Reliability and stability of the metrical stress effect on segmental production accuracy in persons with apraxia of speech.

BACKGROUND: Acquired apraxia of speech (AOS) involves speech-production deficits on both the segmental and suprasegmental levels. Recent research has identified a non-linear interaction between the metrical structure of bisyllabic words and word-production accuracy in German speakers with AOS, with trochaic words (strong-weak stress) being resistant to errors compared with iambic words (weak-strong). AIMS: To replicate previous findings in English speakers with AOS, to measure the test-retest reliability of the effect, and to examine the potential impact of different methods of word scoring. METHODS & PROCEDURES: Speech samples were collected from 27 speakers with AOS and aphasia. Participants were at least 12 months post-stroke or penetrating brain injury, and represented a large range of AOS and aphasia severities. Productions were elicited via verbal model. Sampling was conducted on three separate occasions: the initial data-collection session and then repeated samplings at 1- and 4-week intervals. Bisyllabic words with a CVCVC segmental structure were selected. The list was divided into sublists representing differing lexical stress patterns: A list of 42 trochees, and one of 37 iambs. All speech samples were phonetically transcribed and then aligned with canonical transcriptions via an edit distance algorithm that followed transcription alignment principles. Phonetic-level errors (distortions) were penalized less severely than phonemic-level errors. Per cent consonants correct and whole-word accuracy were also examined. Trochee and iamb lists were analysed separately. OUTCOMES & RESULTS: Paired samples t-tests indicated that the modified edit distance was significantly lower for the trochee lists than for the iamb lists. There was a lack of a significant effect of time on the absolute difference between modified edit distance for both lists. Intraclass coefficients suggested the list and procedures used are appropriate as an outcome measure for group research. CONCLUSIONS & IMPLICATIONS: The results suggest that in English, as in German, the trochaic structure is more resistant to segmental errors in persons with AOS and aphasia, providing replication of the findings of Aichert et al. in 2016. Further, this effect is stable over repeated sampling occasions. Implications for clinical management of AOS include possible ways to scaffold item difficulty and potentially improve stimulus generalization.

Contextual Constraint Treatment for coarse coding deficit in adults with right hemisphere brain damage: generalisation to narrative discourse comprehension.

Coarse coding is the activation of broad semantic fields that can include multiple word meanings and a variety of features, including those peripheral to a word's core meaning. It is a partially domain-general process related to general discourse comprehension and contributes to both literal and non-literal language processing. Adults with damage to the right cerebral hemisphere (RHD) and a coarse coding deficit are particularly slow to activate features of words that are relatively distant or peripheral. This manuscript reports a pre-efficacy study of Contextual Constraint Treatment (CCT), a novel, implicit treatment designed to increase the efficiency of coarse coding with the goal of improving narrative comprehension and other language performance that relies on coarse coding. Participants were four adults with RHD. The study used a single-subject controlled experimental design across subjects and behaviours. The treatment involved pre-stimulation, using a hierarchy of strong and moderately biased contexts, to prime the intended distantly related features of critical stimulus words. Three of the four participants exhibited gains in auditory narrative discourse comprehension, the primary outcome measure. All participants exhibited generalisation to untreated items. No strong generalisation to processing non-literal language was evident. The results indicate that CCT yields both improved efficiency of the coarse coding process and generalisation to narrative comprehension.

Stability Over Time of Word Syllable Duration for Speakers With Acquired Apraxia of Speech.

