Phoneme-based rehabilitation of anomia in aphasia

A Meta-Analysis of Anomia Treatment in Bilingual Aphasia: Within- and Cross-Language Generalization and Predictors of the Treatment Outcomes

PURPOSE

The present meta-analysis investigated the efficacy of anomia treatment in bilingual and multilingual persons with aphasia (BPWAs) by assessing the magnitudes of six anomia treatment outcomes. Three of the treatment outcomes pertained to the "trained language": improvement of trained words (treatment effect [TE]), within-language generalization of semantically related untrained words (WLG-Related), and within-language generalization of unrelated words (WLG-Unrelated). Three treatment outcomes were for the "untrained language": improvement of translations of the trained words (cross-language generalization of trained words [CLG-Tx]), cross-language generalization of semantically related untrained words (CLG-Related), and cross-language generalization of unrelated untrained words (CLG-Unrelated). This study also examined participant- and treatment-related predictors of these treatment outcomes.

METHOD

This study is registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42023418147. Nine electronic databases were searched to identify word retrieval treatment studies of poststroke BPWAs of at least 6 months postonset. Pre- and posttreatment single-word naming scores were extracted for each eligible participant and used to calculate effect sizes (within-case Cohen's d) of the six treatment outcomes. Random-effects meta-analyses were conducted to assess weighted mean effect sizes of the treatment outcomes across studies. Multiple linear regression analyses were used to examine the effects of participant-related variables (pretreatment single-word naming and comprehension representing poststroke lexical processing abilities) and treatment-related variables (type, language, and duration). The methodological quality of eligible studies and the risk of bias in this meta-analysis were assessed.

RESULTS

A total of 17 published studies with 39 BPWAs were included in the meta-analysis. The methodological quality of the included studies ranged from fair (n = 4) to good (n = 13). Anomia treatment produced a medium effect size for TE (M = 8.36) and marginally small effect sizes for WLG-Related (M = 1.63), WLG-Unrelated (M = 0.68), and CLG-Tx (M = 1.56). Effect sizes were nonsignificant for CLG-Related and CLG-Unrelated. TE was significantly larger than the other five types of treatment outcomes. TE and WLG-Related effect sizes were larger for BPWAs with milder comprehension or naming impairments and for treatments of longer duration. WLG-Unrelated was larger when BPWAs received phonological treatment than semantic and mixed treatments. The overall risk of bias in the meta-analysis was low with a potential risk of bias present in the study identification process.

CONCLUSIONS

Current anomia treatment practices for bilingual speakers are efficacious in improving trained items but produce marginally small within-language generalization and cross-language generalization to translations of the trained items. These results highlight the need to provide treatment in each language of BPWAs and/or investigate other approaches to promote cross-language generalization. Furthermore, anomia treatment outcomes are influenced by BPWAs' poststroke single-word naming and comprehension abilities as well as treatment duration and the provision of phonological treatment.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25595712.

Generalization in Aphasia Treatment: A Tutorial for Speech-Language Pathologists

PURPOSE

Generalization has been defined and instantiated in a variety of ways over the last half-century, and this lack of consistency has created challenges for speech-language pathologists to plan for, implement, and measure generalization in aphasia treatment protocols. This tutorial provides an overview of generalization with a focus on how it relates to aphasia intervention, including a synthesis of existing principles of generalization and examples of how these can be embedded in approaches to aphasia treatment in clinical and research settings.

METHOD

Three articles collectively listing 20 principles of generalization formed the foundation for this tutorial. The seminal work of Stokes and Baer (1977) focused attention on generalization in behavioral change following treatment. Two aphasia-specific resources identified principles of generalization in relation to aphasia treatment (Coppens & Patterson, 2018; Thompson, 1989). A selective literature review was conducted to identify evidence-based examples of each of these 20 principles from the extant literature.

RESULTS

Five principles of generalization were synthesized from the original list of 20. Each principle was supported by studies drawn from the aphasia treatment literature to exemplify its application.

CONCLUSIONS

Generalization is an essential aspect of meaningful aphasia intervention. Successful generalization requires the same dedication to strategic planning and outcome measurement as the direct training aspect of intervention. Although not all people with aphasia are likely to benefit equally from each of the principles reviewed herein, our synthesis provides information to consider for maximizing generalization of aphasia treatment outcomes.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24714399.

Repetition Priming Treatment for Anomia: Effects of Single- and Multiple-Exemplar Protocols

INTRODUCTION

Repetition priming can lead to improved naming ability in people with aphasia, but concerns have arisen from prior research about using only a single picture exemplar for each target. Specifically, it is unclear whether the observed improvements were due to learning simple correspondences between particular words and pictures rather than changes at a deeper level of lexical-semantic processing. In addition, implications for generalization after training with single exemplars were unclear. This study replicated and extended previous work to address these questions.

METHOD

Five participants with chronic aphasia participated in this repeated-measures design study, which repeatedly paired words and pictures with no feedback provided. Two participants engaged in a single-exemplar condition, with a single picture exemplar of each target used for every presentation of that target. The remaining three participants engaged in a multiple-exemplar condition, with several different pictures used for each target. Half of these targets used training pictures during naming probes, whereas half did not.

RESULTS

Primed items led to greater improvements in naming than items that were practiced but not primed. The data indicate that improvements may extend beyond stimulus-specific correspondences. Maintenance and generalization effects were mixed.

CONCLUSIONS

These data provide further support for the efficacy of repetition priming treatment for anomia. Implications and future directions are discussed.

Therapies and Challenges in the Post-Stroke Aphasia Rehabilitation Arena: Current and Future Prospects

Aphasia is a serious consequence of stroke that results in a breakdown in communication. The course of aphasia recovery differs between afflicted individuals, and responsiveness to treatment cannot be predicted. Aphasiologists continue to investigate numerous behavioral treatment protocols that have shifted their focus to complimentary rehabilitation strategies. The aim of this study is threefold. First, to summarize the different categories of aphasia interventions post-stroke, considering their respective protocols, and present available evidence on the effectiveness of those protocols. Second, to document the challenges regarding the prediction of aphasia treatment response post-stroke in individual patients. Third, to report the challenges faced by researchers in recruiting people with aphasia (PWA) for treatment studies, and provide recommendations on how to increase participant recruitment and retention. This study provides up-to-date information on (i) effective therapies and aphasia recovery processes, and (ii) research recruitment hurdles together with potential strategies for overcoming them.

ParAlg: A Paraphasia Algorithm for Multinomial Classification of Picture Naming Errors

PURPOSE

A preliminary version of a paraphasia classification algorithm (henceforth called ParAlg) has previously been shown to be a viable method for coding picture naming errors. The purpose of this study is to present an updated version of ParAlg, which uses multinomial classification, and comprehensively evaluate its performance when using two different forms of transcribed input.

METHOD

A subset of 11,999 archival responses produced on the Philadelphia Naming Test were classified into six cardinal paraphasia types using ParAlg under two transcription configurations: (a) using phonemic transcriptions for responses exclusively (phonemic-only) and (b) using phonemic transcriptions for nonlexical responses and orthographic transcriptions for lexical responses (orthographic-lexical). Agreement was quantified by comparing ParAlg-generated paraphasia codes between configurations and relative to human-annotated codes using four metrics (positive predictive value, sensitivity, specificity, and F1 score). An item-level qualitative analysis of misclassifications under the best performing configuration was also completed to identify the source and nature of coding discrepancies.

