Speech and nonspeech: What are we talking about?

Is the Articulatory Trajectory of Changing Syllables Important for Achieving Higher Syllable Rates Compared to Repeated Syllables?

PURPOSE

The production of speech-like sequences composed of varying syllables has been reported to achieve higher syllable rates than the production of repeated syllables (commonly designed as sequential motion rate [SMR] and alternating motion rate [AMR] tasks, respectively). The faster rate for SMR relative to AMR sequences is explained by different interpretative hypotheses, which remain empirically unexplored. In the present study, we aimed to investigate whether the high syllable rates of SMR sequences are due to the specific sequences used in most studies that involve front-to-back articulatory movements.

METHOD

Syllable rates of SMR sequences composed of different articulatory trajectories (i.e., labial-alveolar-velar [/pateko/], alveolar-velar-labial [/tekopa/], and velar-labial-alveolar [/kopate/]) were compared with those of the AMR sequences /papapa/, /tetete/, and /kokoko/ in 20 participants.

RESULTS

The results show higher syllable rates for each of the three SMR sequences as compared to AMR, suggesting that the trajectory of the articulatory movements in the sequential sequences is not the key to achieving higher syllable rates.

CONCLUSION

The syllable rate advantage for SMR over AMR sequences is not explained by the articulatory trajectories included in the former task, indicating that the front-to-back movements generally included in SMR sequences (i.e., /pataka/) are not decisive in achieving a higher syllable rate.

Individual Differences in Accent Imitation

All talkers show some flexibility in their speech, and the ability to imitate an unfamiliar accent is a skill that shows vast individual differences. Yet the source of these individual differences, in particular whether they originate from perceptual, motor, or social/personality factors, is not yet clear. In the current study, we ask how individual differences in these factors predict individual differences in deliberate accent imitation. Participants imitated three accents, and attempts were rated for accuracy. A set of measures tracking individual differences in perceptual, motor, cognitive, personality, and demographic factors were also acquired. Imitation ability was related to differences in musical perception, vocal articulation, and the personality characteristic of "openness to experience," and was affected by attitudes towards the imitated talkers. Taken together, results suggest that deliberate accent imitation skill is modulated not only by core perceptual and motor skills, but also by personality and affinity to the talker, suggesting that some aspects of deliberate imitation are a function of domain-general constraints on perceptual-motor systems, while others may be modulated by social context.

A Fine-Grained Temporal Analysis of Multimodal Oral Diadochokinetic Performance to Assess Speech Impairment in Amyotrophic Lateral Sclerosis

PURPOSE

This study used a semiautomated fine-grained temporal analysis to extract features of temporal oral diadochokinetic (DDK) performance across multiple modalities and tasks, from neurologically healthy and impaired individuals secondary to amyotrophic lateral sclerosis (ALS). The aims were to (a) delineate temporal oral DDK deficits relating to the neuromotor pathology of ALS and (b) identify the optimal task-feature combinations to detect speech impairment in ALS.

METHOD

Mandibular myoelectric, kinematic, and acoustic data were acquired from 13 individuals with ALS and 10 healthy controls producing three alternating motion rate tasks and one sequential motion rate task. Twenty-seven features were extracted from the multimodal data, characterizing three temporal constructs: duration/rate, variability, and coordination. The disease impacts on these features were assessed across tasks, and the task eliciting the greatest disease-related change was identified for each feature. Such "optimal" task-feature combinations were fed into logistic regression to differentiate individuals with ALS from healthy controls.

RESULTS

Temporal deficits in ALS were characterized by (a) increased duration and variability and reduced coordination of jaw muscle activities, (b) increased duration and variability and altered temporal symmetry of jaw velocity profile, (c) increased muscle-burst-to-peak-velocity duration, and (d) increased motion-to-voice onset duration. These temporal features were differentially affected across tasks. The optimal task-feature combinations, which were further clustered into three composite factors reflecting temporal variability, coarser-grained duration, and finer-grained duration, differentiated ALS from controls with an F1 score of 0.86 (precision = 1.00, recall = 0.75).

CONCLUSIONS

Temporal oral DDK deficits are likely attributed to a hierarchy of interrelated neurophysiological and biomechanical factors associated with the neuromotor pathology of ALS. These deficits, as assessed crossmodally, provide previously unavailable insights into the multifaceted timing impairment of oromotor performance in ALS. The optimal task-feature combinations targeting these deficits show promise as quantitative markers for (early) detection of speech impairment in ALS.

Shared and Separate Neuromuscular Underpinnings of Swallowing and Motor Speech Development in the School-Age Years

PURPOSE

Despite co-occurrence of swallowing and speech disorders in childhood, there is limited research on shared and separate neuromuscular underpinnings of these functions. The purpose of this study was to (a) compare neuromuscular control of swallowing and speech between younger and older children and (b) determine similarities and differences in neuromuscular control of swallowing and speech.

