Investigating Perceptual Subgroups in Speakers With Ataxic Dysarthria: An Auditory Free Classification Approach.

PURPOSE: Ataxic dysarthria has presented with considerable heterogeneity in the presentation of speech characteristics. Converging evidence supports the existence of subgroups, specifically related to the instability and inflexibility of motor patterns as a possible explanation of this variability. METHOD: To further examine the alignment of the speech characteristics of ataxic dysarthria with the instability/inflexibility framework, 23 graduate student listeners participated in an auditory free classification task and a guided classification task. Listeners grouped 15 speakers with ataxic dysarthria based on their judgment of the most salient perceptual characteristics during two speaking tasks: alternating motion rates (AMRs) and connected speech (one to two sentences). Listener ratings were then compared with a priori determinations of speakers who fit the instability subgroup profile and the inflexibility subgroup profile. RESULTS: Results of both the free classification and guided classification listening paradigms provided supportive evidence of subgroups, particularly for the AMR task, in the context of strong inter- and intrarater reliability. CONCLUSION: This study adds to the growing evidence of the existence of instability and inflexibility subgroups in ataxic dysarthria and serves as a proof of concept for use of the auditory free classification paradigm in dysarthria subgroup research.

The efficacy of acoustic-based articulatory phenotyping for characterizing and classifying four divergent neurodegenerative diseases using sequential motion rates.

Despite the impacts of neurodegeneration on speech function, little is known about how to comprehensively characterize the resulting speech abnormalities using a set of objective measures. Quantitative phenotyping of speech motor impairments may have important implications for identifying clinical syndromes and their underlying etiologies, monitoring disease progression over time, and improving treatment efficacy. The goal of this research was to investigate the validity and classification accuracy of comprehensive acoustic-based articulatory phenotypes in speakers with distinct neurodegenerative diseases. Articulatory phenotypes were characterized based on acoustic features that were selected to represent five components of motor performance: Coordination, Consistency, Speed, Precision, and Rate. The phenotypes were first used to characterize the articulatory abnormalities across four progressive neurologic diseases known to have divergent speech motor deficits: amyotrophic lateral sclerosis (ALS), progressive ataxia (PA), Parkinson's disease (PD), and the nonfluent variant of primary progressive aphasia and progressive apraxia of speech (nfPPA + PAOS). We then examined the efficacy of articulatory phenotyping for disease classification. Acoustic analyses were conducted on audio recordings of 217 participants (i.e., 46 ALS, 52 PA, 60 PD, 20 nfPPA + PAOS, and 39 controls) during a sequential speech task. Results revealed evidence of distinct articulatory phenotypes for the four clinical groups and that the phenotypes demonstrated strong classification accuracy for all groups except ALS. Our results highlight the phenotypic variability present across neurodegenerative diseases, which, in turn, may inform (1) the differential diagnosis of neurological diseases and (2) the development of sensitive outcome measures for monitoring disease progression or assessing treatment efficacy.

Effect of Noise on Speech Intelligibility and Perceived Listening Effort in Head and Neck Cancer.

Purpose This study (a) examined the effect of different levels of background noise on speech intelligibility and perceived listening effort in speakers with impaired and intact speech following treatment for head and neck cancer (HNC) and (b) determined the relative contribution of speech intelligibility, speaker group, and background noise to a measure of perceived listening effort. Method Ten speakers diagnosed with nasal, oral, or oropharyngeal HNC provided audio recordings of six sentences from the Sentence Intelligibility Test. All speakers were 100% intelligible in quiet: Five speakers with HNC exhibited mild speech imprecisions (speech impairment group), and five speakers with HNC demonstrated intact speech (HNC control group). Speech recordings were presented to 30 inexperienced listeners, who transcribed the sentences and rated perceived listening effort in quiet and two levels (+7 and +5 dB SNR) of background noise. Results Significant Group × Noise interactions were found for speech intelligibility and perceived listening effort. While no differences in speech intelligibility were found between the speaker groups in quiet, the results showed that, as the signal-to-noise ratio decreased, speakers with intact speech (HNC control) performed significantly better (greater intelligibility, less perceived listening effort) than those with speech imprecisions in the two noise conditions. Perceived listening effort was also shown to be associated with decreased speech intelligibility, imprecise speech, and increased background noise. Conclusions Speakers with HNC who are 100% intelligible in quiet but who exhibit some degree of imprecise speech are particularly vulnerable to the effects of increased background noise in comparison to those with intact speech. Results have implications for speech evaluations, counseling, and rehabilitation.