RESULTS

Agreement between ParAlg-generated and human-annotated codes was high, although the orthographic-lexical configuration outperformed phonemic-only (weighted-average F1 scores of .78 and .87, respectively). A qualitative analysis of the orthographic-lexical configuration revealed a mix of human- and ParAlg-related misclassifications, the former of which were related primarily to phonological similarity judgments whereas the latter were due to semantic similarity assignment.

CONCLUSIONS

ParAlg is an accurate and efficient alternative to manual scoring of paraphasias, particularly when lexical responses are orthographically transcribed. With further development, it has the potential to be a useful software application for anomia assessment.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22087763.

Applying adaptive distributed practice to self-managed computer-based anomia treatment: A single-case experimental design

INTRODUCTION

There is a pressing need to improve computer-based treatments for aphasia to increase access to long-term effective evidence-based interventions. The current single case design incorporated two learning principles, adaptive distributed practice and stimuli variability, to promote acquisition, retention, and generalization of words in a self-managed computer-based anomia treatment.

METHODS

Two participants with post-stroke aphasia completed a 12-week adaptive distributed practice naming intervention in a single-case experimental design. Stimuli variability was manipulated in three experimental conditions: high exemplar variability, low exemplar variability, and verbal description prompt balanced across 120 trained words. Outcomes were assessed at 1-week, 1-month, and 3-months post-treatment. Statistical comparisons and effect sizes measured in the number of words acquired, generalized, and retained were estimated using Bayesian generalized mixed-effect models.

RESULTS

Participants showed large and robust acquisition, generalization, and retention effects. Out of 120 trained words, participant 1 acquired ∼77 words (trained picture exemplars) and ∼63 generalization words (untrained picture exemplars of treated words). Similarly, participant 2 acquired ∼57 trained words and ∼48 generalization words. There was no reliable change in untrained control words for either participant. Stimuli variability did not show practically meaningful effects.

CONCLUSIONS

These case studies suggest that adaptive distributed practice is an effective method for re-training more words than typically targeted in anomia treatment research (∼47 words on average per Snell et al., 2010). Generalization across experimental conditions provided evidence for improved lexical access beyond what could be attributed to simple stimulus-response mapping. These effects were obtained using free, open-source flashcard software in a clinically feasible, asynchronous format, thereby minimizing clinical implementation barriers. Larger-scale clinical trials are required to replicate and extend these effects.

Identifying segmental and prosodic errors associated with the increasing word length effect in acquired apraxia of speech

Purpose: Individuals with stroke-related apraxia of speech (AOS) plus aphasia tend to produce more speech errors with increasing word length. The Words of Increasing Length task (WIL) uses a 3-point scale to score word accuracy but penalises for error types that can arise either from language or motor impairment, reducing the test's sensitivity and specificity. The purpose here was to identify error types explaining variance in the WIL score, and those associated with AOS and word length.Method: Speech errors were perceptually identified on the WIL task for 51 Australian English-speaking adults with stroke-related aphasia, 25 with concomitant AOS. Multiple regression and linear mixed effects modelling were applied.Result: Variance in WIL scores was best explained with four error types: consonant additions, incorrect number of syllables, false starts and consonant substitutions/distortions. False starts were significantly associated with AOS diagnosis. Incorrect number of syllables, consonant omissions, false starts, and lexical stress errors increased in frequency for longer words and, while the interaction with diagnosis did not reach significance, the effect appeared driven by the AOS group.Conclusion: Findings provide further support for using polysyllabic word production to assess apraxic speech. The WIL task has limitations that may bias patients' performance and clinicians' perceptual evaluation. Data provide valuable information for designing a more sensitive diagnostic protocol for AOS.

Semantic Versus Orthographic Preferences in Aphasia: Behavioral Evidence

In this study, we compared the orthographic and semantic preferences of healthy adults and age and gender matched adults with aphasia, an acquired language disorder. Previous research in word retrieval and word associations has addressed semantic and phonological connections, but it has not as often included analyses of orthographic skills. We matched (on age and gender) 10 neurotypical adults and 11 older adults with aphasia and administered to both groups a lexical discrimination task requiring them to select, from 18 choices, those words that were most different from three words (daughter, laughter, son). Among the choices were foil words (e.g., daughter), orthographic similarities (laughter) and semantic similarities (son). Results revealed that individuals with aphasia focused on orthographic differences, while healthy adults chose semantic differences. Further studies should further explore this orthographic focus to develop treatment strategies, using behavioral and objective measures, for word-finding deficits in aphasia.

Behavioral interventions for poststroke aphasia

There is a long history of behavioral interventions for poststroke aphasia with hundreds of studies supporting the benefits of aphasia treatment. However, interventions for aphasia are complex with many interacting components, and no one treatment is appropriate for all persons with aphasia. We present a novel, simple framework for classifying aphasia interventions. The framework is incorporated within the overarching International Classification of Functioning, Disability, and Health (ICF) model and is consistent with the commonly-held definition that aphasia is a multimodality disorder that impairs, in varying degrees, the understanding and expression of both oral and written language modalities. Furthermore, within the language impairment level, it distinguishes between the linguistic areas of phonology, semantics, and syntax that may be impaired individually or in combination. We define the terminology of the proposed framework and then categorize some common examples of behavioral interventions for post-stroke aphasia. We describe some of these interventions in greater detail to illustrate the extensive toolbox of evidence-based treatments for aphasia. We address some key issues that clinicians, usually speech-language pathologists, consider when selecting interventions for their specific patients with aphasia, including dose. Finally, we address various models of service delivery for persons with aphasia such as Intensive Comprehensive Aphasia Programs (ICAPs) and Aphasia Centers.

Repetition Priming in Treatment of Anomia

PURPOSE

Repetition priming has been suggested as a method for targeting implicit processes in anomia treatment. Prior studies have used masked priming for this purpose. This study extends that work with visible primes, a more clinically feasible approach.

METHOD

This study used a single-subject design across three participants with aphasia. Treatment involved repeated exposure to identity primes (trained condition) or sham primes (untrained condition) paired with pictures. Analyses assessed acquisition effects for trained items and untrained items that were seen during the training period, generalization to untrained items that had not been seen, and generalization to broader language skills, immediately and 3 months post-treatment.

RESULTS

All participants improved in naming trained items immediately after treatment, with greater improvements for trained than for untrained items. All participants maintained some degree of improvement on trained items 3 months post-treatment, although the degree differed across participants. Inconsistent generalization occurred to unexposed items. Improvements were noted in some areas of broader language ability, although these varied.

CONCLUSIONS

These data suggest a repetition priming treatment paradigm may increase naming accuracy for individuals with anomia and may benefit other aspects of language. Participant factors may have influenced response to treatment. Directions for future investigation are discussed.

A Randomized Controlled Trial of the Effects of Group Conversation Treatment on Monologic Discourse in Aphasia

PURPOSE

Evidence has shown that group conversation treatment may improve communication and reduce social isolation for people with aphasia. However, little is known about the impact of conversation group treatment on measures of discourse. This project explored the impact of conversation treatment on measures of monologic discourse.

METHOD

In this randomized controlled trial, 48 participants with chronic aphasia were randomly assigned to dyadic, large group, or control conditions. Conversation group treatment was provided for 1 hr, twice per week, for 10 weeks. Discourse samples were collected and coded at pretreatment, posttreatment, and 6-week maintenance. There were three narrative tasks: (a) Comprehensive Aphasia Test (CAT) picture description, (b) Cat Rescue Picture, and (c) Cinderella retell. All narratives were coded using the percent correct information units (percent CIUs), the CAT standardized narrative analysis method, and the complete utterance (CU) method.

