Effects of online augmented kinematic and perceptual feedback on treatment of speech movements in apraxia of speech

Effect of Practice Structure and Feedback Frequency on Voice Motor Learning in Older Adults

OBJECTIVES

The long-term goal of this research is to advance the rehabilitation of voice disorders through the study and development of efficacious treatment regimes based upon motor learning principles. This study examined the effect of contextual interference (CI) of practice structure with knowledge of results (KR) feedback on motor learning of a novel voice task, "Twang," by hypophonic, novice, and expert older adults.

STUDY DESIGN

Prospective, randomized controlled mixed design.

METHODS

A total of 92 adults, age 55-80, recruited from the following motor skill levels: 1) Hypophonic voice; 2) Novice-untrained vocalists; 3) Expert-trained vocalists were randomly assigned to four different interventions and examined during acquisition, retention, and transfer phases of motor learning. Participants from each skill-level practiced the novel task, "Twang," according to the randomly assigned Practice Structure/KR combinations: 1) Blocked practice/100%KR; 2) Blocked practice/55% KR; 3) Random practice/100%KR; 4) Random practice/55% KR.

RESULTS

During the motor performance phase, our results mirrored those reported in the limb motor learning literature for CI: A Blocked practice structure enhanced short-term effects of motor acquisition for novice, expert, and hypophonic subjects. The only significant result for KR occurred when paired with Random Practice in the hypophonic subject group: 100% KR paired with Blocked practice increased motor performance, but degraded motor learning.

CONCLUSIONS

Fundamental motor learning principles were explored within the context of a voice training paradigm. Practice with a high CI and low frequency of KR degraded performance during short-term acquisition but enhanced long-term performance effects of motor learning. Voice clinicians and teachers may benefit by implementing motor learning theory into practice during training and treatment sessions.

Testing hypotheses about the underlying deficit of apraxia of speech through computational neural modelling with the DIVA model

Purpose: A recent behavioural experiment featuring a noise masking paradigm suggests that Apraxia of Speech (AOS) reflects a disruption of feedforward control, whereas feedback control is spared and plays a more prominent role in achieving and maintaining segmental contrasts. The present study set out to validate the interpretation of AOS as a possible feedforward impairment using computational neural modelling with the DIVA (Directions Into Velocities of Articulators) model.Method: In a series of computational simulations with the DIVA model featuring a noise-masking paradigm mimicking the behavioural experiment, we investigated the effect of a feedforward, feedback, feedforward + feedback, and an upper motor neuron dysarthria impairment on average vowel spacing and dispersion in the production of six/bVt/speech targets.Result: The simulation results indicate that the output of the model with the simulated feedforward deficit resembled the group findings for the human speakers with AOS best.Conclusion: These results provide support to the interpretation of the human observations, corroborating the notion that AOS can be conceptualised as a deficit in feedforward control.

Modelling speech motor programming and apraxia of speech in the DIVA/GODIVA neurocomputational framework

BACKGROUND

The Directions Into Velocities of Articulators (DIVA) model and its partner, the Gradient Order DIVA (GODIVA) model, provide neurobiologically grounded, computational accounts of speech motor control and motor sequencing, with applications for the study and treatment of neurological motor speech disorders.

AIMS

In this review, we provide an overview of the DIVA and GODIVA models and how they explain the interface between phonological and motor planning systems to build on previous models and provide a mechanistic accounting of apraxia of speech (AOS), a disorder of speech motor programming.

MAIN CONTRIBUTION

Combined, the DIVA and GODIVA models account for both the segmental and suprasegmental features that define AOS via damage to (i) a speech sound map, hypothesized to reside in left ventral premotor cortex, (ii) a phonological content buffer hypothesized to reside in left posterior inferior frontal sulcus, and/or (iii) the axonal projections between these regions. This account is in line with a large body of behavioural work, and it unifies several prior theoretical accounts of AOS.

CONCLUSIONS

The DIVA and GODIVA models provide an integrated framework for the generation and testing of both behavioural and neuroimaging hypotheses about the underlying neural mechanisms responsible for motor programming in typical speakers and in speakers with AOS.