The Relationship Between Speech Characteristics and Motor Subtypes of Parkinson's Disease.

Purpose The aim of this study was to examine whether acoustic dysarthria characteristics align with overall motor profile in individuals with Parkinson's disease (PD). Potential speech differences between tremor-dominant and non-tremor-dominant subtypes are theoretically motivated but empirically inconclusive. Method Twenty-seven individuals with dysarthria from PD provided a contextual speech sample. Participants were grouped into non-tremor-dominant (n = 12) and tremor-dominant (n = 15) motor subtypes according to the Unified Parkinson Disease Rating Scale. Dependent speech variables included fundamental frequency range, average pause duration, cepstral peak prominence, stuttering dysfluencies, and maze dysfluencies. Results There were no significant differences between the speech of the tremor-dominant and non-tremor-dominant groups. High within-group variability existed across parameters and motor subtypes. Conclusion Speech characteristics across the areas of phonation, prosody, and fluency did not differ appreciably between PD motor subtypes.

Cognitive Rehabilitation for Individuals With Parkinson's Disease: Developing and Piloting an External Aids Treatment Program.

Purpose Cognitive deficits are common in Parkinson's disease (PD) and can have a detrimental effect on daily activities. To date, most cognitive treatments have had an impairment-based focus with primary outcome measures of formal neuropsychological test scores. Few, if any, studies have focused on functional improvement or patient-centered goals. Method Three individuals with idiopathic PD participated in an 8-week pilot treatment program to train for the use of compensatory external aids to achieve personalized goals. Goal attainment scaling was the primary outcome measure, which was independently judged by multiple raters at baseline, postintervention, and 1 month posttreatment and analyzed via T-score analysis. Descriptive measures, including self-report and spouse-report rating scales of cognitive functioning, were employed. Results All 3 participants improved in the majority of their laboratory and home goals posttreatment, as measured by goal attainment scaling, and maintained gains for the majority of goals 1 month posttreatment. Conclusions This is the 1st known study to implement an external aids treatment program with patient-centered goals for individuals with cognitive deficits from PD. Positive outcomes were likely influenced by 3 factors: (a) a theoretically motivated focus on external aids; (b) a well-documented, systematic approach to instruction; and (c) the personalization of goals. Supplemental Material https://doi.org/10.23641/asha.10093493.

Dysarthria Profiles in Adults With Hereditary Ataxia.

Purpose This preliminary study examined whether speech profiles exist for adults with hereditary ataxia based on 2 competing frameworks: a pattern of instability/inflexibility or a pattern of differential subsystem involvement. Method Four dysarthria experts rated the speech samples of 8 adults with dysarthria from hereditary ataxia using visual analog scales and presence/severity rating scales of speech characteristics. Speaking tasks included diadochokinetics, sustained phonation, and a monologue. Results Speech profiles aligned with the instability/inflexibility framework, with the pattern of instability being the most common. Speech profiles did not emerge for the majority of speakers using the differential subsystem framework. Conclusions The findings extend previous research on pure ataxic dysarthria and suggest a possible framework for understanding the speech heterogeneity associated with the ataxias. The predominance of the instability profile is consistent with the notion of impaired feedforward control in speakers with cerebellar disruption.

Investigation of Feedback Schedules on Speech Motor Learning in Older Adults.