PURPOSE: Neurogenic speech and language disorders-such as acquired apraxia of speech (AOS) and aphasia with phonemic paraphasia (APP)-are often misdiagnosed due to similarities in clinical presentation. Word syllable duration (WSD)-a measure of average syllable length in multisyllabic words-serves as a proxy for speech rate, which is an important and arguably more objective clinical characteristic of AOS and APP. This study reports stability of WSD over time for speakers with AOS (and aphasia). METHOD: Twenty-nine participants with AOS and aphasia (11 women and 18 men, Mage = 53.5 years, SD = 13.3) repeated 30 multisyllabic words (of three-, four-, and five-syllable lengths) on three occasions across 4 weeks. WSDs were calculated for each word and then averaged across each list (i.e., word length), as well as across combined lists (i.e., all 30 words) to yield four WSDs for each participant at each time point. Stability over time was calculated using Friedman's test for the group and using Spearman's rho for the individual level. Effects of time and word length were examined using robust mixed-effects linear regression. RESULTS: Friedman's tests and correlations indicated no significant difference in WSDs across sampling occasions for each word length separately or combined. WSD correlated positively with AOS severity and negatively with intelligibility but was not correlated with aphasia severity. Regression analyses confirmed WSD to be stable over time, while WSD calculated from only five tokens (i.e., WSD-5) was less stable over time. CONCLUSIONS: Results indicate that WSD can be a stable measure over time, at the individual and group level, providing support for its use in diagnosis and/or as an outcome measure, both clinically and for research. In general, WSD outperformed WSD-5, suggesting that it may be better to calculate WSD from more than five tokens. Stability of WSD in other populations and suitability for differential diagnosis need to be determined. Currently, differentiating disorders by speaking rate, alone, is not recommended. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25438735.

Self- and surrogate-reported communication functioning in aphasia.

PURPOSE: To evaluate the dimensionality and measurement invariance of the aphasia communication outcome measure (ACOM), a self- and surrogate-reported measure of communicative functioning in aphasia. METHODS: Responses to a large pool of items describing communication activities were collected from 133 community-dwelling persons with aphasia of ≥ 1 month post-onset and their associated surrogate respondents. These responses were evaluated using confirmatory and exploratory factor analysis. Chi-square difference tests of nested factor models were used to evaluate patient-surrogate measurement invariance and the equality of factor score means and variances. Association and agreement between self- and surrogate reports were examined using correlation and scatterplots of pairwise patient-surrogate differences. RESULTS: Three single-factor scales (Talking, Comprehension, and Writing) approximating patient-surrogate measurement invariance were identified. The variance of patient-reported scores on the Talking and Writing scales was higher than surrogate-reported variances on these scales. Correlations between self- and surrogate reports were moderate-to-strong, but there were significant disagreements in a substantial number of individual cases. CONCLUSIONS: Despite minimal bias and relatively strong association, surrogate reports of communicative functioning in aphasia are not reliable substitutes for self-reports by persons with aphasia. Furthermore, although measurement invariance is necessary for direct comparison of self- and surrogate reports, the costs of obtaining invariance in terms of scale reliability and content validity may be substantial. Development of non-invariant self- and surrogate report scales may be preferable for some applications.

Pattern-Based Target Selection for Treatment of Irregular Past Tense: A Single-Case Experimental Design for Children With Developmental Language Disorder.

PURPOSE: Many children with developmental language disorder (DLD) demonstrate difficulty inflecting irregular past tense verbs. We evaluated using phonological-based patterns (i.e., schemas) to select targets for treatment of irregular verb inflection for children with DLD. We hypothesized this approach would result in acquisition of treated verbs, generalization to untreated verbs within the same phonological schema, and increased use of correct irregular verbs in naturalistic contexts. METHOD: Treatment was provided to three 7-year-old participants with DLD in the context of multiple baseline designs across behaviors and participants. Phonological schemas included vowel change, final alveolar, and dual change irregular verbs. Treatment was provided using established therapeutic approaches, including narrative generation, sentence imitation, and naturalistic play activities. Acquisition of treated and untreated targets was assessed at the beginning of sessions, and use of verbs in naturalistic contexts was observed throughout treatment sessions. RESULTS: Positive acquisition effects were noted for two of three participants. Generalization to untreated items occurred within and across treatment sets for two participants, whereas increases in accurate irregular verb production in naturalistic contexts were not observed. CONCLUSIONS: Outcomes demonstrated support for a pattern-based approach to target selection for treatment of irregular past tense verbs. One participant, who demonstrated general difficulty with the probe and treatment tasks, showed no treatment effect, suggesting that the treatment may be effective for some children with DLD. Further research is warranted to determine what factors might have influenced these variable outcomes across participants. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23671500.