RESULTS

No significant changes were observed on percent CIU, which was the primary outcome measure. The treated groups demonstrated improvement on aspects of the CU method following treatment, whereas the control group did not. Significant changes were observed for other CIU measures and the CAT standardized narrative analysis in both the treated and control groups.

CONCLUSIONS

The results suggest that the CU measures were more sensitive to the effects of conversation treatment in monologic discourse compared to CIU and CAT measures. Changes were more common in absolute rather than relative values, suggesting that conversation treatment impacts the overall amount of language produced rather than efficiency of production.

Individualized response to semantic versus phonological aphasia therapies in stroke

Attempts to personalize aphasia treatment to the extent where it is possible to reliably predict individual response to a particular treatment have yielded inconclusive results. The current study aimed to (i) compare the effects of phonologically versus semantically focussed naming treatment and (ii) examine biographical and neuropsychological baseline factors predictive of response to each treatment. One hundred and four individuals with chronic post-stroke aphasia underwent 3 weeks of phonologically focussed treatment and 3 weeks of semantically focussed treatment in an unblinded cross-over design. A linear mixed-effects model was used to compare the effects of treatment type on proportional change in correct naming across groups. Correlational analysis and stepwise regression models were used to examine biographical and neuropsychological predictors of response to phonological and semantic treatment across all participants. Last, chi-square tests were used to explore the association between treatment response and phonological and semantic deficit profiles. Semantically focussed treatment was found to be more effective at the group-level, independently of treatment order (P = 0.041). Overall, milder speech and language impairment predicted good response to semantic treatment (r range: 0.256-0.373) across neuropsychological tasks. The Western Aphasia Battery-Revised Spontaneous Speech score emerged as the strongest predictor of semantic treatment response (R 2 = 0.188). Severity of stroke symptoms emerged as the strongest predictor of phonological treatment response (R 2 = 0.103). Participants who showed a good response to semantic treatment were more likely to present with fluent speech compared to poor responders (P = 0.005), whereas participants who showed a good response to phonological treatment were more likely to present with apraxia of speech (P = 0.020). These results suggest that semantic treatment may be more beneficial to the improvement of naming performance in aphasia than phonological treatment, at the group-level. In terms of personalized predictors, participants with relatively mild impairments and fluent speech responded better to semantic treatment, while phonological treatment benefitted participants with more severe impairments and apraxia of speech.

Current Approaches to the Treatment of Post-Stroke Aphasia

Aphasia, impairment of language after stroke or other neurological insult, is a common and often devastating condition that affects nearly every social activity and interaction. Behavioral speech and language therapy is the mainstay of treatment, although other interventions have been introduced to augment the effects of the behavioral therapy. In this narrative review, we discuss advances in aphasia therapy in the last 5 years and focus primarily on properly powered, randomized, controlled trials of both behavioral therapies and interventions to augment therapy for post-stroke aphasia. These trials include evaluation of behavioral therapies and computer-delivered language therapies. We also discuss outcome prediction trials as well as interventional trials that have employed noninvasive brain stimulation, or medications to augment language therapy. Supported by evidence from Phase III trials and large meta-analyses, it is now generally accepted that aphasia therapy can improve language processing for many patients. Not all patients respond similarly to aphasia therapy with the most severe patients being the least likely responders. Nevertheless, it is imperative that all patients, regardless of severity, receive aphasia management focused on direct therapy of language deficits, counseling, or both. Emerging evidence from Phase II trials suggests transcranial brain stimulation is a promising method to boost aphasia therapy outcomes.

Effects of Semantic Feature Type, Diversity, and Quantity on Semantic Feature Analysis Treatment Outcomes in Aphasia

Purpose Semantic feature analysis (SFA) is a naming treatment found to improve naming performance for both treated and semantically related untreated words in aphasia. A crucial treatment component is the requirement that patients generate semantic features of treated items. This article examined the role feature generation plays in treatment response to SFA in several ways: It attempted to replicate preliminary findings from Gravier et al. (2018), which found feature generation predicted treatment-related gains for both trained and untrained words. It examined whether feature diversity or the number of features generated in specific categories differentially affected SFA treatment outcomes. Method SFA was administered to 44 participants with chronic aphasia daily for 4 weeks. Treatment was administered to multiple lists sequentially in a multiple-baseline design. Participant-generated features were captured during treatment and coded in terms of feature category, total average number of features generated per trial, and total number of unique features generated per item. Item-level naming accuracy was analyzed using logistic mixed-effects regression models. Results Producing more participant-generated features was found to improve treatment response for trained but not untrained items in SFA, in contrast to Gravier et al. (2018). There was no effect of participant-generated feature diversity or any differential effect of feature category on SFA treatment outcomes. Conclusions Patient-generated features remain a key predictor of direct training effects and overall treatment response in SFA. Aphasia severity was also a significant predictor of treatment outcomes. Future work should focus on identifying potential nonresponders to therapy and explore treatment modifications to improve treatment outcomes for these individuals. Supplemental Material https://doi.org/10.23641/asha.12462596.

Effects of Phonomotor Therapy and Semantic Feature Analysis on Discourse Production

Background Anomia treatments typically focus on single word retrieval, although the ultimate goal of treatment is to improve functional communication at the level of discourse in daily situations. Aims The focus of this study was to investigate the impact of two effective anomia treatments on discourse production as measured by a story retell task. Method and Procedure Fifty-seven people with aphasia were randomized to receive either a phoneme-based treatment, Phonomotor Therapy (PMT; 28 participants), or a lexical-semantic treatment, Semantic Feature Analysis (SFA; 29 participants). Groups were matched for age, aphasia severity, education, and years post onset. All received 56-60 hr of treatment in a massed treatment schedule. Therapy was delivered for a total of 8-10 hr/week over the course of 6-7 weeks. All participants completed testing 1 week prior to treatment (A1), immediately following treatment (A2), and again 3 months later (A3). Discourse was analyzed through the percentage of correct information units at each time point. Outcomes and Results Both groups showed nonsignificant improvements from pretreatment to immediately posttreatment. The PMT group showed significant improvement 3 months posttreatment, while the SFA group returned to near-baseline levels. Conclusion These results add to our understanding of the effects of both PMT and SFA. Future research should address understanding variability in discourse outcomes across studies and the effects of aphasia severity and individual participant and treatment factors on treatment outcomes for both of these approaches.

Effect of speech therapy intervention program for non-fluent aphasic patients after stroke

PURPOSE

the objective of this paper is to verify the effect of speech therapy intervention program in patients with non-fluent aphasia due to stroke in language tasks related to verbal fluency in semantic and phonological categories.

METHODS

Patients with aphasia due to stroke were selected to take part in this study. Two groups were formed: diagnosed patients with Broca/transcortical motor aphasia (GA), and a control group (healthy individuals). GA took a fluency verbal task (FAS, other complementary categories: phonological /p/ /l/ and semantic: "fruits" and "names"). These patients were all engaged in a language intervention program developed by the authors of this study. GA received speech therapy sessions (ten sessions lasting for an hour once a week), following a specific language program. After the sessions, the patients were re-evaluated.

RESULTS

GA had statistical significant improvement in the verbal fluency task after the speech therapy program (p-value < 0,001).

CONCLUSION

The speech language therapy program we proposed was efficient enough to show improvement in the results for GA in the verbal fluency task.

