The transition to increased automaticity during finger sequence learning in adult males who stutter

The present study compared the automaticity levels of persons who stutter (PWS) and persons who do not stutter (PNS) on a practiced finger sequencing task under dual task conditions. Automaticity was defined as the amount of attention required for task performance. Twelve PWS and 12 control subjects practiced finger tapping sequences under single and then dual task conditions. Control subjects performed the sequencing task significantly faster and less variably under single versus dual task conditions while PWS' performance was consistently slow and variable (comparable to the dual task performance of control subjects) under both conditions. Control subjects were significantly more accurate on a colour recognition distracter task than PWS under dual task conditions. These results suggested that control subjects transitioned to quick, accurate and increasingly automatic performance on the sequencing task after practice, while PWS did not. Because most stuttering treatment programs for adults include practice and automatization of new motor speech skills, findings of this finger sequencing study and future studies of speech sequence learning may have important implications for how to maximize stuttering treatment effectiveness. Educational objectives: As a result of this activity, the participant will be able to: (1) Define automaticity and explain the importance of dual task paradigms to investigate automaticity; (2) Relate the proposed relationship between motor learning and automaticity as stated by the authors; (3) Summarize the reviewed literature concerning the performance of PWS on dual tasks; and (4) Explain why the ability to transition to automaticity during motor learning may have important clinical implications for stuttering treatment effectiveness.     

Speech and nonspeech sequence skill learning in adults who stutter

Two studies compared the speech and nonspeech sequence skill learning of nine persons who stutter (PWS) and nine matched fluent speakers (PNS). Sequence skill learning was defined as a continuing process of stable improvement in speed and/or accuracy of sequencing performance over practice and was measured by comparing PWS's and PNS's performance curves of accuracy, reaction time, and sequence duration, as well as retention and transfer. In experiment one, participants completed a 30-trial finger tapping sequence and in experiment two, a 30-trial read-aloud sequence of nonsense syllables. Significant between-group differences were found in the speed of sequencing performance after practice, and on retention and transfer tests. These results partially supported the inference that PWS demonstrated differences in early stages of sequence skill learning compared to PNS. EDUCATIONAL OBJECTIVES: As a result of this activity the participant will be able to: (1) define skill learning and the important indicators of skill learning; (2) summarize the reviewed literature concerning the performance of PWS on speech and nonspeech sequencing tasks over practice; and (3) explain the implication of reaction time differences over practice between PWS and PNS.     

Investigating speech motor practice and learning in people who stutter

In this exploratory study, we investigated whether or not people who stutter (PWS) show motor practice and learning changes similar to those of people who do not stutter (PNS). To this end, five PWS and five PNS repeated a set of non-words at two different rates (normal and fast) across three test sessions (T1, T2 on the same day and T3 on a separate day, at least 1 week apart). The results indicated that PWS and PNS may resemble each other on a number of performance variables (such as movement amplitude and duration), but they differ in terms of practice and learning on variables that relate to movement stability and strength of coordination patterns. These findings are interpreted in support of recent claims about speech motor skill limitations in PWS.

Educational objectives: The reader will be able to: (1) define oral articulatory changes associated with motor practice and learning and their measurement; (2) summarize findings from previous studies examining motor practice and learning in PWS; and (3) discuss hypotheses that could account for the present findings that suggest PWS and PNS differ in their speech motor learning abilities.     

Verbal Implicit Sequence Learning in Persons Who Stutter and Persons With Parkinson's Disease

The authors investigated the integrity of implicit learning systems in 14 persons with Parkinson's disease (PPD), 14 persons who stutter (PWS), and 14 control participants. In a 120-min session participants completed a verbal serial reaction time task, naming aloud 4 syllables in response to 4 visual stimuli. Unbeknownst to participants, the syllables formed a repeating 8-item sequence. PWS and PPD demonstrated slower reaction times for early but not late learning trials relative to controls reflecting delays but not deficiencies in general learning. PPD also demonstrated less accuracy in general learning relative to controls. All groups demonstrated similar limited explicit sequence knowledge. Both PWS and PPD demonstrated significantly less implicit sequence learning relative to controls, suggesting that stuttering may be associated with compromised functional integrity of the cortico-striato-thalamo-cortical loop.     

