Computer Games for Motor Speech Rehabilitation

This research investigates the problem of creating a system for interactive digital visual feedback of articulator kinematics measures for speech rehabilitation. Recent technology provides precise non-line-of-sight positional tracking of small sensors which affords exploration into the motion of articulators such as the tongue. By utilizing recent game development technology, articulation kinematics can be visualized in realtime. Using these technologies the basis for an interactive rehabilitation system is formed. The system is posed as both a research apparatus and a potential clinical rehabilitation delivery system. As such, this system provides an extensible software and design architecture for the creation of interactive feedback visualizations and kinematic speech metrics as well as a clinical research front end for the creation and delivery of speech motor rehabilitation protocols

The Relationship of Somatosensory Perception and Fine-Force Control in the Adult Human Orofacial System

The orofacial area stands apart from other body systems in that it possesses a unique performance anatomy whereby oral musculature inserts directly into the underlying cutaneous skin, allowing for the generation of complex three-dimensional deformations of the orofacial system. This anatomical substrate provides for the tight temporal synchrony between self-generated cutaneous somatosensation and oromotor control during functional behaviors in this region and provides the necessary feedback needed to learn and maintain skilled orofacial behaviors. The Directions into Velocity of Articulators (DIVA) model highlights the importance of the bidirectional relationship between sensation and production in the orofacial region in children learning speech. This relationship has not been as well-established in the adult orofacial system. The purpose of this observational study was to begin assessing the perception-action relationship in healthy adults and to describe how this relationship may be altered as a function of healthy aging. This study was designed to determine the correspondence between orofacial cutaneous perception using vibrotactile detection thresholds (VDT) and low-level static and dynamic force control tasks in three representative age cohorts. Correlational relationships among measures of somatosensory capacity and low-level skilled orofacial force control were determined for 60 adults (19-84 years). Significant correlational relationships were identified using non-parametric Spearman’s correlations with an alpha at 0.1 between the 5 Hz test probe and several 0.5 N low-level force control assessments in the static and slow ramp-and-hold condition. These findings indicate that as vibrotactile detection thresholds increase (labial sensation decreases), ability to maintain a low-level force endpoint decreases. Group data was analyzed using non-parametric Kruskal-Wallis tests and identified significant differences between the 5 Hz test frequency probe and various 0.5 N skilled force assessments for group variables such as age, pure tone hearing assessments, sex, speech usage and smoking history. Future studies will begin the processing of modeling this complex multivariate relationship in healthy individuals before moving to a disordered population

Speech articulation in children with Williams syndrome or 7q11.23 duplication syndrome.

Williams syndrome (WS) and 7q11.23 duplication syndrome (Dup7) are associated with communication disorders (Huffman et al., 2013). However, articulatory accuracy has not been systematically examined in these populations. The dissertation involved two studies. Using standardized citation assessment, Study 1 addressed articulatory accuracy with regard to age norms and differences between groups. Results indicated that for both groups, (a) consonant accuracy was significantly below expectations, (b) older children pronounced consonants with significantly better accuracy than younger children, (c) children with IQs at or above 70 earned significantly higher articulation standard scores, and (d) for particular groups of consonant sounds, arranged as a function of features of articulation, significant differences were found across consonant groups for (c.1) expected period of acquisition in development, (c.2) articulatory place of production, (c.3) articulatory manner of production, and (c.4) movement transition across consonants within clusters. Study 2 addressed variance relations among speech articulatory accuracy, phonological processing, and particular cognitive and linguistic measures. Articulatory accuracy was shown moderately, to strongly, related to each study variable. For the children with WS, articulatory accuracy contributed unique variance to phonological processing beyond that contributed by verbal short-term memory, spatial ability, and the combined factor of lexical understanding and use. Overall, the results showed children in both groups were significant delayed in consonantal development. Patterns of articulatory accuracy did not differ greatly from those of younger, typically developing children. Furthermore, the findings demonstrated positive relations among articulatory accuracy, phonological processing, intellectual abilities, and vocabulary abilities for children with these syndromes