The Challenge of Achieving Greater Generalization in Phonological Treatment of Aphasia

BACKGROUND

Stimulus selection is important to anomia treatment because similarity between trained and untrained words in the mental lexicon may influence treatment generalization. We focused on phonological similarity between trained and untrained words from a clinical trial of Phonomotor Treatment (PMT) that showed gains in confrontation naming accuracy of untrained words post-treatment. One way to capture the amount of similarity between the trained and untrained words is to consider the phonological network path distance between words. We posited that the distance between trained and untrained words in a phonological network could account for the improvement in confrontation naming accuracy post-treatment.

AIM

To define the phonological network distance between trained and untrained words that influences change in confrontation naming accuracy post-treatment.

METHODS AND PROCEDURES

We retrospectively analyzed data from 28 people with aphasia who received PMT as part of a clinical trial. Participants completed confrontation naming (baseline, post-treatment, and 3-months post-treatment) of words varying in phonological distance to the treatment stimuli. We used a phonological network to calculate the average shortest path length (ASPL), defined by number of phoneme differences, between an untrained word and all trained words. We used mixed effects regression models to predict change in confrontation naming accuracy of untrained words post-treatment from ASPL. Several post-hoc analyses were also conducted.

OUTCOMES AND RESULTS

We found no effect of ASPL on change in confrontation naming accuracy of untrained words immediately post- and 3-months post-treatment. However, post-hoc analyses indicated significant subject heterogeneity and limitations in observable path distance between trained and untrained words.

CONCLUSION

Despite the clinical trial report that confrontation naming of untrained words improved after PMT, we found no overall effect of ASPL on the amount of improvement. We discuss further investigation of the entire domain of phonological sequence knowledge (the phonological sequence knowledge landscape) and its influence on treatment generalization, and the potential importance of identifying predictors of treatment response to enhance the effects of treatment generalization.

A Phonomotor Approach to Apraxia of Speech Treatment

Purpose This study continued Phase I investigation of a modified Phonomotor Treatment (PMT) Program on motor planning in two individuals with apraxia of speech (AOS) and aphasia and, with support from prior work, refined Phase I methodology for treatment intensity and duration, a measure of communicative participation, and the use of effect size benchmarks specific to AOS. Method A single-case experimental design with multiple baselines across behaviors and participants was used to examine acquisition, generalization, and maintenance of treatment effects 8-10 weeks posttreatment. Treatment was distributed 3 days a week, and duration of treatment was specific to each participant (criterion based). Experimental stimuli consisted of target sounds or clusters embedded nonwords and real words, specific to each participants' deficit. Results Findings show improved repetition accuracy for targets in trained nonwords, generalization to targets in untrained nonwords and real words, and maintenance of treatment effects at 10 weeks posttreatment for one participant and more variable outcomes for the other participant. Conclusions Results indicate that a modified version of PMT can promote generalization and maintenance of treatment gains for trained speech targets via a multimodal approach emphasizing repeated exposure and practice. While these results are promising, the frequent co-occurrence of AOS and aphasia warrants a treatment that addresses both motor planning and linguistic deficits. Thus, the application of traditional PMT with participant-specific modifications for AOS embedded into the treatment program may be a more effective approach. Future work will continue to examine and maximize improvements in motor planning, while also treating anomia in aphasia.

Neural Population Dynamics and Cognitive Function

Representations in the brain are encoded as patterns of activity of large populations of neurons. The science of population encoded representations, also known as parallel distributed processing (PDP), achieves neurological verisimilitude and has been able to account for a large number of cognitive phenomena in normal people, including reaction times (and reading latencies), stimulus recognition, the effect of stimulus salience on attention, perceptual invariance, simultaneous egocentric and allocentric visual processing, top-down/bottom-up processing, language errors, the effect of statistical regularities of experience, frequency, and age of acquisition, instantiation of rules and symbols, content addressable memory and the capacity for pattern completion, preservation of function in the face of noisy or distorted input, inference, parallel constraint satisfaction, the binding problem and gamma coherence, principles of hippocampal function, the location of knowledge in the brain, limitations in the scope and depth of knowledge acquired through experience, and Piagetian stages of cognitive development. PDP studies have been able to provide a coherent account for impairment in a variety of language functions resulting from stroke or dementia in a large number of languages and the phenomenon of graceful degradation observed in such studies. They have also made important contributions to our understanding of attention (including hemispatial neglect), emotional function, executive function, motor planning, visual processing, decision making, and neuroeconomics. The relationship of neural network population dynamics to electroencephalographic rhythms is starting to emerge. Nevertheless, PDP approaches have scarcely penetrated major areas of study of cognition, including neuropsychology and cognitive neuropsychology, as well as much of cognitive psychology. This article attempts to provide an overview of PDP principles and applications that addresses a broader audience.

Phonomotor Versus Semantic Feature Analysis Treatment for Anomia in 58 Persons With Aphasia: A Randomized Controlled Trial

Purpose The ultimate goal of anomia treatment should be to achieve gains in exemplars trained in the therapy session, as well as generalization to untrained exemplars and contexts. The purpose of this study was to test the efficacy of phonomotor treatment, a treatment focusing on enhancement of phonological sequence knowledge, against semantic feature analysis (SFA), a lexical-semantic therapy that focuses on enhancement of semantic knowledge and is well known and commonly used to treat anomia in aphasia. Method In a between-groups randomized controlled trial, 58 persons with aphasia characterized by anomia and phonological dysfunction were randomized to receive 56-60 hr of intensively delivered treatment over 6 weeks with testing pretreatment, posttreatment, and 3 months posttreatment termination. Results There was no significant between-groups difference on the primary outcome measure (untrained nouns phonologically and semantically unrelated to each treatment) at 3 months posttreatment. Significant within-group immediately posttreatment acquisition effects for confrontation naming and response latency were observed for both groups. Treatment-specific generalization effects for confrontation naming were observed for both groups immediately and 3 months posttreatment; a significant decrease in response latency was observed at both time points for the SFA group only. Finally, significant within-group differences on the Comprehensive Aphasia Test-Disability Questionnaire (Swinburn, Porter, & Howard, 2004) were observed both immediately and 3 months posttreatment for the SFA group, and significant within-group differences on the Functional Outcome Questionnaire (Glueckauf et al., 2003) were found for both treatment groups 3 months posttreatment. Discussion Our results are consistent with those of prior studies that have shown that SFA treatment and phonomotor treatment generalize to untrained words that share features (semantic or phonological sequence, respectively) with the training set. However, they show that there is no significant generalization to untrained words that do not share semantic features or phonological sequence features.

The Influence of Phonomotor Treatment on Word Retrieval: Insights From Naming Errors

Purpose An increasing number of anomia treatment studies have coupled traditional word retrieval accuracy outcome measures with more fine-grained analysis of word retrieval errors to allow for more comprehensive measurement of treatment-induced changes in word retrieval. The aim of this study was to examine changes in picture naming errors after phonomotor treatment. Method Twenty-eight individuals with aphasia received 60 hr of phonomotor treatment, an intensive, phoneme-based therapy for anomia. Confrontation naming was assessed pretreatment, immediately posttreatment, and 3 months posttreatment for trained and untrained nouns. Responses were scored for accuracy and coded for error type, and error proportions of each error type (e.g., semantic, phonological, omission) were compared: pre- versus posttreatment and pretreatment versus 3 months posttreatment. Results The group of treatment participants improved in whole-word naming accuracy on trained items and maintained their improvement. Treatment effects also generalized to untrained nouns at the maintenance testing phase. Additionally, participants demonstrated a decrease in proportions of omission and description errors on trained items immediately posttreatment. Conclusions Along with generalized improved whole-word naming accuracy, results of the error analysis suggest that a global (i.e., both lexical-semantic and phonological) change in lexical knowledge underlies the observed changes in confrontation naming accuracy following phonomotor treatment.

