPS) syndrome is defined and its characteristics identified. After a discussion of treatment goals for the CPS syndrome client, the significance of its identification in the client's teenage years and its relevance to support groups for stutterers, the paper concludes with a call for acknowledging the reality of the CPS syndrome and for establishing realistic therapy goals in view of its existence.     

Acquired stuttering

Working from a case of degeneration of the nervous system accompanied by stutterlike repetitions, this article raises the question whether patients should be said to have acquired stuttering when they evidence only one of the typical symptoms of the syndrome. On the other hand, it is shown that when acquired stuttering is polysymptomatic, it can hardly be distinguished from developmental stuttering on the basis of the patient's verbal behavior. This may have important medicolegal implications. When acquired stuttering occurs in the context of aphasia, both affections appear to be relatively independent of each other. Specifically, there seems to be no causal relationship between them.     

Flute stuttering

A case is reported of a stutterer who exhibited stuttering-like behavior while playing the flute in a highly competitive school orchestra. Theoretical implications are discussed.     

fMRI of developmental stuttering: a pilot study

The purpose of this investigation was to explore the feasibility of fMRI in the study of developmental stuttering. Speech contrasts (loud versus silent reading) and language contrasts (reading of semantically meaningful text versus nonsense words) of six developmental stutterers and six nonstutterers were compared using a commercial 1 Tesla MR-Scanner (Siemens Expert). Results indicate that mapping cortical function in persons who stutter is indeed feasible, even with a 1TMR-system. Compared to normals the stutterers seemed to employ different and particularly less differentiated auditory and motor feedback strategies in speech. They apparently rely on auditory processing and on cerebellar contribution as much during silent reading as during reading aloud. Moreover, they showed a greater involvement of the right hemisphere in language processing, activating not only the typical language areas on the left but also and with equal magnitude the right side homologues of these areas. In spite of the promising results, at present several practical problems such as possible movement artifacts and possible masking through scanner noise still hamper a more straightforward use of fMRI in the study of developmental stuttering.     

Acquired stuttering as a forerunner of motor-neuron disease

A case of acquired stuttering that included repetitions, blocks, prolongations, fillers, and, later on, also synkinesias is reported. This stutter turned out to be the forerunner of a motor-neuron disease.     

Assessment of stuttering in a familiar versus an unfamiliar language

The present study investigated how well individuals knowledgeable about stuttering are able to make disfluency judgments in clients who speak another language than their own. Fourteen native speakers of Brazilian Portuguese identified and judged stuttering in Dutch speakers and in Portuguese speakers. Fourteen native speakers of Dutch identified and judged stuttering in Brazilian Portuguese speakers and in Dutch speakers. It was found that judges can make similar level of judgment in a native and a foreign language, and that native and foreign judges can make similar level of judgment irrespective of native/foreign differences. It was also found, however, that the Dutch judges performed significantly better in identifying native stutterers than foreign stutterers. And for the identification of nonstutterers, both panels performed better in their native language than in the foreign language, and in their native language they both performed better than the other panel. Both the Brazilian Portuguese and the Dutch speaking panel were generally also less confident, and found identification of stuttering more difficult in the foreign language than in the native language. In addition, when asked for the characteristics that helped them identify stutterers, they provided more detail in the native language than in the foreign language. Also a number of differences were found between the two panels which may be due to differences in training or cultural background. The implications of the findings for clinical practice and for future research in this area are discussed. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe how language influences the identification of a speech disorder such as stuttering, and (2) list, and (3) define behaviors that help to identify stuttering in a foreign language.