The effectiveness of PROMPT therapy for children with cerebral palsy

The purpose of this study is to evaluate the effectiveness of a motor speech treatment approach (PROMPT) in the management of motor-speech impairment in children with cerebral palsy. Two main objectives were addressed: (1) to evaluate changes in speech intelligibility and, (2) evaluate changes in kinematic movements of the jaw and lips using three dimensional (3D) motion analysis.A single subject multiple-baseline-across-participants research design, with four phases: Baseline (A1), two intervention phases (B and C) and maintenance (A2), was implemented.Six participants, aged 3-to-11-years (3 boys, 3 girls) with moderate to severe speech impairment were recruited through The Centre for Cerebral Palsy, Western Australia (TCCP). Inclusion criteria were: diagnosis of cerebral palsy, age 3 – 14 years, stable head control (supported or independent), spontaneous use of at least 15 words, speech impairment ≥1.5 standard deviations, hearing loss no greater than 25dB, developmental quotient ≥70 (Leiter-Brief International Performance Scale R) and no previous exposure to PROMPT. Thirteen typically-developing peers were recruited to compare the trend of kinematic changes in jaw and lip movements to those of the children with cerebral palsy.Upon achievement of a stable baseline, participants completed two intervention phases both of 10 weeks duration. Therapist fidelity to the PROMPT approach was determined by a blinded, independent PROMPT Instructor.Perceptual outcome measures included the administration of weekly speech probes, containing trained and untrained vocabulary at the two targeted levels of intervention plus an additional level. These were analysed for both perceptual accuracy (PA) and the motor speech movement parameter. End of phase measures included: 1. Changes in phonetic accuracy as measured using a measure of percentage phonemes correct; 2. Speech intelligibility measures, using a standardised assessment tool; and 3. Changes to activity/participation using the Canadian Occupational Performance Measure (COPM).Kinematic data were collected at the end of each study phase using 3D motion analysis (Vicon Motus 9.1). This involved the collection of jaw and lip measurements of distance, duration and velocity, during the production of 11 untrained stimulus words. The words contained vowels that spanned the articulatory space and represented motor-speech movement patterns at the level of mandibular and labial-facial control, as classified according to the PROMPT motor speech hierarchy.Analysis of the speech probe data showed all participants recorded a statistically significant improvement. Between phases A1-B and B-C 6/6 and 4/6 participants respectively, recorded a statistically significant increase in performance level on the motor speech movement patterns (MSMPs) targeted during the training of that intervention priority (IP). The data further show that five participants (one participant was lost to follow-up) achieved a statistically significant increase at 12- weeks post-intervention as compared to baseline (phase A1).Four participants achieved a statistically significant increase in performance level in the PA of the speech probes of both IP1 and IP2 between phases A1-B. Whilst only one participant recorded a statistically significant increase in PA between phases BC, five participants achieved a statistically significant increase in IP2 between phases A1-C. The data further show all participants achieved a statistically significant increase in PA on both intervention priorities at 12-weeks post-intervention. All participants recorded data that indicated improved perceptual accuracy across the study phases. This was indicated by a statistically significant increase in the percentage phonemes correct scores F(3,18) = 5.55, p<.05.All participants achieved improved speech intelligibility. Five participants recorded an increase in speech intelligibility greater than 14% at the end of the first intervention (phase B). Continued improvement was observed for 5 participants at the end of the second intervention (phase C)

Sensorimotor Modulations by Cognitive Processes During Accurate Speech Discrimination: An EEG Investigation of Dorsal Stream Processing

Internal models mediate the transmission of information between anterior and posterior regions of the dorsal stream in support of speech perception, though it remains unclear how this mechanism responds to cognitive processes in service of task demands. The purpose of the current study was to identify the influences of attention and working memory on sensorimotor activity across the dorsal stream during speech discrimination, with set size and signal clarity employed to modulate stimulus predictability and the time course of increased task demands, respectively. Independent Component Analysis of 64–channel EEG data identified bilateral sensorimotor mu and auditory alpha components from a cohort of 42 participants, indexing activity from anterior (mu) and posterior (auditory) aspects of the dorsal stream. Time frequency (ERSP) analysis evaluated task-related changes in focal activation patterns with phase coherence measures employed to track patterns of information flow across the dorsal stream. ERSP decomposition of mu clusters revealed event-related desynchronization (ERD) in beta and alpha bands, which were interpreted as evidence of forward (beta) and inverse (alpha) internal modeling across the time course of perception events. Stronger pre-stimulus mu alpha ERD in small set discrimination tasks was interpreted as more efficient attentional allocation due to the reduced sensory search space enabled by predictable stimuli. Mu-alpha and mu-beta ERD in peri- and post-stimulus periods were interpreted within the framework of Analysis by Synthesis as evidence of working memory activity for stimulus processing and maintenance, with weaker activity in degraded conditions suggesting that covert rehearsal mechanisms are sensitive to the quality of the stimulus being retained in working memory. Similar ERSP patterns across conditions despite the differences in stimulus predictability and clarity, suggest that subjects may have adapted to tasks. In light of this, future studies of sensorimotor processing should consider the ecological validity of the tasks employed, as well as the larger cognitive environment in which tasks are performed. The absence of interpretable patterns of mu-auditory coherence modulation across the time course of speech discrimination highlights the need for more sensitive analyses to probe dorsal stream connectivity