The Impact of Telehealth on the Efficacy of Sound Production Treatment.

PURPOSE: This investigation was designed to systematically examine the acquisition, maintenance, and response generalization effects of Sound Production Treatment (SPT) delivered via telehealth in comparison to existing in-person outcomes for SPT. METHOD: A multiple-baseline design across behaviors and participants was used with two individuals with chronic apraxia of speech (AOS) and aphasia. Accuracy of target speech sounds in treated and untreated words within phrases served as the dependent variable. RESULTS: Both participants demonstrated positive gains for treatment and generalization items. Participant 1 demonstrated gains for both sets of treatment items with the application of treatment, but production accuracy at 2 and 6 weeks posttreatment was inconsistent. Participant 2 demonstrated large gains for both sets of treatment items with good maintenance at 2 and 6 weeks posttreatment. Effect sizes for both participants were similar to the traditional (in-person) SPT effect size benchmarks. CONCLUSIONS: The positive outcomes from this study indicate that individuals with AOS can benefit from SPT delivered via telehealth. These findings warrant further research examining the effects of SPT through telehealth and should include individuals with AOS with varying severity. This investigation serves as the first telehealth study to systematically examine treatment outcomes for SPT.

The Outcomes of Remote Administration of Combined Aphasia and Apraxia of Speech Treatment: A Single-Subject Experimental Design Study.

PURPOSE: This study was designed to examine the outcomes of Combined Aphasia and Apraxia of Speech Treatment (CAAST) administered remotely in terms of acquisition and generalization effects and to compare these effects to previous in-person CAAST studies and Response Elaboration Training (RET)/Modified-Response Elaboration Training (M-RET) benchmarks. METHOD: Multiple probe designs across participants and behaviors were employed with three speakers with chronic aphasia and apraxia of speech. Correct information units (CIUs) were the primary outcome measure to measure changes in language production. Percent consonants correct (PCC) was used as the secondary outcome measure to evaluate changes in speech sound accuracy. Production of CIUs was compared with existing benchmarks from Bunker et al.'s (2019) meta-analysis of previous RET/M-RET studies. In addition, both CIUs and PCC were compared with the most recent CAAST in-person studies. RESULTS: All participants demonstrated substantial increases in CIUs for treated and untreated picture sets, comparable to outcomes of in-person CAAST administration. These language changes were maintained at posttreatment intervals for all participants. PCC also improved for all participants, with gains in articulatory accuracy being maintained posttreatment. CONCLUSIONS: Improvements in CIU production and PCC for all three participants were in keeping with results from Wambaugh et al. (2017). These findings provide additional support for the efficacy of CAAST and indicate that remote administration may be a viable alternative to in-person application. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23418635.

A Comparison of Sound Production Treatment and Metrical Pacing Therapy for Apraxia of Speech: A Single-Case Experimental Design.