Retention of Implicit Sequence Learning in Persons Who Stutter and Persons With Parkinson's Disease

ABSTRACT. The authors investigated the retention of implicit sequence learning in 14 persons with Parkinson's disease (PPD), 14 persons who stutter (PWS), and 14 control participants. Participants completed a nonsense syllable serial reaction time task in a 120-min session. Participants named aloud 4 syllables in response to 4 visual stimuli. The syllables formed a repeating 8-item sequence not made known to participants. After 1 week, participants completed a 60-min retention session that included an explicit learning questionnaire and a sequence generation task. PPD showed retention of general learning equivalent to controls but PWS's reaction times were significantly slower on early trials of the retention test relative to other groups. Controls showed implicit learning during the initial session that was retained on the retention test. In contrast, PPD and PWS did not demonstrate significant implicit learning until the retention test suggesting intact, but delayed, learning and retention of implicit sequencing skills. All groups demonstrated similar limited explicit sequence knowledge. Performance differences between PWS and PPD relative to controls during the initial session and on early retention trials indicated possible dysfunction of the cortico-striato-thalamo-cortical loop. The etiological implications for stuttering, and clinical implications for both populations, of this dysfunction are discussed.     

Stuttering: a dynamic motor control disorder

The purpose of this review is to determine what neural mechanisms may be dysfunctional in stuttering. Three sources of evidence are reviewed. First, studies of dynamic inter-relationships among brain regions during normal speech and in persons who stutter (PWS) suggest that the timing of neural activity in different regions may be abnormal in PWS. Second, the brain lesions associated with acquired stuttering are reviewed. These indicate that in a high percentage of cases, the primary speech and language regions are not affected but lesions involve other structures, such as the basal ganglia, which may modulate the primary speech and language regions. Third, to characterize the motor control disorder in stuttering, similarities and differences from focal dystonias such as spasmodic dysphonia (SD) and Tourette’s syndrome (TS) are reviewed. This review indicates that the central control abnormalities in stuttering are not due to disturbance in one particular brain region but rather a system dysfunction that interferes with rapid and dynamic speech processing for production.

Educational objectives: The reader will be able to describe: (1) the similarities and differences between stuttering and other speech motor control disorders, (2) which brain lesions are most likely to produce acquired stuttering in adults, and (3) what type of brain abnormality most likely underlies stuttering.     

图-词干扰范式下汉语口吃者的语义编码

采用图-词干扰范式, 通过2个实验考察了汉语口吃者的语义编码。实验1发现, 在基本水平命名中,口吃者与非口吃者均表现出语义干扰效应, 语义相关干扰词的命名时间显著长于语义无关干扰词的命名时间, 口吃者在语义相关干扰条件下所受到的干扰比非口吃者大; 在类别水平命名中, 口吃者与非口吃者的表现类似, 都表现出语义促进效应, 语义相关干扰词的命名时间显著短于语义无关干扰词的命名时间, 语义相关干扰词的命名错误率也显著低于语义无关干扰词的命名错误率。实验2发现, 在基本水平命名中, 当SOA为-200 ms、-100 ms和0 ms时, 语义相关干扰条件下的反应时显著长于在语义无关干扰条件下的反应时, 当SOA为-100 ms和0 ms时, 口吃者的语义干扰效应比非口吃者更加明显。整个研究表明, 口吃者的语义编码出现了延缓, 口吃者比非口吃者需要更多的时间来排除语义干扰词的干扰。研究结果在一定程度上支持了关于口吃的多因素模型。     