The Link Between Verbal Short-Term Memory and Anomia Treatment Gains

Purpose A significant relationship between verbal short-term memory (STM) and language performance in people with aphasia has been found across studies. However, very few studies have examined the predictive value of verbal STM in treatment outcomes. This study aims to determine if verbal STM can be used as a predictor of treatment success. Method Retrospective data from 25 people with aphasia in a larger randomized controlled trial of phonomotor treatment were analyzed. Digit and word spans from immediately pretreatment were run in multiple linear regression models to determine whether they predict magnitude of change from pre- to posttreatment and follow-up naming accuracy. Pretreatment, immediately posttreatment, and 3 months posttreatment digit and word span scores were compared to determine if they changed following a novel treatment approach. Results Verbal STM, as measured by digit and word spans, did not predict magnitude of change in naming accuracy from pre- to posttreatment nor from pretreatment to 3 months posttreatment. Furthermore, digit and word spans did not change from pre- to posttreatment or from pretreatment to 3 months posttreatment in the overall analysis. A post hoc analysis revealed that only the less impaired group showed significant changes in word span scores from pretreatment to 3 months posttreatment. Discussion The results suggest that digit and word spans do not predict treatment gains. In a less severe subsample of participants, digit and word span scores can change following phonomotor treatment; however, the overall results suggest that span scores may not change significantly. The implications of these findings are discussed within the broader purview of theoretical and empirical associations between aphasic language and verbal STM processing.

Benchmarks of Significant Change After Aphasia Rehabilitation

OBJECTIVE

To establish benchmarks of significant change for aphasia rehabilitation outcome measures (ie, Western Aphasia Battery-Aphasia Quotient [WAB-AQ], Communicative Effectiveness Index [CETI], Boston Naming Test [BNT]) and assess if those benchmarks significantly differ across subgroups (ie, time post onset, dose frequency, treatment type).

DATA SOURCES

A comprehensive literature search of 12 databases, reference lists of previous reviews, and evidence-based practice materials was conducted.

STUDY SELECTION

Randomized controlled trials, quasi-experimental studies, single-subject design, and case studies that used a standardized outcome measure to assess change were included. Titles and full-text articles were screened using a dual review process. Seventy-eight studies met criteria for inclusion.

DATA EXTRACTION

Data were extracted independently, and 25% of extractions were checked for reliability. All included studies were assigned quality indicator ratings and an evidence level.

DATA SYNTHESIS

Random-effects meta-analyses were conducted separately for each study design group (ie, within-/between-group comparisons). For within-group designs, the summary effect size after aphasia rehabilitation was 5.03 points (95% confidence interval, 3.95-6.10, P<.001) on the WAB-AQ, 10.37 points (6.08-14.66, P<.001) on the CETI, and 3.30 points (2.43-4.18, P<.001) on the BNT. For between-group designs, the summary effect size was 5.05 points (1.64-8.46, P=.004) on the WAB-AQ and 0.55 points (-1.33 to 2.43, P=.564) on the BNT, the latter of which was not significant. Subgroup analyses for the within-group designs showed no significant differences in the summary effect size as a function of dose frequency or treatment type.

CONCLUSIONS

This study established benchmarks of significant change on 3 standardized outcome measures used in aphasia rehabilitation.

The Subjective Experience of Inner Speech in Aphasia Is a Meaningful Reflection of Lexical Retrieval

Purpose Individuals with aphasia often report that they feel able to say words in their heads, regardless of speech output ability. Here, we examine whether these subjective reports of successful "inner speech" (IS) are meaningful and test the hypothesis that they reflect lexical retrieval. Method Participants were 53 individuals with chronic aphasia. During silent picture naming, participants reported whether or not they could say the name of each item inside their heads. Using the same items, they also completed 3 picture-based tasks that required phonological retrieval and 3 matched auditory tasks that did not. We compared participants' performance on these tasks for items they reported being able to say internally versus those they reported being unable to say internally. Then, we examined the relationship of psycholinguistic word features to self-reported IS and spoken naming accuracy. Results Twenty-six participants reported successful IS on nearly all items, so they could not be included in the item-level analyses. These individuals performed correspondingly better than the remaining participants on tasks requiring phonological retrieval, but not on most other language measures. In the remaining group ( n = 27), IS reports related item-wise to performance on tasks requiring phonological retrieval, but not to matched control tasks. Additionally, IS reports were related to 3 word characteristics associated with lexical retrieval, but not to articulatory complexity; spoken naming accuracy related to all 4 word characteristics. Six participants demonstrated evidence of unreliable IS reporting; compared with the group, they also detected fewer errors in their spoken responses and showed more severe language impairments overall. Conclusions Self-reported IS is meaningful in many individuals with aphasia and reflects lexical phonological retrieval. These findings have potential implications for treatment planning in aphasia and for our understanding of IS in the general population.

Effects of Phonomotor Treatment on discourse production

BACKGROUND

Aphasia is an acquired language disorder that makes it difficult for people to produce and comprehend language, with every person with aphasia (PWA) demonstrating difficulty accessing and selecting words (anomia). While aphasia treatments typically focus on a single aspect of language, such as word retrieval, the ultimate goal of aphasia therapy is to improve communication, which is best seen at the level of discourse.

AIMS

This retrospective study investigated the effects of one effective anomia therapy, Phonomotor Treatment, on discourse production.

METHODS & PROCEDURES

Twenty-six PWA participated in 60 hours of Phonomotor Treatment, which focuses on building a person's ability to recognise, produce, and manipulate phonemes in progressively longer non-word and real-word contexts. Language samples were collected prior to, immediately after, and three months after the treatment program. Percent Correct Information Units (CIUs) and CIUs per minute were calculated.

OUTCOMES & RESULTS

Overall, PWA showed significantly improved CIUs per minute, relative to baseline, immediately after treatment and three months later, as well as significantly improved percent CIUs, relative to baseline, three months following treatment.

CONCLUSIONS

Phonomotor Treatment, which focuses on phonological processing, can lead to widespread improvement throughout the language system, including to the functionally critical level of discourse production.

The effects of silent visuomotor cueing on word retrieval in Broca's aphasies: A pilot study

About a quarter of stroke patients worldwide suffer serious language disorders such as aphasias. Most common symptoms of Broca's aphasia are word naming disorders which highly impact verbal communication and the quality of life of aphasic patients. In order to recover disturbances in word retrieval, several cueing methods (i.e. phonemic and semantic) have been established to improve lexical access establishing effective language rehabilitation techniques. Based on recent evidence from action-perception theories, which postulate that neural circuits for speech perception and articulation are tightly coupled, in the present work, we propose and investigate an alternative type of cueing using silent articulation-related visual stimuli. We hypothesize that providing patients with primes in the form of silent videos showing lip motions representative of correct pronunciation of target words, will result in faster word retrieval than when no such cue is provided. To test our prediction, we realize a longitudinal clinical virtual reality-based trial with four post-stroke Broca's patients and compare the interaction times between the two conditions over the eight weeks of the therapy. Our results suggest that silent visuomotor cues indeed facilitate word retrieval and verbal execution, and might be beneficial in lexical relearning in chronic Broca's patients.