BACKGROUND: The principles of motor learning (PML) emerged from studies of limb motor skills in healthy, young adults. The applicability of these principles to speech motor learning, and to older adults, is uncertain. AIMS: The purpose of this study was to examine one PML, feedback frequency, and its effect on retention and generalization of a novel speech and comparable tracing task. METHODS: Sixty older adults completed a speech motor learning task requiring the production of a novel phrase at speaking rates 2 times and 3 times slower than habitual rate. Participants also completed a limb motor learning task requiring the tracing of a sine wave 2x and 3x slower than habitual rate. Participants were randomly assigned to receive feedback every trial, every 5th trial, or every 10th trial. Mean absolute error was measured to examine immediate generalization, delayed generalization, and 2-day retention. FINDINGS: Results suggested that feedback frequency did not have an effect on the retention and generalization of the speech or manual task, supporting the small but growing literature highlighting the constraints of generalizing the PML to other modalities and populations.

The Relationship Between Non-Orthographic Language Abilities and Reading Performance in Chronic Aphasia: An Exploration of the Primary Systems Hypothesis.

Purpose: This study investigated the relationship between non-orthographic language abilities and reading in order to examine assumptions of the primary systems hypothesis and further our understanding of language processing poststroke. Method: Performance on non-orthographic semantic, phonologic, and syntactic tasks, as well as oral reading and reading comprehension tasks, was assessed in 43 individuals with aphasia. Correlation and regression analyses were conducted to determine the relationship between these measures. In addition, analyses of variance examined differences within and between reading groups (within normal limits, phonological, deep, or global alexia). Results: Results showed that non-orthographic language abilities were significantly related to reading abilities. Semantics was most predictive of regular and irregular word reading, whereas phonology was most predictive of pseudohomophone and nonword reading. Written word and paragraph comprehension were primarily supported by semantics, whereas written sentence comprehension was related to semantic, phonologic, and syntactic performance. Finally, severity of alexia was found to reflect severity of semantic and phonologic impairment. Conclusions: Findings support the primary systems view of language by showing that non-orthographic language abilities and reading abilities are closely linked. This preliminary work requires replication and extension; however, current results highlight the importance of routine, integrated assessment and treatment of spoken and written language in aphasia. Supplemental Material: https://doi.org/10.23641/asha.7403963.

Links Between Short-Term Memory and Word Retrieval in Aphasia.

Purpose: This study explored the relationship between anomia and verbal short-term memory (STM) in the context of an interactive activation language processing model. Method: Twenty-four individuals with aphasia and reduced STM spans (i.e., impaired immediate serial recall of words) completed a picture-naming task and a word pair repetition task (a measure of verbal STM). Correlations between verbal STM and word retrieval errors made on the picture-naming task were examined. Results: A significant positive correlation between naming accuracy and verbal span length was found. More intricate verbal STM analyses examined the relationship between picture-naming error types (i.e., semantic vs. phonological) and 2 measures of verbal STM: (a) location of errors on the word pair repetition task and (b) imageability and frequency effects on the word pair repetition task. Results indicated that, as phonological word retrieval errors (relative to semantic) increase, bias toward correct repetition of high-imageability words increases. Conclusions: Results suggest that word retrieval and verbal STM tasks likely rely on a partially shared temporary linguistic activation process.

Dysarthria following Stroke.

Dysarthria is a common consequence of stroke and can have a detrimental influence on communication and quality of life. Speech-language pathologists (SLPs) play an important role in the evaluation and rehabilitation of stroke survivors who present with dysarthria. An understanding of the physiologic reason behind the altered speech characteristics, such as weakness or incoordination, can facilitate differential diagnosis, guide evaluation strategies, and influence treatment approaches. An initial comprehensive speech evaluation is comprised of examination of the speech mechanism, screening of speech subsystems, perceptual assessment, and intelligibility measurement. Management strategies focus on optimizing communication through compensatory strategies as well as providing physiologic support. The SLP is also responsible for educating family and staff regarding strategies that can facilitate communication.

Internally Versus Externally Cued Speech in Parkinson's Disease and Cerebellar Disease.