汉语口吃者在不出声言语中的语音编码

口吃者与非口吃者在不出声言语中语音编码的差异是口吃者语音加工异常的有力证据。通过三个实验,分别考察了口吃者与非口吃者监控汉语拼音中声母、韵母及声调的差异。结果表明,口吃者对声母的监控与非口吃者相比没有显著的差异,但在监控韵母及声调时,口吃者的反应显著慢于非口吃者。研究结果支持了关于口吃的“内在修正假说”,对研究汉语的语音编码有启发,对于口吃的诊断和治疗也有重要的启示     

Providing explicit information disrupts implicit motor learning after basal ganglia stroke

Despite their purported neuroanatomic and functional isolation, empirical evidence suggests that sometimes conscious explicit processes can influence implicit motor skill learning. Our goal was to determine if the provision of explicit information affected implicit motor-sequence learning after damage to the basal ganglia. Individuals with stroke affecting the basal ganglia (BG) and healthy controls (HC) practiced a continuous implicit motor-sequencing task; half were provided with explicit information (EI) and half were not (No-EI). The focus of brain damage for both BG groups was in the putamen. All of the EI participants were at least explicitly aware of the repeating sequence. Across three days of practice, explicit information had a differential effect on the groups. Explicit information disrupted acquisition performance in participants with basal ganglia stroke but not healthy controls. By retention (day 4), a dissociation was apparent--explicit information hindered implicit learning in participants with basal ganglia lesions but aided healthy controls. It appears that after basal ganglia stroke explicit information is less helpful in the development of the motor plan than is discovering a motor solution using the implicit system alone. This may be due to the increased demand placed on working memory by explicit information. Thus, basal ganglia integrity may be a crucial factor in determining the efficacy of explicit information for implicit motor-sequence learning.     

Analysis of five cases with neurogenic stuttering following brain injury in the basal ganglia

This study examined stuttering patterns in five patients with basal ganglia injury. None of the patients had a history of developmental stuttering. Four patients were right-handed; one patient was ambidextrous. Stuttering tests administered to patients assessed sentence repetition, reading aloud, explanations of a comic strip, and conversation. Accessory behaviors such as facial grimaces, associated movements of the limbs, and avoidance behaviors were observed. The results of this study differ from those of previous studies of neurogenic stuttering in several respects: (1) blocks were frequently observed. (2) Adaptation was observed. (3) Almost all stuttering occurred at the initiation of words. (4) Across patients, stuttering frequency did not vary in a consistent manner with speaking task. New speech characteristics for neurogenic stuttering without aphasia following injury to the basal ganglia are described.Educational objectives: After reading this text, the reader will be able to: (1) provide characteristics of neurogenic stuttering after the basal ganglia in patients without aphasia; (2) discuss the difference of the features and characteristics of stuttering between previously reported patients and present patients.     

The nature and treatment of stuttering as revealed by fMRI A within- and between-group comparison

This article reviews some of our recent functional magnetic resonance imaging (fMRI) studies of stuttering. Using event-related fMRI experiments, we investigated brain activation during speech production. Results of three studies comparing persons who stutter (PWS) and persons who do not stutter (PWNS) are outlined. Their findings point to a region in the right frontal operculum (RFO) that was consistently implicated in stuttering. During overt reading and before fluency shaping therapy, PWS showed higher and more distributed neuronal activation than PWNS. Immediately after therapy differential activations were even more distributed and left sided. They extended to frontal, temporal, and parietal regions, anterior cingulate, insula, and putamen. These over-activations were slightly reduced and again more right sided two years after therapy. Left frontal deactivations remained stable over two years of observation, and therefore possibly indicate a dysfunction. After therapy, we noted higher activations in persons who stutter moderately than in those who stutter severely. These activations might reflect patterns of compensation. We discuss why these findings suggest that fluency-inducing techniques might synchronize a disturbed signal transmission between auditory, speech motor planning, and motor areas.

Educational objectives: The reader will learn about and be able to: (1) identify regions of brain activations and deactivations specific for PWS; (2) describe brain activation changes induced by fluency shaping therapy; and (3) discuss the correlation between stuttering severity and brain activation.     