Acquired Apraxia of Speech: Comparison of Electropalatography Treatment and Sound Production Treatment

Purpose This investigation compared 2 treatment approaches for acquired apraxia of speech. The effects of a treatment that uses an articulatory-kinematic approach in conjunction with visual biofeedback (VBFB) via electropalatography (EPG) were compared to Sound Production Treatment (SPT), an established behavioral treatment that is also an articulatory-kinematic approach. Method A multiple baseline design across behaviors and participants was used with 2 participants with chronic apraxia of speech and aphasia. Accuracy of target speech sounds in treated and untreated words or phrases in probe sessions served as the dependent variable. The effects of 2 treatments based on an articulatory-kinematic approach were compared: (a) VBFB via EPG and (b) SPT. The order of treatments was counterbalanced across participants. Results Positive changes in articulatory accuracy were observed for SPT and VBFB treatment via EPG. Generalization to untreated stimulus items composed of treated speech sounds was also positive for both treatments. However, participants achieved greater articulatory accuracy with SPT during treatment and better long-term maintenance. Discussion Both treatment approaches resulted in improved speech production accuracy, but gains were greater for SPT. However, further research with additional participants is needed due to the small sample size included in this investigation.

Principles of Motor Learning in Classical Singing Teaching

INTRODUCTION

Classical singing is a complex and multifaceted skill that requires the amalgamation of multiple cognitive, perceptual and motor functions. The teaching of classical singing is consequently a unique skill that holds further complexity. The singer is required to achieve and maintain consistently high performance development of a specific motor activity, much like the sports athlete. This pilot study examines a method of using the principles of motor learning to more objectively and reliably investigate the teaching behaviors of classical singing teachers. Such a method may establish a nexus between empirical research, teaching quality and learning outcomes in music performance education.

METHOD

A total of 12 participants were recruited from two Australian conservatoria of music. All participants were fluent in English at tertiary level. Participants included four classical singing teachers and eight classical singing students over the age of 18 years. Eight one-to-one singing lessons between the teacher and student were audio-visually recorded. Content analysis was conducted on the observational data. The principles of motor learning were used as a behavioral framework protocol to allow for the systematic identification of teaching behavior.

RESULTS

Results presented various findings regarding teaching behaviors in one-to-one classical singing lessons in higher music education. Key findings included (a) common use of instruction, feedback, modeling, and other behaviors (b) uncommon use of motivation, explanation, and perceptual training behaviors, (c) higher use of knowledge of results than knowledge of performance feedback behaviors, (d) high routine use of instruction, modeling, and feedback behaviors each time a student attempted a task, (e) common use of other suggested teachers use behaviors unidentifiable by the behavioral protocol, and (f) the principles of motor learning appear to be a reliable framework for the identification of teaching behaviors in this field.

CONCLUSION

This study may have implications for how teachers administer and govern their behaviors in one-to-one classical singing lessons. The principles of motor learning may encourage a nexus between empirical research, teaching quality, and learning outcomes. Furthermore, this study provides recommendations for future research on systematically improving teaching and learning in this field.

Treating Speech Movement Hypokinesia in Parkinson's Disease: Does Movement Size Matter?

Purpose

This study evaluates the effects of a novel speech therapy program that uses a verbal cue and gamified augmented visual feedback regarding tongue movements to address articulatory hypokinesia during speech in individuals with Parkinson's disease (PD).

Method

Five participants with PD participated in an ABA single-subject design study. The treatment aimed to increase tongue movement size using a combination of a verbal cue and augmented visual feedback and was conducted in 10 45-min sessions over 5 weeks. The presence of visual feedback was manipulated during treatment. Articulatory working space of the tongue was the primary outcome measure and was examined during treatment and in cued and uncued sentences pre- and posttreatment. Changes in speech intelligibility in response to a verbal cue pre- and posttreatment were also examined.

Results

During treatment, 4/5 participants showed a beneficial effect of visual feedback on tongue articulatory working space. At the end of the treatment, they used larger tongue movements when cued, relative to their pretreatment performance. None of the participants, however, generalized the effect to the uncued sentences. Speech intelligibility of cued sentences was judged as superior posttreatment only in a single participant.

Conclusions

This study demonstrated that using an augmented visual feedback approach is beneficial, beyond a verbal cue alone, in addressing articulatory hypokinesia in individuals with PD. An optimal degree of articulatory expansion might, however, be required to elicit a speech intelligibility benefit.

Role of Constant, Random and Blocked Practice in an Electromyography-Based Oral Motor Learning Task

PURPOSE

The role of principles of motor learning (PMLs) in speech has received much attention in the past decade. Oral motor learning, however, has not received similar consideration. This study evaluated the role of three practice conditions in an oral motor tracking task.