Masked Repetition Priming Treatment for Anomia

PURPOSE

Masked priming has been suggested as a way to directly target implicit lexical retrieval processes in aphasia. This study was designed to investigate repeated use of masked repetition priming to improve picture naming in individuals with anomia due to aphasia.

METHOD

A single-subject, multiple-baseline design was used across 6 people with aphasia. Training involved repeated exposure to pictures that were paired with masked identity primes or sham primes. Two semantic categories were trained in series for each participant. Analyses assessed treatment effects, generalization within and across semantic categories, and effects on broader language skills, immediately and 3 months after treatment.

RESULTS

Four of the 6 participants improved in naming trained items immediately after treatment. Improvements were generally greater for items that were presented in training with masked identity primes than items that were presented repeatedly during training with masked sham primes. Generalization within and across semantic categories was limited. Generalization to broader language skills was inconsistent.

CONCLUSION

Masked repetition priming may improve naming for some individuals with anomia due to aphasia. A number of methodological and theoretical insights into further development of this treatment approach are discussed.

What Matters in Semantic Feature Analysis: Practice-Related Predictors of Treatment Response in Aphasia

PURPOSE

This study investigated the predictive value of practice-related variables-number of treatment trials delivered, total treatment time, average number of trials per hour, and average number of participant-generated features per trial-in response to semantic feature analysis (SFA) treatment.

METHOD

SFA was administered to 17 participants with chronic aphasia daily for 4 weeks. Individualized treatment and semantically related probe lists were generated from items that participants were unable to name consistently during baseline testing. Treatment was administered to each list sequentially in a multiple-baseline design. Naming accuracy for treated and untreated items was obtained at study entry, exit, and 1-month follow-up.

RESULTS

Item-level naming accuracy was analyzed using logistic mixed-effect regression models. The average number of features generated per trial positively predicted naming accuracy for both treated and untreated items, at exit and follow-up. In contrast, total treatment time and average trials per hour did not significantly predict treatment response. The predictive effect of number of treatment trials on naming accuracy trended toward significance at exit, although this relationship held for treated items only.

CONCLUSIONS

These results suggest that the number of patient-generated features may be more strongly associated with SFA-related naming outcomes, particularly generalization and maintenance, than other practice-related variables.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5734113.

Influence of Linguistic and Nonlinguistic Variables on Generalization and Maintenance Following Phonomotor Treatment for Aphasia

PURPOSE

Although phonomotor treatment shows promise as an effective intervention for anomia in people with aphasia, responses to this treatment are not consistent across individuals. To better understand this variability, we examined the influence of 5 participant characteristics-age, time postonset, aphasia severity, naming impairment, and error profile-on generalization and maintenance of confrontation naming and discourse abilities following phonomotor treatment.

METHOD

Using retrospective data from 26 participants with aphasia who completed a 6-week phonomotor treatment program, we examined the relationships between participant characteristics of interest and change scores on confrontation naming and discourse tasks, measured pretreatment, immediately following treatment, and 3 months following treatment.

RESULTS

Although the participant characteristics of aphasia severity and error profile appeared to predict generalization to improved confrontation naming of untrained items and discourse performance, a post hoc analysis revealed that no one characteristic predicted generalization across participants at 3 months posttreatment.

CONCLUSIONS

Response to phonomotor treatment does not appear to be influenced by aphasia and anomia severity level, error profile, participant age, or time postonset. Other factors, however, may influence response to intensive aphasia treatment and are worthy of continued exploration.

Less is more: neural mechanisms underlying anomia treatment in chronic aphasic patients

See Thompson and Woollams (doi:10.1093/brain/awx264) for a scientific commentary on this article. Previous research with aphasic patients has shown that picture naming can be facilitated by concurrent phonemic cueing [e.g. initial phoneme(s) of the word that the patient is trying to retrieve], both as an immediate word retrieval technique, and when practiced repeatedly over time as a long-term anomia treatment. Here, to investigate the neural mechanisms supporting word retrieval, we adopted—for the first time—a functional magnetic resonance imaging task using the same naming procedure as it occurs during the anomia treatment process. Before and directly after a 6-week anomia treatment programme, 18 chronic aphasic stroke patients completed our functional magnetic resonance imaging protocol—a picture naming task aided by three different types of phonemic cues (whole words, initial phonemes, final phonemes) and a noise-control condition. Patients completed a naming task based on the training materials, and a more general comprehensive battery of language tests both before and after the anomia treatment, to determine the effectiveness and specificity of the therapy. Our results demonstrate that the anomia treatment was effective and specific to speech production, significantly improving both patients’ naming accuracy and reaction time immediately post-treatment (unstandardized effect size: 29% and 17%, respectively; Cohen’s d: 3.45 and 1.83). Longer term gains in naming were maintained 3 months later. Functional imaging results showed that both immediate and long-term facilitation of naming involved a largely overlapping bilateral frontal network including the right anterior insula, inferior frontal and dorsal anterior cingulate cortices, and the left premotor cortex. These areas were associated with a neural priming effect (i.e. reduced blood oxygen level-dependent signal) during both immediate (phonemically-cued versus control-cue conditions), and long-term facilitation of naming (i.e. treated versus untreated items). Of note is that different brain regions were sensitive to different phonemic cue types. Processing of whole word cues was associated with increased activity in the right angular gyrus; whereas partial word cues (initial and final phonemes) recruited the left supplementary motor area, and right anterior insula, inferior frontal cortex, and basal ganglia. The recruitment of multiple and bilateral areas may help explain why phonemic cueing is such a successful behavioural facilitation tool for anomia treatment. Our results have important implications for optimizing current anomia treatment approaches, developing new treatments, and improving speech outcome for aphasic patients.

Reviewing the quality of discourse information measures in aphasia

BACKGROUND

Discourse is fundamental to everyday communication, and is an increasing focus of clinical assessment, intervention and research. Aphasia can affect the information a speaker communicates in discourse. Little is known about the psychometrics of the tools for measuring information in discourse, which means it is unclear whether these measures are of sufficient quality to be used as clinical outcome measures or diagnostic tools.

AIMS

To profile the measures used to describe information in aphasic discourse, and to assess the quality of these measures against standard psychometric criteria.

METHODS & PROCEDURES

A scoping review method was employed. Studies were identified using a systematic search of Scopus, Medline and Embase databases. Standard psychometric criteria were used to evaluate the measures' psychometric properties.

MAIN CONTRIBUTION

The current review summarizes and collates the information measures used to describe aphasic discourse, and evaluates their quality in terms of the psychometric properties of acceptability, reliability and validity. Seventy-six studies described 58 discourse information measures, with a mean of 2.28 measures used per study (SD = 1.29, range = 1-7). Measures were classified as 'functional' measures (n = 33), which focused on discourse macrostructure, and 'functional and structural' measures (n = 25), which focused on micro-linguistic and macro-structural approaches to discourse. There were no reports of the acceptability of data generated by the measures (distribution of scores, missing data). Test-retest reliability was reported for just 8/58 measures with 3/8 > 0.80. Intra-rater reliability was reported for 9/58 measures and in all cases percentage agreement was reported rather than reliability. Per cent agreement was also frequently reported for inter-rater reliability, with only 4/76 studies reporting reliability statistics for 12/58 measures; this was generally high (>.80 for 11/12 measures). The majority of measures related clearly to the discourse production model indicating content validity. A total of 36/58 measures were used to make 41 comparisons between participants with aphasia (PWA) and neurologically healthy participants (NHP), with 31/41 comparisons showing a difference between the groups. Four comparisons were made between discourse genres, with two measures showing a difference between genres, and two measures showing no difference.