The production and perception of peripheral geminate/singleton coronal stop contrasts in Arabic

Gemination is typologically common word-medially but is rare at the periphery of the word (word-initially and -finally). In line with this observation, prior research on production and perception of gemination has focused primarily on medial gemination. Much less is known about the production and perception of peripheral gemination. This PhD thesis reports on comprehensive articulatory, acoustic and perceptual investigations of geminate-singleton contrasts according to the position of the contrast in the word and in the utterance. The production component of the project investigated the articulatory and acoustic features of medial and peripheral gemination of voiced and voiceless coronal stops in Modern standard Arabic and regional Arabic vernacular dialects, as produced by speakers from two disparate and geographically distant countries, Morocco and Lebanon. The perceptual experiment investigated how standard and dialectal Arabic gemination contrasts in each word position were categorised and discriminated by three groups of non-native listeners, each differing in their native language experience with gemination at different word positions. The first experiment used ultrasound and acoustic recordings to address the extent to which word-initial gemination in Moroccan and Lebanese dialectal Arabic is maintained, as well as the articulatory and acoustic variability of the contrast according to the position of the gemination contrast in the utterance (initial vs. medial) and between the two dialects. The second experiment compared the production of word-medial and -final gemination in Modern Standard Arabic as produced by Moroccan and Lebanese speakers. The aim of the perceptual experiment was to disentangle the contribution of phonological and phonetic effects of the listeners’ native languages on the categorisation and discrimination of non-lexical Moroccan gemination by three groups of non-native listeners varying in their phonological (native Lebanese group and heritage Lebanese group, for whom Moroccan is unintelligible, i.e., non-native language) and phonetic-only (native English group) experience with gemination across the three word positions. The findings in this thesis constitute important contributions about positional and dialectal effects on the production and perception of gemination contrasts, going beyond medial gemination (which was mainly included as control) and illuminating in particular the typologically rare peripheral gemination

Temporal and Aerodynamic Aspects of Velopharyngeal Coarticulation: Effects of Age, Gender and Vowel Height

Previous studies on the normal patterns of velopharyngeal coarticulation did not provide a multidimensional description of the phenomenon. The primary objective of this study was to determine the effects of age, gender and vowel height on the temporal and aerodynamic aspects of nasal airflow segments related to velar coarticulation in the normal speech of children and adults. A secondary objective was to determine the within speaker variability of the segments. Speakers consisted of 20 children between the ages of 5 and 7 years, 20 children between 9 and 11 years and 20 adult speakers 18 years or older. Nasal and oral air flows were collected from the participants using partitioned oro-nasal masks during the production of vowel-nasal-vowel sequences (VNV) including /ini/ and /ana/ embedded in two carrier phrases. Temporal and aerodynamic measurements were obtained for anticipatory and carryover nasal airflow for (VNV) sequences including absolute (in seconds) and proportional duration, as well as the volume of nasal airflow (in milliliters) and the ratio of nasal to oral-plus-nasal airflow volume. A mixed design 3 x 2 x 2 x 2 ANOVA procedure was used to determine the effects of age group, gender, vowel height and production level (type of carrier phrase) on temporal and aerodynamic aspects of anticipatory and carryover nasal airflow. In addition, coefficient of variation (CV) was computed for both temporal and aerodynamic measures as an index to speaker\u27s variability. Group Analysis of Variance 3 x 2 ANOVA procedures were used to determine the effect of age group, gender, or both on within speaker variability for all temporal and aerodynamic measurements. The results of the analysis suggest a significant age effect (p \u3c .001) on both temporal aspects and on the absolute volume (ml) of anticipatory nasal airflow. Duration, absolutely (sec) and proportionally, and volume of nasal airflow (ml) decreased with increasing age. No significant age effect was found for carryover nasal airflow. However, a significant interaction between gender and vowel height was found. Female speakers produced longer duration than male speakers on high vowel contexts, and women produced greater volume of nasal airflow (ml) and greater ratio of nasal to oral-plus-nasal airflow. A significant production level effect was also found. Generally, all speakers exhibited reduced absolute (sec) and proportional duration as well as reduced nasal airflow volume (ml) when the carrier phrase contained \u27say\u27 preceding the VNV sequence compared to the one without \u27say\u27. Results of the CVs analysis showed main effect of age as well as age and gender interaction. Results indicate a reduction on variability with increasing age. Older boys and men exhibited greater variability than older girls and women particularly on high vowel context. Results of the study indicate that children and adults produce distinct patterns of temporal and aerodynamic aspect of anticipatory nasal airflow. Findings were consistent with previous studies that reduction in duration of speech segment and reduction in variability is a general pattern of speech development. It is also suggested that subtle gender differences in oral-pharyngeal anatomy as well as vowel-specific production patterns may explain the gender difference on high vowels. Results of the study were discussed in the light of Gestural Phonology view of speech development and velar movement. Clinical implications were suggested for the diagnosis and treatment of patients with velopharyngeal dysfunction