METHOD

Twenty-six typically developing children (thirteen 7- to 8-year-olds and thirteen 11- to 12-year-olds) completed this cross-sectional study. Neuromuscular control was evaluated using surface electromyography of submental muscles and superior and inferior orbicularis oris muscles during parallel tasks of swallowing and speech. Outcome measures included normalized mean amplitude, burst duration, time to peak amplitude, and bilateral synchrony, which were examined using mixed-effects models.

RESULTS

For normalized mean amplitude, burst duration, and time to peak amplitude, there were significant two- and three-way interactions between muscle group, task, and age group, indicating that older and younger children demonstrated different muscle activation patterns, and these patterns varied by muscle and task. No differences were noted between groups for bilateral synchrony. For parallel tasks, children demonstrated different magnitudes of normalized mean amplitude and time to peak amplitude of speech and swallowing. However, they demonstrated a similar pattern: increases in magnitude as task complexity increased.

CONCLUSIONS

Children continue to demonstrate refinement of their neuromuscular control of swallowing and speech between 7-8 and 11-12 years of age, and there are both shared and separate elements of neuromuscular control between these two vital functions. To improve generalizability of findings, future research should include longitudinal analysis of swallowing and speech development, as well as measures of central neurophysiology.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23796258.

Oral diadochokinetic production in children with typical speech development and speech-sound disorders

BACKGROUND

AIMS: To investigate the developmental trajectory of the rate and perceptual assessment of oral diadochokinesis (DDK) in typically developing children compared with adults. Also to examine the characteristics of DDK productions in children with speech sound disorders (SSD) and the relationship between DDK production and percentage of consonants correct (PCC).

METHODS & PROCEDURES

Participants were 316 typically developing children and 90 children with SSD from 3 to 9 years old, as well as 20 adults with normal speech. The mono-, bi- and trisyllabic nonsense strings containing Korean tense consonants and the vowel [a] were used for DDK tasks. The number of iterations per s was measured as the DDK rate for each stimulus. The perceptual assessment of DDK productions was also performed for regularity, accuracy and rate.

OUTCOMES & RESULTS

The DDK rates increased throughout childhood, but the oldest children, 9-year-olds in the current study, did not achieve adult-like rates for all mono- and trisyllabic strings. Children with SSD also did not show significant differences from typically developing children when the DDK productions were analysed using only accurate tokens. The PCC of children with SSD showed higher correlations with regularity, accuracy and rate of perceptual ratings than the timed DDK rate.

CONCLUSIONS & IMPLICATIONS

This study highlighted the fact that the comprehensive evaluation of DDK productions may provide even more useful information about children's oral motor skills.

WHAT THIS PAPER ADDS

What is already known on the subject Rates of DDK reflect the motor skills of the articulatory systems independently of phonological skills; therefore, the tasks are widely used in the diagnostic evaluations of speech disorders in both children and adult populations. However, a substantial number of studies have questioned the validity and usefulness of DDK rates for evaluating speech abilities. Also, the literature suggested that the measure of DDK rate alone does not provide a clear and useful indication of children's oral motor skills. DDK tasks should be analysed in terms of accuracy and consistency as well as rate. What this paper adds to the existing knowledge The literature reporting normative DDK performance has mainly been based on English speakers. As different consonants have different temporal characteristics, the linguistic and segmental features of DDK tasks can impact the DDK rate. This study established a norm for DDK rate for Korean-speaking children and investigated the developmental trajectory of DDK performance in typically developing children compared with adults. This study suggested that the comprehensive evaluation of DDK productions may provide even more useful information about children's oral motor skills by examining the characteristics of DDK productions in children with SSD. What are the potential or actual clinical implications of this work? This study provided normative data of young Korean-speaking children aged 3-9 years. Normative data in children under 5 years of age are valuable given that the majority of children referred for speech difficulty assessments are between 3 and 5 years of age, but only a few studies have provided the normative data in young children. This study showed that many children could not complete DDK tasks correctly and provided additional support for the notion that other aspects of DDK performance, including accuracy and regularity, may yield more useful diagnostic indications than timed DDK rates alone.

Diadochokinesis Performance and Its Link to Cognitive Control: Alternating Versus Non-Alternating Diadochokinesis

PURPOSE

In a previous publication, we observed that maximum speech performance in a nonclinical sample of young adult speakers producing alternating diadochokinesis (DDK) sequences (e.g., rapidly repeating "pataka") was associated with cognitive control: Those with better cognitive switching abilities (i.e., switching flexibly between tasks or mental sets) showed higher DDK accuracy. To follow up on these results, we investigated whether this previously observed association is specific to the rapid production of alternating sequences or also holds for non-alternating sequences (e.g., "tatata").