PURPOSE: The purpose of this study was to examine the effects of an internally versus externally cued speech task on perceived understandability and naturalness in speakers with Parkinson's disease (PD) and cerebellar disease (CD). METHOD: Sentences extracted from a covertly recorded conversation (internally cued) were compared to the same sentences read aloud (externally cued) by speakers with PD and a clinical comparison group of speakers with CD. Experienced listeners rated the speech samples using a visual analog scale for the perceptual dimensions of understandability and naturalness. RESULTS: Results suggest that experienced listeners rated the speech of participants with PD as significantly more natural and more understandable during the reading condition. Participants with CD were also rated as significantly more understandable during the reading condition, but ratings of naturalness did not differ between conversation and reading. CONCLUSIONS: Speech tasks can have a pronounced impact on perceived speech patterns. For individuals with PD, both understandability and naturalness can improve during reading tasks versus conversational tasks. The speech benefits from reading may be attributed to several mechanisms, including possible improvement from an externally cued speech task. These findings have implications for speech task selection in evaluating individuals with dysarthria.

The Nature of Error Consistency in Individuals With Acquired Apraxia of Speech and Aphasia.

PURPOSE: The primary characteristics used to define acquired apraxia of speech (AOS) have evolved to better reflect a disorder of motor planning/programming. However, there is debate regarding the feature of relatively consistent error location and type. METHOD: Ten individuals with acquired AOS and aphasia and 11 individuals with aphasia without AOS participated in this study. In the context of a 2-group experimental design, error consistency was examined via 5 repetitions of 30 multisyllabic words. The influence of error rate, severity of impairment, and stimulus presentation condition (blocked vs. random) on error consistency was also explored, as well as between-groups differences in the types of errors produced. RESULTS: Groups performed similarly on consistency of error location; however, adults with AOS demonstrated greater variability of error type in a blocked presentation condition only. Stimulus presentation condition, error rate, and severity of impairment did not influence error consistency in either group. Groups differed in the production of phonetic errors (e.g., sound distortions) but not phonemic errors. CONCLUSIONS: Overall, findings do not support relatively consistent errors as a differentiating characteristic of AOS.

Addressing Communicative Participation in Treatment Planning for Adults: A Survey of U.S. Speech-Language Pathologists.

PURPOSE: In speech-language pathology, there is increasing attention on participation-focused interventions to optimize participation in valued life roles. The purpose of this study was to investigate how speech-language pathologists (SLPs) in the United States address life participation in therapy programs, as well as their opinions regarding barriers and facilitators to participation-focused intervention. METHOD: An online questionnaire presented case scenarios for aphasia, dysarthria, and laryngectomy to 66 SLPs who have worked with adults. SLPs were asked to write goals and describe therapy activities for the scenarios. The final section of the questionnaire was an open-ended question regarding barriers and facilitators to participation-focused intervention. RESULTS: Many SLPs addressed participation in their rationales for therapy; 50% of goals had a participation-focused rationale. However, the goals, activities, and outcomes measures typically focused more on impairment and skill performance. Only 8% of goals specifically referenced participation. Although many SLPs stated that participation-focused intervention is important, they identified many barriers to implementation including time and productivity constraints, limits of clinical settings, and documentation challenges. CONCLUSIONS: There is potential for gaps between SLPs' participation-focused rationale for therapy and activities or outcomes measures that often do not include participation elements. SLPs are interested in participation-focused treatment resources.

Perceptual ratings of subgroups of ataxic dysarthria.

BACKGROUND: The speech characteristics of ataxic dysarthria are known to be quite diverse. The varied presentation of this dysarthria challenges researchers and clinicians alike, and brings into question whether it is a single entity. While the possibility of subtypes of ataxic dysarthria has been suggested, the nature of these putative groups remains unclear. AIMS: The purpose of this pilot study was to determine if perceptual speech characteristics would align with a pattern of unusual variability or unusual consistency across speech subsystems and speaking tasks. METHODS & PROCEDURES: A framework of speech characteristics was created from the existing literature that clustered speech attributes according to notions of instability (unusual variability) or inflexibility (unusual consistency). These speech features were used to develop a perceptual rating form. Ten experienced speech-language pathologists listened to pre-recorded, exemplary samples of 10 speakers with ataxic dysarthria and rated the perceptual speech features. OUTCOMES & RESULTS: Results suggested that five speakers fit the pattern of instability, one speaker aligned with inflexibility and four speakers had a mixed presentation. Intra-rater reliability was satisfactory. CONCLUSIONS & IMPLICATIONS: This study adds to the sparse, yet growing, literature to support the existence of subgroups in ataxic dysarthria. The more frequent occurrence of the instability profile is consistent with primary disruption to the timing function of the cerebellar circuit. Identification of subgroups has important clinical and research implications and further research is warranted.

