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     

口吃儿童言语产生中的抑制控制：来自出声Go/Nogo任务的证据

抑制控制在言语产生中起重要作用,其功能异常可能是造成口吃的原因之一。前人研究发现成年口吃者存在与抑制控制相关的脑区(右侧额下回)的过度激活,但在口吃儿童中没有。此外,关于口吃儿童抑制控制的行为研究只运用了按键任务,结果也存在很大争议。故本研究运用出声Go/Nogo任务检验口吃儿童在言语产生中的反应抑制能力。结果发现,口吃组与对照组在击中和虚报的反应时、漏报率和虚报率上均未表现出组间差异,而且口吃组的这些指标与口吃程度也没有显著相关。在排除速度与准确率的权衡后,上述结果支持口吃儿童在言语产生中对发音运动的反应抑制并不存在普遍缺陷,在一定程度上支持了成年口吃者右侧额下回过度激活的补偿解释。     

口吃者加工汉语歧义短语的神经过程

韵律边界是口语韵律特征的有机组成部分, 在语言理解中发挥着重要作用。口吃作为一种言语节律性障碍, 主要表现为音节经常性的重复、拖长或停顿等。本研究采用ERP, 考察口吃者完成词汇判断和结构判断两种任务时, 加工歧义短语(动宾/偏正歧义结构)内部韵律边界的认知过程。结果发现口吃者和言语流畅者在加工汉语歧义短语过程中, 所诱发的反映韵律切分的脑电成分CPS (closure positive shift)不存在显著差异。在0~300 ms, 不论中线还是两侧, 口吃者和言语流畅者加工两类短语时, 动宾短语韵律边界诱发正效应的头皮分布范围小于偏正短语。在300~600 ms, 中线上, 口吃和言语流畅者在完成两种任务时, 两类短语的韵律边界均稳定诱发了正效应; 在两侧, 结构判断任务中两类短语的韵律边界都诱发了正效应, 但词汇判断任务中只有偏正短语稳定诱发该效应。综上, 口吃者和言语流畅者一样对口语韵律边界敏感, 并且他们加工歧义短语内部韵律边界时, 诱发的脑电效应受到实验任务和短语结构类型的影响。     

口吃者的言语计划缺陷——来自词长效应的证据

口吃者与非口吃者在词长效应上的差异是口吃语音编码缺陷的一个重要的支持证据。本研究在综述词长效应研究的基础上,对这种解释提出了三点置疑,即词频、句法复杂性和发音长度也可能是造成词长效应差异的主要原因,并通过三个实验进行了验证。实验一和实验三在口吃者和非口吃者之间都得到了稳定的词长效应差异,并且排除了词频和发音长度对于这种差异的影响;实验二在控制词长的条件下,发现口吃者对于句法复杂性是敏感的。因此,本研究的结果支持口吃在言语产出中的语音编码和句法编码中都存在缺陷。同时,本研究对于口吃治疗也提供了有价值的参考建议     

刷新功能对汉语口吃者语音编码的影响

该研究采用双任务实验范式比较了口吃者和非口吃者在色点位置刷新任务的同时重复双声词和叠韵词的反应时和口吃频率。结果表明,口吃者和非口吃者加工叠韵词比加工双声词均需要更多的刷新功能。研究结果支持了口吃的"内在修正假说",对口吃的诊断和治疗有重要的启示。     

转换功能对汉语口吃者语音编码的影响

采用双任务范式比较了16名口吃者和16名非口吃者在数字转换任务的同时重复双声词和叠韵词的时间和口吃频率,考察转换功能对于汉语口吃者语音编码的影响。结果表明,转换功能影响汉语口吃者的语音编码：口吃者和非口吃者加工叠韵词比加工双声词需要更多的转换功能。研究结果支持口吃的“内在修正假说”,对口吃的诊断和治疗有重要启示。     

口吃的脑成像研究

口吃(Stuttering)是一种常见的言语流畅性障碍。关于口吃的原因一直有很多争论。近十年来,随着脑成像技术的发展,越来越多的研究者倾向认为口吃是一种中枢神经系统的功能障碍,并尝试用PETf、MRI和MEG等多种方法考察口吃者的脑功能变化。本文围绕几个重要的理论,回顾了近10多年来口吃脑成像研究的进展,提出了各理论相融合的途径,分析了这些研究的价值和问题,讨论了进一步的研究方向。     

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。     

发展性口吃的脑机制

口吃是一种常见的言语障碍,对此曾提出过大脑半球言语功能偏侧化异常假设。近期,发展性口吃的神经成像研究在支持这一经典假设的同时,还发现负责言语监控的颞叶系统和负责言语运动控制的额叶系统与皮层下脑结构存在功能失调,这可能损害言语产生时的精确时间控制。据此,研究者开始用神经网络的观点来解释发展性口吃产生的脑机制,认为患者可能存在由多个言语产生相关脑区构成的“双通路”网络的功能障碍     

口吃的语言大师

他从小就是个患有严重口吃的孩子。10岁那年，他参加学校的演讲比赛，话刚出口就遭到满堂哄笑，他第一次深刻体味到了口吃者的困窘。放学的路上，淘气的同学意扰未尽，仍然学着他口吃的腔调轮番表演，他备感屈辱，哭着奔回家，责问母亲：为什么你要生下一个口吃的孩子？母亲陪着他一起掉眼泪。     

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.     