METHOD

For the same sample of 78 young adults as in our previous study, we additionally analyzed their accuracy and rate performance on non-alternating sequences to investigate whether executive control abilities (i.e., indices of speakers' updating, inhibition, and switching abilities) were more strongly associated with production of alternating, as compared with non-alternating, sequences.

RESULTS

Of the three executive control abilities, only switching predicted both DDK accuracy and rate. The association between cognitive switching (and updating ability) and DDK accuracy was only observed for alternating sequences. The DDK rate model included a simple effect of cognitive switching, such that those with better switching ability showed slower diadochokinetic rates across the board. Thus, those with better cognitive ability showed more accurate (alternating) diadochokinetic production and slower maximum rates for both alternating and non-alternating sequences.

CONCLUSION

These combined results suggest that those with better executive control have better control over their maximum speech performance and show that the link between cognitive control and maximum speech performance also holds for non-alternating sequences.

Oromotor Nonverbal Performance and Speech Motor Control: Theory and Review of Empirical Evidence

This position paper offers a perspective on the long-standing debate concerning the role of oromotor, nonverbal gestures in understanding typical and disordered speech motor control secondary to neurological disease. Oromotor nonverbal tasks are employed routinely in clinical and research settings, but a coherent rationale for their use is needed. The use of oromotor nonverbal performance to diagnose disease or dysarthria type, versus specific aspects of speech production deficits that contribute to loss of speech intelligibility, is argued to be an important part of the debate. Framing these issues are two models of speech motor control, the Integrative Model (IM) and Task-Dependent Model (TDM), which yield contrasting predictions of the relationship between oromotor nonverbal performance and speech motor control. Theoretical and empirical literature on task specificity in limb, hand, and eye motor control is reviewed to demonstrate its relevance to speech motor control. The IM rejects task specificity in speech motor control, whereas the TDM is defined by it. The theoretical claim of the IM proponents that the TDM requires a special, dedicated neural mechanism for speech production is rejected. Based on theoretical and empirical information, the utility of oromotor nonverbal tasks as a window into speech motor control is questionable.

Inhibitory Synaptic Influences on Developmental Motor Disorders

During development, GABA and glycine play major trophic and synaptic roles in the establishment of the neuromotor system. In this review, we summarise the formation, function and maturation of GABAergic and glycinergic synapses within neuromotor circuits during development. We take special care to discuss the differences in limb and respiratory neuromotor control. We then investigate the influences that GABAergic and glycinergic neurotransmission has on two major developmental neuromotor disorders: Rett syndrome and spastic cerebral palsy. We present these two syndromes in order to contrast the approaches to disease mechanism and therapy. While both conditions have motor dysfunctions at their core, one condition Rett syndrome, despite having myriad symptoms, has scientists focused on the breathing abnormalities and their alleviation-to great clinical advances. By contrast, cerebral palsy remains a scientific quagmire or poor definitions, no widely adopted model and a lack of therapeutic focus. We conclude that the sheer abundance of diversity of inhibitory neurotransmitter targets should provide hope for intractable conditions, particularly those that exhibit broad spectra of dysfunction-such as spastic cerebral palsy and Rett syndrome.

Speech and Nonspeech Parameters in the Clinical Assessment of Dysarthria: A Dimensional Analysis

Nonspeech (or paraspeech) parameters are widely used in clinical assessment of speech impairment in persons with dysarthria (PWD). Virtually every standard clinical instrument used in dysarthria diagnostics includes nonspeech parameters, often in considerable numbers. While theoretical considerations have challenged the validity of these measures as markers of speech impairment, only a few studies have directly examined their relationship to speech parameters on a broader scale. This study was designed to investigate how nonspeech parameters commonly used in clinical dysarthria assessment relate to speech characteristics of dysarthria in individuals with movement disorders. Maximum syllable repetition rates, accuracies, and rates of isolated and repetitive nonspeech oral-facial movements and maximum phonation times were compared with auditory-perceptual and acoustic speech parameters. Overall, 23 diagnostic parameters were assessed in a sample of 130 patients with movement disorders of six etiologies. Each variable was standardized for its distribution and for age and sex effects in 130 neurotypical speakers. Exploratory Graph Analysis (EGA) and Confirmatory Factor Analysis (CFA) were used to examine the factor structure underlying the diagnostic parameters. In the first analysis, we tested the hypothesis that nonspeech parameters combine with speech parameters within diagnostic dimensions representing domain-general motor control principles. In a second analysis, we tested the more specific hypotheses that diagnostic parameters split along effector (lip vs. tongue) or functional (speed vs. accuracy) rather than task boundaries. Our findings contradict the view that nonspeech parameters currently used in dysarthria diagnostics are congruent with diagnostic measures of speech characteristics in PWD.