METHOD

Forty-five healthy adult participants were randomly and equally assigned to one of three practice conditions (constant, blocked, and random) and participated in an electromyography-based task. The study consisted of four sessions, at one session a day for four consecutive days. The first three days sessions included a practice phase, with immediate visual feedback, and an immediate retention phase, without visual feedback. The fourth session did not include practice, but only delayed retention testing, lasting 10-15 minutes, without visual feedback.

RESULTS

Random group participants performed better than participants in constant and blocked practice conditions on all the four days. Constant group participants demonstrated superior learning over blocked group participants only on day 4.

CONCLUSION

Findings indicate that random practice facilitates oral motor learning, which is in line with limb/speech motor learning literature. Future research should systematically investigate the outcomes of random practice as a function of different oral and speech-based tasks.

The Use of Electropalatography in the Treatment of Acquired Apraxia of Speech

PURPOSE

This investigation was designed to examine the effects of an articulatory-kinematic treatment in conjunction with visual biofeedback (VBFB) via electropalatography (EPG) on the accuracy of articulation for acquired apraxia of speech (AOS).

METHOD

A multiple-baseline design across participants and behaviors was used with 4 individuals with chronic AOS and aphasia. Accuracy of target speech sounds in treated and untreated phrases in probe sessions served as the dependent variable. Participants received an articulatory-kinematic treatment in combination with VBFB, which was sequentially applied to 3 stimulus sets composed of 2-word phrases with a target speech sound for each set.

RESULTS

Positive changes in articulatory accuracy were observed for participants for the majority of treated speech sounds. Also, there was generalization to untreated phrases for most trained speech sounds. Two participants had better long-term maintenance of treated speech sounds in both trained and untrained stimuli.

CONCLUSIONS

Findings indicate EPG may be a potential treatment tool for AOS. It appears that individuals with AOS can benefit from VBFB via EPG in improving articulatory accuracy. However, further research is needed to determine if VBFB is more advantageous than behavioral treatments that have been proven effective in improving speech production for speakers with AOS.

Treatment for Acquired Apraxia of Speech: A Systematic Review of Intervention Research Between 2004 and 2012

OBJECTIVES

The aim was for the appointed committee of the Academy of Neurological Communication Disorders and Sciences to conduct a systematic review of published intervention studies of acquired apraxia of speech (AOS), updating the previous committee's review article from 2006.

METHOD

A systematic search of 11 databases identified 215 articles, with 26 meeting inclusion criteria of (a) stating intention to measure effects of treatment on AOS and (b) data representing treatment effects for at least 1 individual stated to have AOS.

RESULTS

All studies involved within-participant experimental designs, with sample sizes of 1 to 44 (median = 1). Confidence in diagnosis was rated high to reasonable in 18 of 26 studies. Most studies (24/26) reported on articulatory-kinematic approaches; 2 applied rhythm/rate control methods. Six studies had sufficient experimental control for Class III rating according to the Clinical Practice Guidelines Process Manual (American Academy of Neurology, 2011), with 15 others satisfying all criteria for Class III except use of independent or objective outcome measurement.

CONCLUSIONS

The most important global clinical conclusion from this review is that the weight of evidence supports a strong effect for both articulatory-kinematic and rate/rhythm approaches to AOS treatment. The quantity of work, experimental rigor, and reporting of diagnostic criteria continue to improve and strengthen confidence in the corpus of research.

Audiological findings in aphasic patients after stroke

Objective

To outline the audiological findings of aphasic patients after cerebrovascular accidents.

Methods

This is a cross-sectional study performed between March 2011 and August 2012 in the Speech, Language, and Hearing Pathology Department of the Universidade Federal de São Paulo. A total of 43 aphasic subjects (27 men) were referred for audiological evaluation after stroke, with mean age of 54.48 years. Basic audiological evaluation tests were performed, including pure tone audiometry, speech audiometry (speech recognition threshold and word recognition score), immittance measures (tympanometry and contralateral acoustic reflex), and transient otoacoustic emissions.

Results

Sensorineural hearing loss was prevalent (78.6%). Speech recognition threshold and word recognition score were not obtained in some patients because they were unable to perform the task. Hearing loss was a common finding in this population.

Conclusion

Comprehension and/or oral emission disruptions in aphasic patients after stroke compromised conventional speech audiometry, resulting in the need for changes in the evaluation procedures for these patients.