Effects of stuttering severity and therapy involvement on attitudes towards people who stutter

The purpose of this study was to explore whether stuttering severity or therapy involvement had an effect on the attitudes that individuals who do not stutter reported towards people who stutter (PWS). Two hundred and sixty (260) university students participated in this study. Direct survey procedures consisting of a 25-item semantic differential scale were utilized. Comparisons of the effects of stuttering severity, level of therapy involvement, and the interaction of these variables were completed. Results suggested that both stuttering severity and therapy involvement had significant effects on participants' attitudes towards PWS. Findings of this study support past research studies that has found that individuals who stutter mildly are perceived more positively than those who are severe. Similarly, the data supported past research that has found that PWS that attend therapy are perceived more positively than those who do not attend therapy. Surprisingly, the interaction of these variables was not significant. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) explain the possible effects of listeners' attitudes toward stuttering on the lives of PWS; (2) discuss how different factors might alter listeners' attitudes towards stuttering; (3) delineate how stuttering severity and involvement in therapy might impact listeners' attitudes towards PWS.     

Frequency of stuttering during challenging and supportive virtual reality job interviews

This paper seeks to demonstrate the possibility of manipulating the frequency of stuttering using virtual reality environments (VREs). If stuttering manifests itself in VREs similarly to the way it manifests itself in real world interactions, then VREs can provide a controlled, safe, and confidential method for treatment practice and generalization. Though many researchers and clinicians recognize the need for generalization activities in the treatment of stuttering, achieving generalization in a clinical setting poses challenges to client confidentiality, safety, and the efficient use of a professionals’ time. Virtual reality (VR) technology may allow professionals the opportunity to enhance and assess treatment generalization while protecting the safety and confidentiality of their clients. In this study, we developed a VR job interview environment which allowed experimental control over communication style and gender of interviewers. In this first trial, persons who stutter (PWS) experienced both challenging and supportive VR job interview conditions. The percentage of stuttered syllables was calculated for both interviews for each participant. Self-reported ratings of communication apprehension and confidence were also obtained, and were not significantly correlated with stuttering severity. Results indicated that interviewer communication style affected the amount of stuttering produced by participants, with more stuttering observed during challenging virtual interviews. Additionally, the amount of stuttering observed during the VR job interviews was significantly, positively correlated with the amount of stuttering observed during an interview with the investigator prior to VR exposure. Participants’ subjective reports of the VR experience indicate reactions similar to those they report experiencing in the real world. Possible implications for the use of VR in the assessment and treatment of stuttering are discussed.

Educational objectives: After reading this article, the reader will be able to—(1) list some of the challenges to treatment generalization; (2) describe how virtual reality technology can assist in alleviating some of these challenges; (3) describe how the frequency of stuttering varies across two different virtual environments.     

Phoneme monitoring in silent naming and perception in adults who stutter

The present study investigated phonological encoding skills in persons who stutter (PWS). Participants were 10 PWS (M = 31.8 years, S.D. = 5.9) matched for age, gender, and handedness with 12 persons who do not stutter (PNS) (M = 24.3 years, S.D. = 4.3). The groups were compared in a phoneme monitoring task performed during silent picture naming. The phonological complexity of the target items in the task was varied such that participants monitored either compound words or noun phrases. Performance in this task was compared to phoneme monitoring performed on aurally presented target words to investigate whether any differences observed in silent naming were also evident in perception. Analysis of the response time data, in milliseconds, indicated that PWS were significantly slower as compared to PNS in phoneme monitoring during silent naming; group differences were not obtained in the perception task. The groups were also comparable in the response time to phoneme monitoring within compound words and noun phrases in both silent naming and perception. The findings suggested that PWS were slower in the encoding of segmental, phonological units during silent naming. Furthermore, absence of such differences in perception ruled out a general monitoring deficit in PWS. Findings are interpreted within the context of the psycholinguistic theories of stuttering that postulate phonological encoding and/or monitoring as a causal variable in stuttering.