Evaluation of Diadochokinesis in Greek Preschoolers With Speech Sound Disorders Using a Diadochokinetic Rates Protocol

The study aimed at evaluating the diadochokinetic (DDK) skills of Greek-speaking preschool children with phonological disorder (PD) by means of a structured evaluation protocol and at proposing cut-off points for children at risk of speech impairment. The participants were 36 children with PD and 60 typically developing (TD) peers. The groups were matched on age and gender. The PD group performed significantly slower than the TD group in all speech DDK tasks but not in the oral-motor tasks. The ROC analysis showed a statistically significant positive discrimination for all speech tasks. The internal consistency of the protocol was excellent (Cronbach’s α = .844), while complex stimuli showed a better discriminatory ability. The obtained results agree with Dodd’s classification for speech sound disorders (SSDs). Different types of speech stimuli must be included in the evaluation of DDK performance as a clinical predictor for preschoolers with SSDs who face difficulties in speech maturation.

The effects of continuous oromotor activity on speech motor learning: speech biomechanics and neurophysiologic correlates

Sustained limb motor activity has been used as a therapeutic tool for improving rehabilitation outcomes and is thought to be mediated by neuroplastic changes associated with activity-induced cortical excitability. Although prior research has reported enhancing effects of continuous chewing and swallowing activity on learning, the potential beneficial effects of sustained oromotor activity on speech improvements is not well-documented. This exploratory study was designed to examine the effects of continuous oromotor activity on subsequent speech learning. Twenty neurologically healthy young adults engaged in periods of continuous chewing and speech after which they completed a novel speech motor learning task. The motor learning task was designed to elicit improvements in accuracy and efficiency of speech performance across repetitions of eight-syllable nonwords. In addition, transcranial magnetic stimulation was used to measure the cortical silent period (cSP) of the lip motor cortex before and after the periods of continuous oromotor behaviors. All repetitions of the nonword task were recorded acoustically and kinematically using a three-dimensional motion capture system. Productions were analyzed for accuracy and duration, as well as lip movement distance and speed. A control condition estimated baseline improvement rates in speech performance. Results revealed improved speech performance following 10 min of chewing. In contrast, speech performance following 10 min of continuous speech was degraded. There was no change in the cSP as a result of either oromotor activity. The clinical implications of these findings are discussed in the context of speech rehabilitation and neuromodulation.

Oral diadochokinetic rates across languages: Multilingual speakers comparison

BACKGROUND

It is unclear whether oral diadochokinetic rate (oral-DDK) performance is affected by different languages within a multilingual country.

AIMS

This study investigated the effects of age, sex, and stimulus type (real word in L1, L2 vs. non-word) on oral-DDK rates among healthy Malaysian-Malay speakers in order to establish language- and age-sensitive norms. The second aim was to compared the nonword 'pataka' oral-DDK rates produced by Malaysian-Malay speakers on currently available normative data for Hebrew speakers and Malaysian-Mandarin speakers.

METHODS & PROCEDURES

Oral-DDK performance of 90 participants (aged 20-77 years) using nonword ('pataka'), Malay real word ('patahkan'), and English real word ('buttercake') was audio recorded. The number of syllables produced in 8 seconds was calculated. Mixed analysis of variance (ANOVA) was conducted to examine the effects of stimulus type (nonword, Malay, and English real word), sex (male, female), age (younger, 20-40 years; middle, 41-60 years; older, ≥61 years), and their interactions on the oral-DDK rate. Data obtained were also compared with the raw data of Malaysian-Mandarin and Hebrew speakers from the previous studies.

OUTCOMES & RESULTS

A normative oral-DDK rate has been established for healthy Malaysian-Malay speakers. The oral-DDK rate was significantly affected by stimuli (p < 0.001). Malay real word showed the slowest rate, whereas there was no significant difference between English real word and nonword. The oral-DDK rate for Malay speakers was significantly higher than Mandarin and Hebrew speakers across stimuli (all p < 0.01). Interestingly, oral-DDK rates were not affected by age group for Malay speakers.

CONCLUSIONS & IMPLICATIONS

Stimuli type and language affect the oral-DDK rate, indicating that speech-language therapists should consider using language-specific norms when assessing multilingual speakers.