CONCLUSIONS

There is currently insufficient information available to justify the use of discourse information measures as sole diagnostic or outcome measurement tools. Yet the majority of measures are rooted in relevant theory, and there is emerging evidence regarding their psychometric properties. There is significant scope for further psychometric strengthening of discourse information measurement tools.

Advances in neurocognitive rehabilitation research from 1992 to 2017: The ascension of neural plasticity

OBJECTIVE

The last 25 years have seen profound changes in neurocognitive rehabilitation that continue to motivate its evolution. Although the concept of nervous system plasticity was discussed by William James (1890), the foundation for experience-based plasticity had not reached the critical empirical mass to seriously impact rehabilitation research until after 1992. The objective of this review is to describe how the emergence of neural plasticity has changed neurocognitive rehabilitation research.

METHOD

The important developments included (a) introduction of a widely available tool that could measure brain plasticity (i.e., functional MRI); (b) development of new structural imaging techniques that could define limits of and opportunities for neural plasticity; (c) deployment of noninvasive brain stimulation to leverage neural plasticity for rehabilitation; (d) growth of a literature indicating that exercise has positively impacts neural plasticity, especially for older persons; and (e) enhancement of neural plasticity by creating interventions that generalize beyond the boundaries of treatment activities. Given the massive literature, each of these areas is developed by example.

RESULTS

The expanding influence of neural plasticity has provided new models and tools for neurocognitive rehabilitation in neural injuries and disorders, as well as methods for measuring neural plasticity and predicting its limits and opportunities. Early clinical trials have provided very encouraging results.

CONCLUSION

Now that neural plasticity has gained a firm foothold, it will continue to influence the evolution of neurocognitive rehabilitation research for the next 25 years and advance rehabilitation for neural injuries and disease. (PsycINFO Database Record

Language treatment prior to anterior temporal lobe surgery: Can naming skills be preserved?

Epilepsy affects 1% of the general population and is highly prevalent among Veterans. The purpose of this phase I study was to investigate a presurgical linguistically distributed language treatment program that could potentially diminish effects of proper-name retrieval deficits following left anterior temporal lobe resection for intractable epilepsy. A single-subject multiple-baseline design was employed for three individuals with late-onset chronic left temporal lobe epilepsy. Word retrieval treatment was administered prior to anterior temporal lobe resection. The primary outcome measure was confrontation naming of proper nouns. Immediately posttreatment (before surgery), there was a positive effect for all trained stimuli in the form of improved naming as compared with pretreatment. In addition, trained stimuli were found to be better after surgery than they were at pretreatment baseline, which would not be expected had language treatment not been provided. This series of case studies introduces two fundamentally novel concept: that commonly occurring deficits associated with left temporal lobe epilepsy can be treated despite the presence of damaged neural tissue and that providing this treatment prior to surgery can lead to better preservation of language function after surgery than would be expected if the treatment were not provided.

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.

Masked Repetition Priming in Treatment of Anomia: A Phase 2 Study

PURPOSE

Previous research has demonstrated that exposure to masked primes may improve naming accuracy for individuals with anomia. This study investigates the effect of repeated exposures to masked identity primes paired with pictures over multiple trials, sessions, and days on the ability of people with anomia to name those pictures.

METHOD

Four participants with anomia completed this single-subject, multiple-baseline design study. Twelve treatment sessions were conducted for each of 2 semantic categories. Comparisons of performance on naming probes were made between items that were primed, unprimed but seen the same number of times, and unprimed and seen only during naming probes.

RESULTS

All participants showed some gains in naming trained items although to varying degrees, and trained (primed) items generally showed greater improvement than untrained items seen the same number of times. Cross-category generalization was observed for some participants, but little to no within-category generalization occurred. Minimal changes occurred on measures of general language ability.

CONCLUSIONS

These data provide continued evidence that masked repetition priming can have a positive effect on naming for people with anomia. Factors that may influence participant response and additional questions that must be settled for this line of research to continue are discussed.

The Influence of Phonomotor Treatment on Word Retrieval Abilities in 26 Individuals With Chronic Aphasia: An Open Trial

PURPOSE

The ultimate goal of aphasia therapy should be to achieve gains in function that generalize to untrained exemplars and daily conversation. Anomia is one of the most disabling features of aphasia. The predominantly lexical/semantic approaches used to treat anomia have low potential for generalization due to the orthogonality of semantic and phonologic representations; this has been borne out in a meta-analysis of treatment studies. The intensive, neurally distributed, phonologic therapy reported here can, in principle, generalize to untrained phonologic sequences because of extant regularities in phonologic sequence knowledge and should, in principle, generalize to production of words trained as well as those untrained.

METHOD

Twenty-six persons with chronic aphasia due to stroke were treated, in a staggered (immediate vs. delayed treatment) open trial design, with 60 hr of intensive, multimodal therapy designed to enhance access to and efficiency of phonemes and phonologic sequences.

RESULTS

There was an absolute increase of 5% in confrontation naming of "untrained" nouns at 3 months, and there were 9% to 10% increases on measures of generalization of phonologic processes.

CONCLUSION

The results of this trial demonstrate generalization of training effects on laboratory measures, which were sustained at 3 months, and provide support for the theories that motivated the treatment.

Speech entrainment compensates for Broca's area damage

Speech entrainment (SE), the online mimicking of an audiovisual speech model, has been shown to increase speech fluency in patients with Broca's aphasia. However, not all individuals with aphasia benefit from SE. The purpose of this study was to identify patterns of cortical damage that predict a positive response SE's fluency-inducing effects. Forty-four chronic patients with left hemisphere stroke (15 female) were included in this study. Participants completed two tasks: 1) spontaneous speech production, and 2) audiovisual SE. Number of different words per minute was calculated as a speech output measure for each task, with the difference between SE and spontaneous speech conditions yielding a measure of fluency improvement. Voxel-wise lesion-symptom mapping (VLSM) was used to relate the number of different words per minute for spontaneous speech, SE, and SE-related improvement to patterns of brain damage in order to predict lesion locations associated with the fluency-inducing response to SE. Individuals with Broca's aphasia demonstrated a significant increase in different words per minute during SE versus spontaneous speech. A similar pattern of improvement was not seen in patients with other types of aphasia. VLSM analysis revealed damage to the inferior frontal gyrus predicted this response. Results suggest that SE exerts its fluency-inducing effects by providing a surrogate target for speech production via internal monitoring processes. Clinically, these results add further support for the use of SE to improve speech production and may help select patients for SE treatment.

The relation of object naming and other visual speech production tasks: a large scale voxel-based morphometric study

We report a lesion-symptom mapping analysis of visual speech production deficits in a large group (280) of stroke patients at the sub-acute stage (<120 days post-stroke). Performance on object naming was evaluated alongside three other tests of visual speech production, namely sentence production to a picture, sentence reading and nonword reading. A principal component analysis was performed on all these tests' scores and revealed a 'shared' component that loaded across all the visual speech production tasks and a 'unique' component that isolated object naming from the other three tasks. Regions for the shared component were observed in the left fronto-temporal cortices, fusiform gyrus and bilateral visual cortices. Lesions in these regions linked to both poor object naming and impairment in general visual-speech production. On the other hand, the unique naming component was potentially associated with the bilateral anterior temporal poles, hippocampus and cerebellar areas. This is in line with the models proposing that object naming relies on a left-lateralised language dominant system that interacts with a bilateral anterior temporal network. Neuropsychological deficits in object naming can reflect both the increased demands specific to the task and the more general difficulties in language processing.