Speech Production Analyses: Characterizing Typical Development versus Childhood Apraxia of Speech

Childhood Apraxia of Speech (CAS) is a controversial diagnosis that is frequently based on clinical perceptions, with treatment success based on the same perceptual measures. Because additional, less abstract diagnostic and treatment outcome procedures are needed, a series of quantitative trials were chosen for the current research to potentially assist in the diagnosis and evaluation of treatment for those with CAS. The study included two participants, one child with typically developing (TD) speech and one diagnosed and verified by current protocols as having CAS. Kinematic and acoustic measures were used to calculate spatiotemporal index, speech-pause time, and lexical stress. The spatiotemporal index was factored using kinematic data and computer-based algorithms. Acoustic data were used to evaluate speech versus pause time as well as lexical stress. Speech-pause time was calculated by measuring speech time in comparison with pause times both between and within words. Lexical stress was calculated by computing ratios involving vowel length, mean frequency, and mean amplitude of the first syllable over the second syllable.   The participant with CAS displayed greater inconsistency with both the lower and upper lip during repetitions of "Buy Bobby a puppy"; with a higher factored spatiotemporal index for both lips as compared to that of the TD participant. In a story retell task, acoustic analyses of participants' responses revealed increased total utterance time in addition to increased pause time percentage in the participant with CAS versus the TD participant. During repetition of eight trochaic words, the participant with CAS presented greater mean lexical stress while the TD participant displayed stress primarily on the initial syllable. These results provide feasibility for using the given measures to differentiate speech productions of TD children from those with CAS. Additional study of the current measures on a larger scale with TD speech participants as well as in comparison with participants exhibiting other speech sound disorders is recommended.  M.S

Independent Component Analysis of Event-Related Electroencephalography During Speech and Non-Speech Discrimination: : Implications for the Sensorimotor ∆∞ Rhythm in Speech Processing