WHAT THIS PAPER ADDS

What is already known on the subject Age, sex, and language are factors that need to be considered when developing oral-DDK normative protocol. It is unclear whether oral-DDK performance is affected by different languages within a multilingual country. What this paper adds to existing knowledge No ageing effect across real word versus nonword on oral-DDK performance was observed among Malaysian-Malay speakers, contrasting with current available literature that speech movements slow down as we age. Additionally, Malaysian-Malay speakers have faster oral-DDK rates than Malaysian-Mandarin and Hebrew speakers across all stimuli. What are the potential or actual clinical implications of this work? Establishing normative data of different languages will enable speech-language therapists to select the appropriate reference dataset based on the language mastery of these multilingual speakers.

Oral-diadochokinetic rates among healthy Malaysian-Mandarin speakers: A cross linguistic comparison

PURPOSE

This study examined the effects of non-word versus real word, age, and gender on oral-DDK rates among healthy Malaysian-Mandarin speakers. Comparison between non-word of Malaysian-Mandarin and Hebrew speakers was examined.

METHOD

One-hundred and seventeen speakers (18-83 years old, 46% men) were audio-recorded while performing non-word (repetition of "pataka") and real-word oral-DDK tasks ("butter cake" and " ([p^ha4t^ha1k^han4])"). The number of syllables produced in 8 seconds was counted from the audio recording to derive the oral-DDK rates. A MANOVA was conducted to compare the rates between age groups (young = 18-40 years, n = 56; middle = 41-60 years, n = 39; older = 61-83 years, n = 22) and gender. In a second analysis, "pataka" results were compared between this study and previous findings with Hebrew speakers.

RESULT

No gender effects were found. However, rates significantly decreased with age (p < 0.001). Repetition of real words was faster than that of non-words - English words (5.55 ± 1.19 syllables/s) > non-words (5.29 ± 1.23) > Mandarin words (4.91 ± 1.13). Malaysian-Mandarin speakers performed slower than Hebrew speakers on "pataka" task.

CONCLUSION

Aging has a large impact on oromotor functions, indicating that speech-language pathologists should consider using age-adjusted norms.

Complexity-Dependent Modulations of Beta Oscillations for Verbal and Nonverbal Movements

Purpose The planning and execution of motor behaviors require coordination of neurons that are established through synchronization of neural activity. Movements are typically preceded by event-related desynchronization (ERD) in the beta range (15-30 Hz) primarily localized in the motor cortex, while movement onset is associated with event-related synchronization (ERS). It is hypothesized that ERD is important for movement preparation and execution, and ERS serves to inhibit movement and update the motor plan. The primary objective of this study was to determine to what extent movement-related oscillatory brain patterns (ERD and ERS) during verbal and nonverbal tasks may be affected differentially by variations in task complexity. Method Seventeen right-handed adult participants (nine women, eight men; M _age = 25.8 years, SD = 5.13) completed a sequential button press and verbal task. The final analyses included data for 15 participants for the nonverbal task and 13 for the verbal task. Both tasks consisted of two complexity levels: simple and complex sequences. Magnetoencephalography was used to record modulations in beta band brain oscillations during task performance. Results Both the verbal and button press tasks were characterized by significant premovement ERD and postmovement ERS. However, only simple sequences showed a distinct transient synchronization during the premovement phase of the task. Differences between the two tasks were reflected in both latency and peak amplitude of ERD and ERS, as well as in lateralization of oscillations. Conclusions Both verbal and nonverbal movements showed a significant desynchronization of beta oscillations during the movement preparation and holding phase and a resynchronization upon movement termination. Importantly, the premovement phase for simple but not complex tasks was characterized by a transient partial synchronization. In addition, the data revealed significant differences between the two tasks in terms of lateralization of oscillatory modulations. Our findings suggest that, while data from the general motor control research can inform our understanding of speech motor control, significant differences exist between the two motor systems that caution against overgeneralization of underlying neural control processes.

Spatiotemporal Control of Articulation During Speech and Speechlike Tasks in Amyotrophic Lateral Sclerosis