Educational objectives: As a result of this activity, the participant should: (1) describe relevant literature on phonological encoding skills in children and adults who stutter, (2) identify paradigms that can be used to investigate phonological processing in PWS, and (3) discuss the role of phonological encoding in speech production.     

The impact of threat and cognitive stress on speech motor control in people who stutter

PurposeIn the present study, an Emotional Stroop and Classical Stroop task were used to separate the effect of threat content and cognitive stress from the phonetic features of words on motor preparation and execution processes.MethodA group of 10 people who stutter (PWS) and 10 matched people who do not stutter (PNS) repeated colour names for threat content words and neutral words, as well as for traditional Stroop stimuli. Data collection included speech acoustics and movement data from upper lip and lower lip using 3D EMA.ResultsPWS in both tasks were slower to respond and showed smaller upper lip movement ranges than PNS. For the Emotional Stroop task only, PWS were found to show larger inter-lip phase differences compared to PNS. General threat words were executed with faster lower lip movements (larger range and shorter duration) in both groups, but only PWS showed a change in upper lip movements. For stutter specific threat words, both groups showed a more variable lip coordination pattern, but only PWS showed a delay in reaction time compared to neutral words. Individual stuttered words showed no effects. Both groups showed a classical Stroop interference effect in reaction time but no changes in motor variables.ConclusionThis study shows differential motor responses in PWS compared to controls for specific threat words. Cognitive stress was not found to affect stuttering individuals differently than controls or that its impact spreads to motor execution processes.Educational objectives: After reading this article, the reader will be able to: (1) discuss the importance of understanding how threat content influences speech motor control in people who stutter and non-stuttering speakers; (2) discuss the need to use tasks like the Emotional Stroop and Regular Stroop to separate phonetic (word-bound) based impact on fluency from other factors in people who stutter; and (3) describe the role of anxiety and cognitive stress on speech motor processes.     

Severity of dysfluency correlates with basal ganglia activity in persistent developmental stuttering

Previous studies suggest that anatomical anomalies [Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering. Neurology, 57, 207-215; Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., & Heilman, K. M. (2003). Atypical cerebral laterality in adults with persistent developmental stuttering. Neurology, 61, 1378-1385; Foundas, A. L., Bollich, A. M., Feldman, J., Corey, D. M., Hurley, M., & Lemen, L. C. et al., (2004). Aberrant auditory processing and atypical planum temporale in developmental stuttering. Neurology, 63, 1640-1646; Jancke, L., Hanggi, J., & Steinmetz, H. (2004). Morphological brain differences between adult stutterers and non-stutterers. BMC Neurology, 4, 23], in particular a reduction of the white matter anisotropy underlying the left sensorimotor cortex [Sommer, M., Koch, M. A., Paulus, W., Weiller, C., & Buchel, C. (2002). Disconnection of speech-relevant brain areas in persistent developmental stuttering. Lancet, 360, 380-383] could be at the origin of persistent developmental stuttering (PDS). Because neural connections between the motor cortex and basal ganglia are implicated in speech motor functions, PDS could also be associated with a dysfunction in basal ganglia activity [Alm, P. (2004). Stuttering and the basal ganglia circuits: a critical review of possible relations. Journal of Communication Disorders, 37, 325-369]. This fMRI study reports a correlation between severity of stuttering and activity in the basal ganglia and shows that this activity is modified by fluency shaping therapy through long-term therapy effects that reflect speech production improvement. A model of dysfunction in stuttering and possible repair modes is proposed that accommodates the data presented here and observations previously made by us and by others.     