The impact of dose on naming accuracy with persons with aphasia.

BACKGROUND: Although aphasia rehabilitation has been shown to be efficacious, many questions remain regarding how best to deliver treatment to maximize functional gains for persons with aphasia. Treatment delivery variables, such as intensity and dosage, are likely to influence both behavioral and structural changes during anomia treatment. While numerous protocols have concluded that treatment intensity positively impacts functional outcomes, few studies to date have examined the role that dose plays in patient outcomes for anomia treatment. AIMS: This study sought to investigate how manipulating dose of repeated confrontation naming within sessions influences naming in persons with aphasia. Repeated practice of confrontation naming, without feedback, was hypothesized to improve trained but not untrained words, to be persistent after withdrawal, and to be sensitive to the number of trials (i.e., dose) within sessions. METHODS AND PROCEDURES: A single-subject ABA design with replication across seven participants with aphasia was used to investigate the influence of repeated confrontation naming attempts on the acquisition and maintenance of trained pictures relative to untrained pictures. Training involved repeated attempts to name pictures, along with repeated exposure to pictures of objects (nouns) and their names, without feedback. The primary independent variable was within session dose; the dependent variable was naming accuracy. OUTCOMES AND RESULTS: Naming accuracy improved for all participants for trained pictures across both acquisition and maintenance phases per visual inspection; such positive effects were not observed for untrained pictures. Effect size calculations indicate that three of seven participants demonstrated considerable change for trained items, while one of seven participants demonstrated meaningful change for untrained items. The high-dose condition elicited small effect sizes for one participant, and large effect sizes for two of seven participants, while the low-dose condition elicited small and medium effect sizes for two of seven participants. CONCLUSIONS: Participants across a variety of aphasia severity levels responded positively to two doses of repeated confrontation naming practice, without feedback, across phases of this naming protocol. Results are in line with principles of neuroplasticity and demonstrate that repeated practice, without feedback, can produce significant and persistent changes in naming ability for some persons with aphasia.

Intentional and Reactive Inhibition During Spoken-Word Stroop Task Performance in People With Aphasia.

PURPOSE: The integrity of selective attention in people with aphasia (PWA) is currently unknown. Selective attention is essential for everyday communication, and inhibition is an important part of selective attention. This study explored components of inhibition-both intentional and reactive inhibition-during spoken-word production in PWA and in controls who were neurologically healthy (HC). Intentional inhibition is the ability to suppress a response to interference, and reactive inhibition is the delayed reactivation of a previously suppressed item. METHOD: Nineteen PWA and 20 age- and education-matched HC participated in a Stroop spoken-word production task. This task allowed the examination of intentional and reactive inhibition by evoking and comparing interference, facilitation, and negative priming effects in different contexts. RESULTS: Although both groups demonstrated intentional inhibition, PWA demonstrated significantly more interference effects. PWA demonstrated no significant facilitation effects. HC demonstrated significant reverse facilitation effects. Neither group showed significant evidence of reactive inhibition, though both groups showed similar individual variability. CONCLUSIONS: These results underscore the challenge interference presents for PWA during spoken-word production, indicating diminished intentional inhibition. Although reactive inhibition was not different between PWA and HC, PWA showed difficulty integrating and adapting to contextual information during language tasks.

Sequence complexity effects on speech production in healthy speakers and speakers with hypokinetic or ataxic dysarthria.

The present study investigated the effects of sequence complexity, defined in terms of phonemic similarity and phonotoactic probability, on the timing and accuracy of serial ordering for speech production in healthy speakers and speakers with either hypokinetic or ataxic dysarthria. Sequences were comprised of strings of consonant-vowel (CV) syllables with each syllable containing the same vowel, /a/, paired with a different consonant. High complexity sequences contained phonemically similar consonants, and sounds and syllables that had low phonotactic probabilities; low complexity sequences contained phonemically dissimilar consonants and high probability sounds and syllables. Sequence complexity effects were evaluated by analyzing speech error rates and within-syllable vowel and pause durations. This analysis revealed that speech error rates were significantly higher and speech duration measures were significantly longer during production of high complexity sequences than during production of low complexity sequences. Although speakers with dysarthria produced longer overall speech durations than healthy speakers, the effects of sequence complexity on error rates and speech durations were comparable across all groups. These findings indicate that the duration and accuracy of processes for selecting items in a speech sequence is influenced by their phonemic similarity and/or phonotactic probability. Moreover, this robust complexity effect is present even in speakers with damage to subcortical circuits involved in serial control for speech.