PURPOSE: The purpose of this investigation was to compare the effects of two specific treatment protocols for acquired apraxia of speech (AOS): Sound Production Treatment (SPT) and Metrical Pacing Therapy (MPT), and to examine changes in communicative participation. METHOD: Four speakers with chronic AOS and aphasia were each administered SPT and MPT in a replicated crossover design (ABACA/ACABA) with nonconcurrent multiple baselines across participants and behaviors. Treatment outcomes were compared with respect to whole word correctness (WWC) for treated and untreated multisyllabic word targets. Speech intelligibility was assessed using the Chapel Hill Multilingual Intelligibility Test, and communicative participation was measured using the Communicative Participation Item Bank at baseline, washout, and follow-up phases. RESULTS: Three of the four participants experienced statistically significant improvements in WWC with SPT, and three of the four participants with MPT. Based on a priori criteria, three participants demonstrated relatively greater benefit from SPT and one participant demonstrated relatively greater benefit from MPT. There were measurable improvements in intelligibility following SPT for three of the four participants. Only one participant in this investigation reported a significant change in communicative participation, and only following MPT. CONCLUSIONS: This study demonstrated that individuals in the chronic stages of AOS can benefit from both SPT and MPT, corroborating prior research on articulatory kinematic and rate and/or rhythm control treatment approaches. It contributes a comparison of two protocols for AOS with respect to whole word targets, intelligibility, and individual self-report of communicative participation changes. More participants showed a relative advantage of SPT over MPT. One individual reported communicative participation improvement after MPT. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23971929.

Reproducibility in Small-N Treatment Research: A Tutorial Using Examples From Aphasiology.

PURPOSE: Small-N studies are the dominant study design supporting evidence-based interventions in communication science and disorders, including treatments for aphasia and related disorders. However, there is little guidance for conducting reproducible analyses or selecting appropriate effect sizes in small-N studies, which has implications for scientific review, rigor, and replication. This tutorial aims to (a) demonstrate how to conduct reproducible analyses using effect sizes common to research in aphasia and related disorders and (b) provide a conceptual discussion to improve the reader's understanding of these effect sizes. METHOD: We provide a tutorial on reproducible analyses of small-N designs in the statistical programming language R using published data from Wambaugh et al. (2017). In addition, we discuss the strengths, weaknesses, reporting requirements, and impact of experimental design decisions on effect sizes common to this body of research. RESULTS: Reproducible code demonstrates implementation and comparison of within-case standardized mean difference, proportion of maximal gain, tau-U, and frequentist and Bayesian mixed-effects models. Data, code, and an interactive web application are available as a resource for researchers, clinicians, and students. CONCLUSIONS: Pursuing reproducible research is key to promoting transparency in small-N treatment research. Researchers and clinicians must understand the properties of common effect size measures to make informed decisions in order to select ideal effect size measures and act as informed consumers of small-N studies. Together, a commitment to reproducibility and a keen understanding of effect sizes can improve the scientific rigor and synthesis of the evidence supporting clinical services in aphasiology and in communication sciences and disorders more broadly. Supplemental Material and Open Science Form: https://doi.org/10.23641/asha.21699476.

Stability of Speech Intelligibility Measures Over Repeated Sampling Times in Speakers With Acquired Apraxia of Speech.

Purpose The purpose of this investigation was to measure the test-retest stability of single-word intelligibility in a group of 28 speakers with chronic apraxia of speech and aphasia. Method The Assessment of Intelligibility of Dysarthric Speech was administered twice to each participant, with samples separated by 1 week. Scoring of recorded samples was completed independently by three expert listeners using transcription and multiple-choice scoring formats. Results Percent intelligible words was very similar for the group over the two sampling times for both scoring formats (i.e., within 1.5%), with no statistically significant differences found between times. Statistically significant, very strong, positive correlations were found between sampling times for intelligibility scores. Transcription and multiple-choice scores were strongly, positively correlated, with multiple-choice scores being statistically higher. There was a statistically significant difference between mean transcription and multiple-choice scores for the group at Time 1 and Time 2. Individual performance was similar to group performance for the majority of participants. Conclusions These findings indicate that single-word intelligibility measures are stable over repeated sampling occasions. Stability was evident for transcription and multiple-choice scoring methods. Supplemental Material https://doi.org/10.23641/asha.14226737.

Sound Production Treatment for Acquired Apraxia of Speech: An Examination of Dosage in Relation to Probe Performance.