Background: The functional significance of sensorimotor integration in acoustic speech processing is unclear despite more than three decades of neuroimaging research. Constructivist theories have long speculated that listeners make predictions about articulatory goals functioning to weight sensory analysis toward expected acoustic features (e.g. analysis-by-synthesis; internal models). Direct-realist accounts posit that sensorimotor integration is achieved via a direct match between incoming acoustic cues and articulatory gestures. A method capable of favoring one account over the other requires an ongoing, high-temporal resolution measure of sensorimotor cortical activity prior to and following acoustic input. Although scalp-recorded electroencephalography (EEG) provides a measure of cortical activity on a millisecond time scale, it has low-spatial resolution due to the blurring or mixing of cortical signals on the scalp surface. Recently proposed solutions to the low-spatial resolution of EEG known as blind source separation algorithms (BSS) have made the identification of distinct cortical signals possible. The µ rhythm of the EEG is known to briefly suppress (i.e., decrease in spectral power) over the sensorimotor cortex during the performance, imagination, and observation of biological movements, suggesting that it may provide a sensitive index of sensorimotor integration during speech processing. Neuroimaging studies have traditionally investigated speech perception in two-forced choice designs in which participants discriminate between pairs of speech and nonspeech control stimuli. As such, this classical design was employed in the current dissertation work to address the following specific aims to: 1) isolate independent components with traditional EEG signatures within the dorsal sensorimotor stream network; 2) identify components with features of the sensorimotor µ rhythm and; 3) investigate changes in timefrequency activation of the µ rhythm relative to stimulus type, onset, and discriminability (i.e., perceptual performance). In light of constructivist predictions, it was hypothesized that the µ rhythm would show significant suppression for syllable stimuli prior to and following stimulus onset, with significant differences between correct discrimination trials and those discriminated at chance levels. Methods: The current study employed millisecond temporal resolution EEG to measure ongoing decreases and increases in spectral power (event-related spectral perturbations; ERSPs) prior to, during, and after the onset of acoustic speech and tone-sweep stimuli embedded in white-noise. Sixteen participants were asked to passively listen to or actively identify speech and tone signals in a two-force choice same/different discrimination task. To investigate the role of ERSPs in perceptual identification performance, high signal-to-noise ratios (SNRs) in which speech and tone identification was significantly better than chance (+4dB) and low SNRs in which performance was below chance (-6dB and -18dB) were compared to a baseline of passive noise. Independent component analysis (ICA) of the EEG was used to reduce artifact and source mixing due to volume conduction. Independent components were clustered using measure product methods and cortical source modeling, including spectra, scalp distribution, equivalent current dipole estimation (ECD), and standardized low-resolution tomography (sLORETA). Results: Data analysis revealed six component clusters consistent with a bilateral dorsal-stream sensorimotor network, including component clusters localized to the precentral and postcentral gyrus, cingulate cortex, supplemental motor area, and posterior temporal regions. Timefrequency analysis of the left and right lateralized µ component clusters revealed significant (pFDR\u3c.05) suppression in the traditional beta frequency range (13-30Hz) prior to, during, and following stimulus onset. No significant differences from baseline were found for passive listening conditions. Tone discrimination was different from passive noise in the time period following stimulus onset only. No significant differences were found for correct relative to chance tone stimuli. For both left and right lateralized clusters, early suppression (i.e., prior to stimulus onset) compared to the passive noise baseline was found for the syllable discrimination task only. Significant differences between correct trials and trials identified at chance level were found for the time period following stimulus offset for the syllable discrimination task in left lateralized cluster. Conclusions: As this is the first study to employ BSS methods to isolate components of the EEG during acoustic speech and non-speech discrimination, findings have important implications for the functional role of sensorimotor integration in speech processing. Consistent with expectations, the current study revealed component clusters associated with source models within the sensorimotor dorsal stream network. Beta suppression of the µ component clusters in both the left and right hemispheres is consistent with activity in the precentral gyrus prior to and following acoustic input. As early suppression of the µ was found prior the syllable discrimination task, the present findings favor internal model concepts of speech processing over mechanisms proposed by direct-realists. Significant differences between correct and chance syllable discrimination trials are also consistent with internal model concepts suggesting that sensorimotor integration is related to perceptual performance at the point in time when initial articulatory hypotheses are compared with acoustic input. The relatively inexpensive, noninvasive EEG methodology used in this study may have translational value in the future as a brain computer interface (BCI) approach. As deficits in sensorimotor integration are thought to underlie cognitive-communication impairments in a number of communication disorders, the development of neuromodulatory feedback approaches may provide a novel avenue for augmenting current therapeutic protocols

Factors influencing the efficacy of delayed auditory feedback in treating dysarthria associated with Parkinson\u27s disease

Parkinson\u27s disease patients exhibit a high prevalence of speech deficits including excessive speech rate, reduced intelligibility, and disfluencies. The present study examined the effects of delayed auditory feedback (DAF) as a rate control intervention for dysarthric speakers with Parkinson\u27s disease. Adverse reactions to relatively long delay intervals are commonly observed during clinical use of DAF, and seem to result from improper matching of the delayed signal. To facilitate optimal use of DAF, therefore, clinicians must provide instruction, modeling, and feedback. Clinician instruction is frequently used in speech-language therapy, but has not been evaluated during use of DAF-based interventions. Therefore, the primary purpose of the present study was to evaluate the impact of clinician instruction on the effectiveness of DAF in treating speech deficits. A related purpose was to compare the effects of different delay intervals on speech behaviors. An A-B-A-B single-subject design was utilized. The A phases consisted of a sentence reading task using DAF, while the B phases incorporated clinician instruction into the DAF protocol. During each of the 16 experimental sessions, speakers read with four different delay intervals (0 ms, 50 ms, 100 ms, and 150 ms). During the B phases, the experimenter provided verbal feedback and modeling pertaining to how precisely the speaker matched the delayed signal. Dependent variables measured were speech rate, percent intelligible syllables, and percent disfluencies. Three males with Parkinson\u27s disease and an associated dysarthria participated in the study. Results revealed that for all three speakers, DAF significantly reduced reading rate and produced significant improvements in either intelligibility (for Speaker 3) or fluency (for Speakers 1 and 2). A delay interval of 150 ms produced the greatest reductions in reading rates for all three speakers, although any of the DAF settings used was sufficient to produce significant improvements in either intelligibility or fluency. In addition, supplementing the DAF intervention with clinician instruction resulted in significantly greater gains achieved with DAF. These findings confirmed the effectiveness of various intervals of DAF in improving speech deficits in Parkinson\u27s disease speakers, particular when patients are provided with instruction and modeling from the clinician