Speech serial control in healthy speakers and speakers with hypokinetic or ataxic dysarthria: effects of sequence length and practice.

The current study investigated the processes responsible for selection of sounds and syllables during production of speech sequences in 10 adults with hypokinetic dysarthria from Parkinson's disease, five adults with ataxic dysarthria, and 14 healthy control speakers. Speech production data from a choice reaction time task were analyzed to evaluate the effects of sequence length and practice on speech sound sequencing. Speakers produced sequences that were between one and five syllables in length over five experimental runs of 60 trials each. In contrast to the healthy speakers, speakers with hypokinetic dysarthria demonstrated exaggerated sequence length effects for both inter-syllable intervals (ISIs) and speech error rates. Conversely, speakers with ataxic dysarthria failed to demonstrate a sequence length effect on ISIs and were also the only group that did not exhibit practice-related changes in ISIs and speech error rates over the five experimental runs. The exaggerated sequence length effects in the hypokinetic speakers with Parkinson's disease are consistent with an impairment of action selection during speech sequence production. The absent length effects observed in the speakers with ataxic dysarthria is consistent with previous findings that indicate a limited capacity to buffer speech sequences in advance of their execution. In addition, the lack of practice effects in these speakers suggests that learning-related improvements in the production rate and accuracy of speech sequences involves processing by structures of the cerebellum. Together, the current findings inform models of serial control for speech in healthy speakers and support the notion that sequencing deficits contribute to speech symptoms in speakers with hypokinetic or ataxic dysarthria. In addition, these findings indicate that speech sequencing is differentially impaired in hypokinetic and ataxic dysarthria.

Speech motor program maintenance, but not switching, is enhanced by left-hemispheric deep brain stimulation in Parkinson's disease.

Speech reaction time (SRT) was measured in a response priming protocol in 12 participants with Parkinson's disease (PD) and hypokinetic dysarthria "on" and "off" left-hemispheric deep brain stimulation (DBS). Speech preparation was measured during speech motor programming in two randomly ordered speech conditions: speech maintenance and switching. Double blind testing was completed in participants with DBS of globus pallidus pars interna (GPi) (n = 5) or subthalamic nucleus (STN) (n = 7). SRT was significantly faster in the maintenance vs switch task, regardless of DBS state. SRT was faster in the speech maintenance task "on" stimulation, while there was no difference in speech switching "on" and "off" DBS. These data suggest that left-hemispheric DBS may have differential effects on aspects of speech preparation in PD. It is hypothesized that speech maintenance improvements may result from DBS-induced cortical enhancements, while the lack of difference in switching may be related to inhibition deficits mediated by the right-hemisphere. Alternatively, DBS may have little influence on the higher level motor processes (i.e., motor planning) which it is believed the switch task engaged to a greater extent than the maintenance task.

The effect of feedback schedule manipulation on speech priming patterns and reaction time.

Speech priming tasks are frequently used to delineate stages in the speech process such as lexical retrieval and motor programming. These tasks, often measured in reaction time (RT), require fast and accurate responses, reflecting maximized participant performance, to result in robust priming effects. Encouraging speed and accuracy in responding can take many forms, including verbal instructions and feedback, and often involves visually displayed RT feedback. However, it is uncertain how manipulation of the schedule of this RT feedback influences speech RT speed and, ultimately, the priming effect. This experiment examined the effect of visually presented RT feedback schedules on priming patterns in 20 older healthy adults. Results suggested that feedback schedule manipulation had a differential effect on reaction time, depending on the interstimulus interval between the prime and the target, but no effect on response priming patterns.