Purpose This study was designed to examine the association of dosage and effects of Sound Production Treatment (SPT) for acquired apraxia of speech. Method Treatment logs and probe data from 20 speakers with apraxia of speech and aphasia were submitted to a retrospective analysis. The number of treatment sessions and teaching episodes was examined relative to (a) change in articulation accuracy above baseline performance, (b) mastery of production, and (c) maintenance. The impact of practice schedule (SPT-Blocked vs. SPT-Random) was also examined. Results The average number of treatment sessions conducted prior to change was 5.4 for SPT-Blocked and 3.9 for SPT-Random. The mean number of teaching episodes preceding change was 334 for SPT-Blocked and 179 for SPT-Random. Mastery occurred within an average of 13.7 sessions (1,252 teaching episodes) and 12.4 sessions (1,082 teaching episodes) for SPT-Blocked and SPT-Random, respectively. Comparisons of dosage metric values across practice schedules did not reveal substantial differences. Significant negative correlations were found between follow-up probe performance and the dosage metrics. Conclusions Only a few treatment sessions were needed to achieve initial positive changes in articulation, with mastery occurring within 12-14 sessions for the majority of participants. Earlier occurrence of change or mastery was associated with better follow-up performance. Supplemental Material https://doi.org/10.23641/asha.12592190.

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.

An Aphasia Treatment for Verbs With Low Concreteness: A Pilot Study.

Purpose Verbs with low concreteness are frequent in discourse samples but rarely targeted in aphasia treatments for verbs. These verbs are an important part of functional communication, and recent studies have called for more research regarding aphasia and treatment stimuli with low concreteness. The aim of this study was to pilot the use of verbs with low concreteness in a novel sentence production intervention with persons with aphasia. Method The study took the form of a single-case experimental design with multiple baselines across behaviors and across participants. Three persons with chronic nonfluent aphasia and apraxia of speech participated in the study. Each participant received treatment designed to increase the semantic networks of verbs with high frequency and low concreteness. Sentence production was closely examined over the course of treatment for treated and untreated verbs of varying concreteness levels. Additional measures of language and cognitive functioning were also taken before and after treatment. Results Results indicated improved sentence production with target verbs attributable to the treatment in the 1st phase of 2 phases for 2 of the 3 participants. The increases corresponded with the application of treatment, despite the difference in number of baseline sessions for the participants. Where there were treatment effects, there was also considerable generalization to untreated sets of items during the 1st treatment phase. Word retrieval also improved for 2 participants. Conclusions The results suggest that the novel treatment may improve sentence production and word retrieval in persons with aphasia, even when using target verbs with low concreteness ratings. Future research is warranted into the use of low concreteness verbs. Supplemental Material https://doi.org/10.23641/asha.10870958.

Further Study of the Effects of Treatment Intensity on Outcomes of Sound Production Treatment for Acquired Apraxia of Speech: Does Dose Frequency Matter?

Purpose The aim of this study was to examine the effects of dose frequency, an aspect of treatment intensity, on articulation outcomes of sound production treatment (SPT). Method Twelve speakers with apraxia of speech and aphasia received SPT administered with an intense dose frequency and a nonintense/traditional dose frequency (SPT-T). Each participant received both treatment intensities in the context of multiple baseline designs across behaviors. SPT-Intense was provided for 3 hourly sessions per day/3 days per week; and SPT-T for 1 hour-long session per day/3 days per week. Twenty-seven treatment sessions were completed with each phase of treatment. Articulation accuracy was measured in probes of production of treated and untreated words. Results All participants achieved improved articulation of treated words with both intensities; there were no notable differences in magnitude of improvement associated with dose frequency. Positive response generalization to untrained words was found in 21 of 24 treatment applications; the cases of negligible response generalization occurred with SPT-T words. Conclusions Dose frequency (and corresponding total intervention duration) did not appear to impact treatment response for treated items. Disparate response generalization findings for 3 participants in the current study may relate to participant characteristics such as apraxia of speech severity and/or stimuli factors.

Sound Distortion Errors in Aphasia With Apraxia of Speech.