Health and human services for persons who stutter and education of logopedists in East-European countries

The International Association of Logopedics and Phoniatrics (IALP) assessed the therapy status of fluency disorders, service opportunities, and education of logopedists (speech-language pathologists) with a mail survey in Eastern Europe. Information was collected on the following aspects: incidence, prevalence, availability of information, non-therapeutic support for persons who stutter (PWS), providers of diagnostics and therapy, cooperating professionals, therapy approaches, forms, goals, financing, early detection and prevention, training of professionals, specialization in stuttering therapy, needs for improving the situation of PWS, and problems which hinder better care. Stuttering therapy for children is available in many countries and is frequently provided by the educational system. Therapy for adults is provided best by the health services but is not satisfactorily available everywhere. Modern therapeutic approaches coexist with obsolete ones. Lack of resources, awareness, entitlement, and assessment of therapy effectiveness are pervasive problems.

Educational objectives: Readers will be able to describe and evaluate: (1) the therapy status of fluency disorders and service opportunities in various East-European countries; (2) the training of logopedists (speech-language pathologists); (3) specialization in stuttering therapy; and (4) the organizational services for PWS within the health and human service systems.     

Phonological encoding in the silent speech of persons who stutter

The purpose of the present study was to investigate the role of phonological encoding in the silent speech of persons who stutter (PWS) and persons who do not stutter (PNS). Participants were 10 PWS (M=30.4 years, S.D.=7.8), matched in age, gender, and handedness with 11 PNS (M=30.1 years, S.D.=7.8). Each participant performed five tasks: a familiarization task, an overt picture naming task, a task of self-monitoring target phonemes during concurrent silent picture naming, a task of monitoring target pure tones in aurally presented tonal sequences, and a simple motor task requiring finger button clicks in response to an auditory tone. Results indicated that PWS were significantly slower in phoneme monitoring compared to PNS. No significant between-group differences were present for response speed during the auditory monitoring, picture naming or simple motor tasks, nor did the two groups differ for percent errors in any of the experimental tasks. The findings were interpreted to suggest a specific deficiency at the level of phonological monitoring, rather than a general monitoring, reaction time or auditory monitoring deficit in PWS. Educational objectives: As a result of this activity, the participant should: (1) identify and assess the literature on phonological encoding skills in PWS, (2) enumerate and evaluate some major psycholinguistic theories of stuttering, and (3) describe the mechanism by which defective phonological encoding can disrupt fluent speech production.     

Self-help conferences for people who stutter: a qualitative investigation

Self-help activities for people who stutter (PWS) have been gaining in popularity; however, there is a scarcity of evidence to support their utility in stuttering management. The purpose of this investigation was to understand the lived experience of individuals who attended a self-help conference(s) for PWS from the perspective of a PWS to learn its potential utility in stuttering management. The investigator used Interpretive Phenomenological Analysis (IPA) to systematically collect authentic data of this social phenomenon. Twelve participants were recruited from a self-help conference and the self-help community of PWS. Semi-structured interviews were conducted 4–18 months after each participant's last conference. Interviews were transcribed and analyzed. Themes were explained in investigator narratives and illustrated through participants’ quotes. Interpreted themes of the experience of having attended a self-help conference(s) for PWS included: socializing opportunities with other PWS, affiliation, redefining oneself and post-conference disclosures. A conclusion of the study was that the experience of having attended a self-help conference(s) for PWS helped to minimize negative impact that stuttering can have on daily functioning. It appears that self-help conferences were perceived as a safer or “stutter-friendly” environment and promoted social interaction, relationship building, and community building through planned and unplanned activities. Another conclusion was that the experience of having attended self-help conferences for PWS helped participants to communicate more easily. Reported increases in social activity and an “openness” about stuttering, suggest self-help conferences’ utility in stuttering management. These findings are supported by other studies about successful stuttering management and self-help activities for PWS. They have helped attendees who stutter to communicate more easily and suggest a reduction in the negative impact that stuttering has on their lives.Educational objectives: The reader will be able to: (1) describe recurring themes associated with the lived experience having attended a self-help conference(s) for people who stutter (PWS) from the perspective of a group of adults who stutter, and (2) describe the potential benefits of attending self-help conferences for PWS in order to make appropriate evidence-based referrals to self-help conferences for PWS.