Purpose This study examined the articulatory control of speech and speechlike tasks in individuals with amyotrophic lateral sclerosis (ALS) and neurologically healthy individuals with the aim to identify the most useful set of articulatory features and tasks for assessing bulbar motor involvement in ALS. Method Tongue and jaw kinematics were recorded in 12 individuals with bulbar ALS and 10 healthy controls during a speech task and two speechlike tasks (i.e., alternating motion rate [AMR], sequential motion rate [SMR]). Eight articulatory features were derived for each participant per task, including the range, maximum speed, and acceleration time of tongue and jaw movements as well as the coupling and timing between tongue and jaw movements. The effects of task (i.e., AMR, SMR, speech) and group (i.e., ALS, control) on these articulatory features were evaluated. For each feature, the task that yielded the largest difference between the ALS and control groups was identified. The diagnostic efficacy of these task-specific features was assessed using the receiver operating characteristic analysis; the relation of these task-specific features to a well-established bulbar severity index-speaking rate-was determined using Spearman's rank correlation. Results Seven task-specific articulatory features were identified, including (a) tongue and jaw acceleration time during the AMR task, (b) tongue-jaw coupling during the SMR task, and (c) range of tongue movement, maximum tongue and jaw speed, and temporal lag between tongue and jaw movements during the speech task. Among these features, tongue and jaw acceleration time and their temporal lag showed relatively high accuracy (i.e., 0.83-0.95) in differentiating individuals with ALS from healthy controls. Range of tongue movement and maximum tongue and jaw speed showed significant correlations with speaking rate. Conclusion Findings provided preliminary evidence for the utility of task-specific articulatory measurements as a novel quantitative assessment to detect and predict bulbar motor involvement in ALS.

Maximum Speech Performance and Executive Control in Young Adult Speakers

Purpose This study investigated whether maximum speech performance, more specifically, the ability to rapidly alternate between similar syllables during speech production, is associated with executive control abilities in a nonclinical young adult population. Method Seventy-eight young adult participants completed two speech tasks, both operationalized as maximum performance tasks, to index their articulatory control: a diadochokinetic (DDK) task with nonword and real-word syllable sequences and a tongue-twister task. Additionally, participants completed three cognitive tasks, each covering one element of executive control (a Flanker interference task to index inhibitory control, a letter-number switching task to index cognitive switching, and an operation span task to index updating of working memory). Linear mixed-effects models were fitted to investigate how well maximum speech performance measures can be predicted by elements of executive control. Results Participants' cognitive switching ability was associated with their accuracy in both the DDK and tongue-twister speech tasks. Additionally, nonword DDK accuracy was more strongly associated with executive control than real-word DDK accuracy (which has to be interpreted with caution). None of the executive control abilities related to the maximum rates at which participants performed the two speech tasks. Conclusion These results underscore the association between maximum speech performance and executive control (cognitive switching in particular).

Neuromotor Control of Speech and Speechlike Tasks: Implications From Articulatory Gestures

Purpose

This study aimed to provide a preliminary examination of the articulatory control of speech and speechlike tasks based on a gestural framework and identify shared and task-specific articulatory factors in speech and speechlike tasks.

Method

Ten healthy participants performed two speechlike tasks (i.e., alternating motion rate [AMR] and sequential motion rate [SMR]) and three speech tasks (i.e., reading of “clever Kim called the cat clinic” at the regular, fast, and slow rates) that varied in phonological complexity and rate. Articulatory kinematics were recorded using an electromagnetic kinematic tracking system (Wave, Northern Digital Inc.). Based on the gestural framework for articulatory phonology, the gestures of tongue body and lips were derived from the kinematic data. These gestures were subjected to a fine-grained analysis, which extracted (a) four gestural features (i.e., range of magnitude [ROM], frequency [Freq], acceleration time, and maximum speed [maxSpd]) for the tongue body gesture; (b) three intergestural measures including the peak intergestural coherence (InterCOH), frequency at which the peak intergestural coherence occurs (Freq_InterCOH), and the mean absolute relative phase between the tongue body and lip gestures; and (c) three intragestural (i.e., interarticulator) measures including the peak intragestural coherence (IntraCOH), Freq_IntraCOH, and mean absolute relative phase between the tongue body and the jaw, which are the component articulators that underlie the tongue body gesture. In addition, the performance rate for each task was also derived. The effects of task and sex on all the articulatory and behavioral measures were examined using mixed-design analysis of variance followed by post hoc pairwise comparisons across tasks.

Results

Task had a significant effect on performance rate, ROM, Freq, maxSpd, InterCOH, Freq_InterCOH, IntraCOH, and Freq_IntraCOH. Compared to the speech tasks, the AMR task showed a decrease in ROM and increases in Freq, InterCOH, Freq_InterCOH, IntraCOH, and Freq_IntraCOH. The SMR task showed similar ROM, Freq, maxSpd, InterCOH, and IntraCOH as the fast and regular speech tasks.

Conclusions

The simple phonological structure and demand for rapid syllable rate for the AMR task may elicit a distinct articulatory control mechanism. Despite being a rapid nonsense syllable repetition task, the relatively complex phonological structure of the SMR task appeared to elicit a similar articulatory control mechanism as that of speech production. Based on these shared and task-specific articulatory features between speech and speechlike tasks, the clinical implications for articulatory assessment were discussed.