Motor-based intervention protocols in treatment of childhood apraxia of speech (CAS)

This paper reviews current trends in treatment for childhood apraxia of speech (CAS), with a particular emphasis on motor-based intervention protocols. The paper first briefly discusses how CAS fits into the typology of speech sound disorders, followed by a discussion of the potential relevance of principles derived from the motor learning literature for CAS treatment. Next, different motor-based treatment protocols are reviewed, along with their evidence base. The paper concludes with a summary and discussion of future research needs.

Advances in the Treatment for Acquired Apraxia of Speech

Treatments for acquired apraxia of speech (AOS) have a modest, but growing evidence base. A substantial number of treatment investigations have been reported since the publication of the first AOS treatment guidelines (Wambaugh, Duffy, McNeil, Robin, & Rogers, 2006a; 2006b). The authors have provided an overview of more recent AOS treatment evidence, along with a description of important advances, emerging trends, and new directions in the treatment of AOS.

The effect of anatomic factors on tongue position variability during consonants

PURPOSE

This study sought to investigate the effect of palate morphology and anthropometric measures of the head on positional variability of the tongue during consonants.

METHOD

An electromagnetic tracking system was used to record tongue movements of 21 adults. Each talker produced a series of symmetrical VCV syllables containing one of the consonants /t, d, s, z, , t, k, g, j/ and corner vowels /i, a, u/. Distributions of x, y, and z coordinates at maximum tongue elevation were used to represent tongue position variability across contexts. Anthropometric palate and head measures were also obtained.

RESULTS

Positional variability of the tongue differed between the front (e.g., alveolar and post-alveolar) and back (velar) consonant groups. A correlational analysis showed that tongue position variability of the front consonants was explained, to a degree, by palate curvature and palate length. The variability of the back consonants was not explained by any structural measures.

CONCLUSION

Palate morphology needs to be taken into account when making observations regarding the extent of tongue position variability during consonants in research and in achieving clinical goals.

Single-case experimental designs: a systematic review of published research and current standards

This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have precluded widespread implementation and acceptance of the SCED as a viable complementary methodology to the predominant group design. This article includes a description of the research design, measurement, and analysis domains distinctive to the SCED; a discussion of the results within the framework of contemporary standards and guidelines in the field; and a presentation of updated benchmarks for key characteristics (e.g., baseline sampling, method of analysis), and overall, it provides researchers and reviewers with a resource for conducting and evaluating SCED research. The results of the systematic review of 409 studies suggest that recently published SCED research is largely in accordance with contemporary criteria for experimental quality. Analytic method emerged as an area of discord. Comparison of the findings of this review with historical estimates of the use of statistical analysis indicates an upward trend, but visual analysis remains the most common analytic method and also garners the most support among those entities providing SCED standards. Although consensus exists along key dimensions of single-case research design, and researchers appear to be practicing within these parameters, there remains a need for further evaluation of assessment and sampling techniques and data analytic methods.

Positional targets for lingual consonants defined using electromagnetic articulography

The study examined the positional targets for lingual consonants defined using a point-parameterized approach with Wave (NDI, Waterloo, ON, Canada). The overall goal was to determine which consonants had unique tongue positions with respect to other consonants. Nineteen talkers repeated vowel-consonant-vowel (VCV) syllables that included consonants /t, d, s, z, , k, g/ in symmetrical vowel contexts /i, u, a/, embedded in a carrier phrase. Target regions for each consonant, characterized in terms of x,y,z tongue positions at the point of maximum tongue elevation, were extracted. Distances and overlaps were computed between all consonant pairs and compared to the distances and overlaps of their contextual targets. Cognates and postalveolar homorganics were found to share the location of their target regions. On average, alveolar stops showed distinctively different target regions than alveolar fricatives, which in turn showed different target region locations than the postalveolar consonants. Across talker variability in target locations was partially explained by differences in habitual speaking rate and hard palate characteristics.

Conditions of Practice and Feedback in Treatment for Apraxia of Speech

Purpose: The purpose of this article is to review a number of conditions of practice and feedback (sometimes referred to as principles of motor learning) in relation to treatment for apraxia of speech (AOS).

Methods: A narrative review of pertinent literature is provided.

Conclusions: Although there has been little systematic study of these conditions in treatment for AOS, the emerging evidence is consistent with the idea that conditions of practice and feedback have similar effects in treatment for AOS as those seen in the motor learning literature.