Purpose Loosely defined diagnostic criteria for acquired apraxia of speech (AOS) limit clinicians' ability to diagnose the disorder validly and reliably. The purpose of this study was to contribute to the development of more precise diagnostic guidelines by characterizing the frequency and quality of sound distortion errors in speakers with clinically diagnosed AOS. Method Audio-recorded motor speech evaluations from 24 speakers with AOS and aphasia were analyzed by trained listeners using a narrow phonetic transcription protocol that included 12 distortion categories. We calculated percentage of segments transcribed with phonemic error, distortion error, and a combination of phonemic and distortion error. Results Distortion frequency varied substantially across participants, distributing on a continuum from 5% to 22% of segments. The frequency of phonemic errors was significantly greater than the frequency of distortion errors, which, in turn, was greater than the frequency of distorted substitution errors. The most common distortion qualities were voicing ambiguity and segment lengthening, but over 40% of distortion errors were distributed across an assortment of tongue modifications. Conclusions The results replicated observations from previous studies of speakers with quantitatively defined AOS in a new sample of participants with clinically diagnosed AOS. Similar distortion qualities were observed across studies, offering focus for diagnosticians and guidance for operationalizing future measures. The broad performance continua we observed help explain why binary classification of the presence/absence of AOS can be challenging and indicate a need to develop quantitative norms.

Effect Size Benchmarks for Response Elaboration Training: A Meta-Analysis.

Purpose With a number of single-case experimental design studies reporting the effects of treatment for response (and modified response) elaboration training (RET/M-RET), it is important to consolidate data over multiple participants to allow comparison within/between individuals and across similar treatments. The purpose of this study was to conduct a meta-analysis of single-case experimental design studies of RET/M-RET and to determine effect size (ES) benchmarks to allow comparison to "group" data. Method Database and bibliographical searches identified 20 investigations of RET/M-RET. Nine studies had sufficient experimental quality, compliance with the essential components of the RET protocol, and consistency in the dependent variable (i.e., accurate content production in response to picture stimuli) to be retained for the meta-analysis. Probe data for a total of 26 persons with aphasia (PWA) were extracted from published graphs (if raw data were not available) to calculate weighted ESs at the end of treatment and at follow-up for both treated and untreated stimuli. The first, second, and third quartiles of the distributions were used to serve at benchmarks for small, medium, and large effects. Results Nearly all participants demonstrated positive effects as a result of RET/M-RET, indicating an association with positive changes in content production for PWA. Small, medium, and large benchmarks are reported for treated items after treatment and at follow-up, as well as for untreated items after treatment and at follow-up. Conclusions With a larger sample of 26 participants, this analysis indicates that RET/M-RET are associated with positive changes in content production for PWA. ES benchmarks allow clinicians/researchers to compare an individual's performance across multiple applications of treatment to performance of other PWA and to other treatments with similar outcomes.

Interrater Reliability and Concurrent Validity for the Apraxia of Speech Rating Scale 3.0: Application With Persons With Acquired Apraxia of Speech and Aphasia.

Purpose This investigation was designed to provide interrater reliability data for the Apraxia of Speech Rating Scale 3.0 (ASRS 3.0; Strand, Duffy, Clark, & Josephs, 2014 ). Importantly, ratings were completed by investigators who were not involved with the ASRS development. Another aim was to evaluate the relationship of the ASRS 3.0 total score to word intelligibility. Method Two investigators independently completed ASRS 3.0 ratings for 28 participants with chronic apraxia of speech and aphasia. Intelligibility scores were obtained for all participants. Results Consistency of ratings for each feature and total score of the ASRS 3.0 was measured using intraclass correlation coefficients. Twelve of 13 intraclass correlation coefficients for feature ratings reached significance; clinical meaningfulness ranged from poor to excellent. Interrater reliability for the total scores was excellent. Similarly, absolute difference of ratings was minimal for the total scores, but varied across the 13 feature ratings. Correlations between the intelligibility scores and ASRS 3.0 total score were moderate to strong. Conclusion The total ASRS 3.0 score may be viewed as a reliable indicator of prevalence of apraxia of speech features. Although there was good to acceptable correspondence in ratings of the majority of the individual features, additional operationalization of rating procedures may be needed to improve interrater reliability for a few features.