Clinical Reasoning for Speech Sound Disorders: Diagnosis and Intervention in Speech-Language Pathologists' Daily Practice

Purpose This study aims to give an insight in clinical reasoning (diagnosis and intervention) of speech-language pathologists (SLPs) in the Netherlands for children with speech sound disorder (SSD). Method The study featured a mixed-method (qualitative and quantitative) design. Semistructured interviews containing nondirective, open-ended questions were conducted with 33 SLPs, which were analyzed using a constant comparative analysis. Other SLPs (137) filled out a questionnaire on the same topics. Multiple-choice questions were analyzed by descriptive frequencies, while open-ended questions were analyzed thematically. Results The results indicate that SLPs use a variety of assessments to diagnose SSD, complemented by observation and, often, case history. In total, 85 different diagnostic labels were reported. The choice of intervention is based on what is appealing to the child and what matches his or her age as well as on the specific diagnosis and severity. Interventions are used for multiple speech disorders, and according to SLPs, parents play a large role in diagnostics and intervention. Conclusion These results reveal the need for (a) a clear and consistent terminology of diagnoses in the field of pediatric SSD, (b) a fast and easy-to-administer comprehensive differential diagnostic instrument in combination with an instrument to assess participation in everyday life, and (c) a tool to conduct a case history online.

Neural dynamics of speech and non-speech motor planning

As the speech apparatus is also involved in producing non-speech movements, understanding whether speech and non-speech planning are controlled by the same brain mechanisms is central to the comprehension of motor speech planning. A crucial issue is whether a specialized motor planning/control system is dedicated to speech or if the motor planning/control system is shared across oromotor behaviors. We investigated the EEG/ERP spatio-temporal dynamics of the motor planning processes preceding articulation by comparing the production of non-speech gestures matched to monosyllabic words and non-words. To isolate motor from pre-motor planning, we used a delayed production task combined with an articulatory suppression task. Results suggest that the planning processes preceding articulation for non-speech, words and non-words recruit the same neural networks but with different involvement for non-speech and speech. The results support the idea of shared motor planning/control systems for speech and non-speech but with different dynamics for each oromotor behavior.

Automated Acoustic Analysis of Oral Diadochokinesis to Assess Bulbar Motor Involvement in Amyotrophic Lateral Sclerosis

Purpose The purpose of this article was to validate a novel acoustic analysis of oral diadochokinesis (DDK) in assessing bulbar motor involvement in amyotrophic lateral sclerosis (ALS). Method An automated acoustic DDK analysis was developed, which filtered out the voice features and extracted the envelope of the acoustic waveform reflecting the temporal pattern of syllable repetitions during an oral DDK task (i.e., repetitions of /tɑ/ at the maximum rate on 1 breath). Cycle-to-cycle temporal variability (cTV) of envelope fluctuations and syllable repetition rate (sylRate) were derived from the envelope and validated against 2 kinematic measures, which are tongue movement jitter (movJitter) and alternating tongue movement rate (AMR) during the DDK task, in 16 individuals with bulbar ALS and 18 healthy controls. After the validation, cTV, sylRate, movJitter, and AMR, along with an established clinical speech measure, that is, speaking rate (SR), were compared in their ability to (a) differentiate individuals with ALS from healthy controls and (b) detect early-stage bulbar declines in ALS. Results cTV and sylRate were significantly correlated with movJitter and AMR, respectively, across individuals with ALS and healthy controls, confirming the validity of the acoustic DDK analysis in extracting the temporal DDK pattern. Among all the acoustic and kinematic DDK measures, cTV showed the highest diagnostic accuracy (i.e., 0.87) with 80% sensitivity and 94% specificity in differentiating individuals with ALS from healthy controls, which outperformed the SR measure. Moreover, cTV showed a large increase during the early disease stage, which preceded the decline of SR. Conclusions This study provided preliminary validation of a novel automated acoustic DDK analysis in extracting a useful measure, namely, cTV, for early detection of bulbar ALS. This analysis overcame a major barrier in the existing acoustic DDK analysis, which is continuous voicing between syllables that interferes with syllable structures. This approach has potential clinical applications as a novel bulbar assessment.

A Psycholinguistic Framework for Diagnosis and Treatment Planning of Developmental Speech Disorders

BACKGROUND

Differential diagnosis and treatment planning of developmental speech disorders (DSD) remains a major challenge in paediatric speech-language pathology. Different classification systems exist, in which subtypes are differentiated based on their theoretical cause and in which the definitions generally refer to speech production processes. Accordingly, various intervention methods have been developed aiming at different parts of the speech production process. Diagnostic classification in these systems, however, is primarily based on a description of behavioural speech symptoms rather than on underlying deficits.

PURPOSE

In this paper, we present a process-oriented approach to diagnosis and treatment planning of DSD. Our framework comprises two general diagnostic categories: developmental delay and developmental disorder. Within these categories, treatment goals/targets and treatment methods are formulated at the level of processes and rules/representations.