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.     

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.     

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 influence of workplace discrimination and vigilance on job satisfaction with people who stutter

Purpose The purpose of the present study is to examine the association between workplace discrimination, vigilance, and job satisfaction in people who stutter and compare this with people who do not stutter. Method Seventy-two people who stutter (PWS) and 92 people who do not stutter (PWNS) participated in an online survey. Participants completed a survey assessing 6 different areas: (a) background information, (b) job satisfaction, (c) everyday discrimination, and (d) heightened vigilance. Mediation analyses were conducted to evaluate the relationship between the independent variables and dependent variable. Results There was a relationship between being a PWS and job satisfaction, discrimination, and vigilance. PWS were found to experience higher discrimination as well as be more vigilant. Discrimination and vigilance were found to mediate the relationship between stuttering and job satisfaction. Conclusion Results of this study indicate that the participants who stutter differ from PWNS in their job satisfaction, discrimination, and vigilance. Clinicians can prepare PWS with self-advocacy strategies, legal knowledge of what their rights are as an employee who identifies as a person who stutters with a disability, a legal understanding of workplace discrimination, and counseling on the impact of vigilance on workplace experiences.     

Neurophysiologic markers of primary motor cortex for laryngeal muscles and premotor cortex in caudal opercular part of inferior frontal gyrus investigated in motor speech disorder: a navigated transcranial magnetic stimulation (TMS) study

Transcranial magnetic stimulation studies have so far reported the results of mapping the primary motor cortex (M1) for hand and tongue muscles in stuttering disorder. This study was designed to evaluate the feasibility of repetitive navigated transcranial magnetic stimulation (rTMS) for locating the M1 for laryngeal muscle and premotor cortical area in the caudal opercular part of inferior frontal gyrus, corresponding to Broca’s area in stuttering subjects by applying new methodology for mapping these motor speech areas. Sixteen stuttering and eleven control subjects underwent rTMS motor speech mapping using modified patterned rTMS. The subjects performed visual object naming task during rTMS applied to the (a) left M1 for laryngeal muscles for recording corticobulbar motor-evoked potentials (CoMEP) from cricothyroid muscle and (b) left premotor cortical area in the caudal opercular part of inferior frontal gyrus while recording long latency responses (LLR) from cricothyroid muscle. The latency of CoMEP in control subjects was 11.75 ± 2.07 ms and CoMEP amplitude was 294.47 ± 208.87 µV, and in stuttering subjects CoMEP latency was 12.13 ± 0.75 ms and 504.64 ± 487.93 µV CoMEP amplitude. The latency of LLR in control subjects was 52.8 ± 8.6 ms and 54.95 ± 4.86 in stuttering subjects. No significant differences were found in CoMEP latency, CoMEP amplitude, and LLR latency between stuttering and control-fluent speakers. These results indicate there are probably no differences in stuttering compared to controls in functional anatomy of the pathway used for transmission of information from premotor cortex to the M1 cortices for laryngeal muscle representation and from there via corticobulbar tract to laryngeal muscles.     

Anxiety and speaking in people who stutter: An investigation using the emotional Stroop task

People with anxiety disorders show an attentional bias towards threat or negative emotion words. This exploratory study examined whether people who stutter (PWS), who can be anxious when speaking, show similar bias and whether reactions to threat words also influence speech motor planning and execution. Comparisons were made between 31 PWS and 31 fluent controls in a modified emotional Stroop task where, depending on a visual cue, participants named the colour of threat and neutral words at either a normal or fast articulation rate. In a manual version of the same task participants pressed the corresponding colour button with either a long or short duration. PWS but not controls were slower to respond to threat words than neutral words, however, this emotionality effect was only evident for verbal responding. Emotionality did not interact with speech rate, but the size of the emotionality effect among PWS did correlate with frequency of stuttering. Results suggest PWS show an attentional bias to threat words similar to that found in people with anxiety disorder. In addition, this bias appears to be contingent on engaging the speech production system as a response modality. No evidence was found to indicate that emotional reactivity during the Stroop task constrains or destabilises, perhaps via arousal mechanisms, speech motor adjustment or execution for PWS.Educational objectives: The reader will be able to: (1) explain the importance of cognitive aspects of anxiety, such as attentional biases, in the possible cause and/or maintenance of anxiety in people who stutter, (2) explain how the emotional Stroop task can be used as a measure of attentional bias to threat information, and (3) evaluate the findings with respect to the relationship between attentional bias to threat information and speech production in people who stutter.     

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.