Language Changes Following Combined Aphasia and Apraxia of Speech Treatment.

Purpose: Combined Aphasia and Apraxia of Speech Treatment (CAAST) is a newly developed treatment shown to increase production of accurate content in narrative discourse for persons with aphasia and apraxia of speech. The purpose of this post hoc study was to further describe lexical and morphosyntactic changes associated with changes in content production. Method: Existing probe data from 8 persons with aphasia who had completed CAAST were used to complete analyses of morphosyntactic production, lexical diversity, and novelty of content. Language analyses were completed using discourse samples obtained at numerous pretreatment and posttreatment intervals. Results: All participants demonstrated gains in morphosyntactic language output for treated items, which extended to untreated sets for 7 participants. All 8 increased in production of novel content. Lexical diversity increases were evident for most participants. Although there were some similarities in language changes, there was substantial variability across response profiles. Conclusion: CAAST, previously associated with positive treatment effects for production of accurate content, also appears to facilitate acquisition and generalization of morphosyntactic complexity, lexical diversity, and novelty of content for individuals with nonfluent aphasia. Further investigation is needed to determine causality and appropriate clinical application. Supplemental Material: https://doi.org/10.23641/asha.5912530.

Combined aphasia and apraxia of speech treatment (CAAST): Systematic replications in the development of a novel treatment.

PURPOSE: The purpose of this investigation was to examine the effects of a modified version of a newly developed therapy for aphasia and acquired apraxia of speech (AOS), Combined Aphasia and Apraxia of Speech Treatment (CAAST). METHOD: Four speakers with chronic AOS and aphasia received CAAST in the context of multiple baseline designs. Dependent variables included language measures (i.e. production of correct information units (CIUs)) and speech production measures (i.e. speech intelligibility and percent correct consonants (PCC) in sentence repetition). RESULT: Three of the participants demonstrated improved CIU production with treated picture sets and two also demonstrated generalization to untreated sets. All participants achieved substantially increased CIU production in an untrained discourse context. Speech intelligibility increased for three of the participants and increases in PCC were observed for all of the participants at two weeks post-treatment. However, PCC improvements were maintained for only two of the speakers at six weeks post-treatment. CONCLUSION: The revised CAAST protocol was associated with improved changes in speech and generalization across contexts in comparison to the previous iteration of CAAST. However, focus on sentence production in generalization practice may have been detrimental to CIU production for one participant.

Effects of Treatment Intensity on Outcomes in Acquired Apraxia of Speech.

Purpose: This investigation was designed to examine the effects of treatment intensity (i.e., dose frequency) on the outcomes of Sound Production Treatment (SPT) for acquired apraxia of speech. Method: Five men with chronic apraxia of speech and aphasia received both intense SPT (3 hr per day/3 days per week) and nonintense/traditional SPT (SPT-T; 1 hr per day/3 days per week) in the context of single-case experimental designs. Each treatment was applied separately to a designated set of experimental words with 1 treatment applied at a time. Twenty-seven treatment sessions were conducted with each phase of treatment. Accuracy of articulation of target sounds within treated and untreated experimental words was measured during the course of the investigation. Results: All participants demonstrated improved articulation with both treatment intensities. Better maintenance of gains for treated items was found with SPT-T for 2 participants as measured at an 8-week posttreatment retention probe. Superior maintenance of increased accuracy of production of untreated items was also observed with SPT-T for all participants. Conclusion: A less intense (distributed) application of SPT facilitated better maintenance of improved articulatory accuracy for untreated items, and in some cases treated items, than intense SPT. Supplemental Materials: https://doi.org/10.23641/asha.5734053.