CONCLUSION

A process-oriented approach to diagnosis and treatment planning holds important advantages, offering direct leads for treatment aimed at the underlying impairment, tailored to the specific needs of the individual and adjusted to the developmental trajectory.

A Standardized Protocol for Maximum Repetition Rate Assessment in Children

BACKGROUND/AIMS

Maximum repetition rate (MRR) is often used in the assessment of speech motor performance in older children and adults. The present study aimed to evaluate a standardized protocol for MRR assessment in young children in Dutch.

METHODS

The sample included 1,524 children of 2-7 years old with no hearing difficulties and Dutch spoken in their nursery or primary school and was representative for children in the Netherlands. The MRR protocol featured mono-, tri-, and bisyllabic sequences and was computer-implemented to maximize standardization.

RESULTS

Less than 50% of the 2-year-olds could produce >1 monosyllabic sequence correctly. Children who could not correctly produce ≥2 monosyllabic sequences could not produce any of the multisyllabic sequences. The effect of instruction ("faster" and "as fast as possible") was small, and multiple attempts yielded a faster MRR in only 20% of the cases. MRRs did not show clinically relevant differences when calculated over different numbers of repeated syllables.

CONCLUSIONS

The MRR protocol is suitable for children of 3 years and older. If children cannot produce at least 2 of the monosyllabic sequences, the multisyllabic tasks should be omitted. Furthermore, all fast attempts of each sequence should be analyzed to determine the fastest MRR.

Estimates of the Prevalence of Speech and Motor Speech Disorders in Youth With 22q11.2 Deletion Syndrome

Purpose Speech sound disorders and velopharyngeal dysfunction are frequent features of 22q11.2 deletion syndrome (22q). We report the first estimate of the prevalence of motor speech disorders (MSDs) in youth with 22q. Method Seventeen children and adolescents with 22q completed an assessment protocol that included a conversational speech sample. Data reduction included phonetic transcription, perceptual speech ratings, prosody-voice coding, and acoustic analyses. Data analyses included 3 motor speech measures and a cross-classification analytic. Prevalence estimates of speech and MSDs in youth with 22q were compared with estimates in speakers with other complex neurodevelopmental disorders: Down syndrome, fragile X syndrome, and galactosemia. Results Results indicated that 58.8% of the participants with 22q met criteria for speech delay, and 82.4% of the participants met criteria for MSDs, including 29.4% with speech motor delay, 29.4% with childhood dysarthria, 11.8% with childhood apraxia of speech, and 11.8% with concurrent childhood dysarthria and childhood apraxia of speech. MSDs were not significantly associated with velopharyngeal dysfunction. Conclusions In summary, 82.4% of the participants with 22q met criteria for 1 of 4 MSDs, predominantly speech motor delay and childhood dysarthria. Cross-validation of the present findings would support viewing MSDs as a core phenotypic feature of 22q.

Automatic extraction of abnormal lip movement features from the alternating motion rate task in amyotrophic lateral sclerosis

Purpose: With the long-term goal to develop a clinically feasible tool for assessing articulatory involvement in ALS, we designed an algorithmic approach to automatically extract lip movement features during an alternating motion rate (AMR) task and assessed their efficacy for detecting and monitoring articulatory involvement in amyotrophic lateral sclerosis (ALS). Method: Twenty three spatial, temporal, and spatiotemporal AMR features were extracted from 161 samples of lip movements (139 from participants with ALS; 22 from neurologically-intact participants). The diagnostic value of these features was assessed based on their (1) sensitivity for detecting early bulbar motor involvement, and (2) associations with accepted clinical measures of bulbar disease progression. Result: Among all AMR features, two temporal features were the most affected - temporal variability and syllable frequency, which (1) showed large changes during early disease stages and (2) predicted the progression of bulbar motor involvement and speech intelligibility decline. Spatial features were in general, less sensitive to early bulbar motor involvement. Conclusions: The findings provided preliminary support for the algorithmic approach to quantifying articulatory features predictive of bulbar motor and speech decline in ALS. The differential disease effects on spatial and temporal AMR features might shed light on the mechanism of articulatory involvement during ALS progression.

Rhythmic performance in hypokinetic dysarthria: Relationship between reading, spontaneous speech and diadochokinetic tasks

•We investigated speech rhythm in people with Parkinson’s Disease (PwPD) and controls. •Even mildly affected PwPD differed from controls in their rhythmic performance. •PwPD showed less difference between reading and spontaneous speech. •Spontaneous speech highlighted more differences between speakers than reading. •DDK performance did not relate to rhythmic behaviour in connected speech.