Rehabilitation of lexical and semantic communicative impairments: An overview of available approaches

Lexical-semantic impairments are common consequences of acquired neurological damage. However, little is known about the benefits of existing treatment methods for this type of language impairment.

Description of an intensive residential aphasia treatment program: rationale, clinical processes, and outcomes

PURPOSE

The purpose of this article is to describe the rationale, clinical processes, and outcomes of an intensive comprehensive aphasia program (ICAP).

METHOD

Seventy-three community-dwelling adults with aphasia completed a residentially based ICAP. Participants received 5 hr of daily 1:1 evidence-based cognitive-linguistically oriented aphasia therapy, supplemented with weekly socially oriented and therapeutic group activities over a 23-day treatment course. Standardized measures of aphasia severity and communicative functioning were obtained at baseline, program entry, program exit, and follow-up. Results were analyzed using a Bayesian latent growth curve model with 2 factors representing (a) the initial level and (b) change over time, respectively, for each outcome measure.

RESULTS

Model parameter estimates showed reliable improvement on all outcome measures between the initial and final assessments. Improvement during the treatment interval was greater than change observed across the baseline interval, and gains were maintained at follow-up on all measures.

CONCLUSIONS

The rationale, clinical processes, and outcomes of a residentially based ICAP have been described. ICAPs differ with respect to treatments delivered, dosing parameters, and outcomes measured. Specifying the defining components of complex interventions, establishing their feasibility, and describing their outcomes are necessary to guide the development of controlled clinical trials.

Effects of intensive phonomotor treatment on reading in eight individuals with aphasia and phonological alexia

PURPOSE

The aim of this study was to investigate effects of a multimodal treatment of phonology, phonomotor treatment, on the reading abilities of persons with aphasia (PWA) with phonological alexia.

METHOD

In a retrospective, single-group design, this study presents pre-, post-, and 3-months posttreatment data for 8 PWA with phonological alexia. Participants completed 60 hr of phonomotor treatment over 6 weeks. Wilcoxon signed-ranks tests and group effect sizes comparing pre-, immediately post-, and 3-months posttreatment performance on tests of phonological processing and reading were performed.

RESULTS

Group data showed phonological processing and oral reading of real words and nonwords improved significantly posttreatment; these gains were maintained 3 months later. No group improvement was found for reading comprehension; however, one individual did show improvement immediately post- and 3-months posttreatment.

CONCLUSIONS

This study provides support that phonomotor treatment is a viable approach to improve phonological processing and oral reading for PWA with phonological alexia. The lack of improvement with comprehension is inconsistent with prior work using similar treatments (Conway et al., 1998; Kendall et al., 2003). However, this difference can, in part, be accounted for by differences in variables, such as treatment intensity and frequency, outcome measures, and alexia severity.

Delayed Stimulus-Specific Improvements in Discourse Following Anomia Treatment Using an Intentional Gesture

Purpose: In this study, the authors assessed how the addition of intentional left-hand gestures to an intensive treatment for anomia affects 2 types of discourse: picture description and responses to open-ended questions.Method: Fourteen people with aphasia completed treatment for anomia comprising 30 treatment sessions over 3 weeks.Seven subjects also incorporated intentional left-hand gestures into each treatment trial.Results: Both groups demonstrated significant changes in trained items and improved naming of untrained items but no change in Western Aphasia Battery—Aphasia Quotient(WAB–AQ; Kertesz, 1982) scores. Changes in discourse were limited to the 3-month follow-up assessment. Several discourse measures showed significant improvements in the picture description task and declines during question responses. Additionally, the gesture group produced more words at each assessment, whereas the no gesture group produced fewer words at each assessment. These patterns led to improvements in picture descriptions and minimal declines in question responses in the gesture group. In contrast, the no gesture group showed minimal improvements in picture descriptions and production declines in question responses relative to pretreatment levels.Conclusion: The intensive treatment protocol is a successful method for improving picture naming even of untrained items.Further, the authors conclude that the intentional left-hand gesture contributed significantly to the generalization of treatment to discourse.

An analysis of aphasic naming errors as an indicator of improved linguistic processing following phonomotor treatment

PURPOSE

The aim of this study was to investigate the influence of phonomotor treatment on the types of errors produced during a confrontation naming task for people with aphasia (PWA).

METHOD

Ten PWA received 60&emsp14;hr of phonomotor treatment across 6 weeks. Confrontation naming abilities were measured before and after treatment, and responses were coded as correct or incorrect. Incorrect responses were coded for error type. Paired t tests comparing pre-, post- and 3 months posttreatment naming accuracy and error type were performed.

RESULTS

Group data showed that naming accuracy on trained items improved significantly immediately post treatment, and gains were maintained 3 months later. Naming accuracy on untrained items did not show significant improvement immediately post treatment or 3 months later. Results of error type analysis were not significant. However, a decrease in omission errors and an increase in mixed errors were noted immediately post treatment for naming of untrained items.

CONCLUSION

Results suggest that intensive phonomotor treatment improved lexical-retrieval abilities and may have triggered a shift in linguistic processing, as indicated by a decrease in omission errors on trained items and an increase in mixed errors on untrained items.

Speech entrainment enables patients with Broca's aphasia to produce fluent speech

A distinguishing feature of Broca's aphasia is non-fluent halting speech typically involving one to three words per utterance. Yet, despite such profound impairments, some patients can mimic audio-visual speech stimuli enabling them to produce fluent speech in real time. We call this effect 'speech entrainment' and reveal its neural mechanism as well as explore its usefulness as a treatment for speech production in Broca's aphasia. In Experiment 1, 13 patients with Broca's aphasia were tested in three conditions: (i) speech entrainment with audio-visual feedback where they attempted to mimic a speaker whose mouth was seen on an iPod screen; (ii) speech entrainment with audio-only feedback where patients mimicked heard speech; and (iii) spontaneous speech where patients spoke freely about assigned topics. The patients produced a greater variety of words using audio-visual feedback compared with audio-only feedback and spontaneous speech. No difference was found between audio-only feedback and spontaneous speech. In Experiment 2, 10 of the 13 patients included in Experiment 1 and 20 control subjects underwent functional magnetic resonance imaging to determine the neural mechanism that supports speech entrainment. Group results with patients and controls revealed greater bilateral cortical activation for speech produced during speech entrainment compared with spontaneous speech at the junction of the anterior insula and Brodmann area 47, in Brodmann area 37, and unilaterally in the left middle temporal gyrus and the dorsal portion of Broca's area. Probabilistic white matter tracts constructed for these regions in the normal subjects revealed a structural network connected via the corpus callosum and ventral fibres through the extreme capsule. Unilateral areas were connected via the arcuate fasciculus. In Experiment 3, all patients included in Experiment 1 participated in a 6-week treatment phase using speech entrainment to improve speech production. Behavioural and functional magnetic resonance imaging data were collected before and after the treatment phase. Patients were able to produce a greater variety of words with and without speech entrainment at 1 and 6 weeks after training. Treatment-related decrease in cortical activation associated with speech entrainment was found in areas of the left posterior-inferior parietal lobe. We conclude that speech entrainment allows patients with Broca's aphasia to double their speech output compared with spontaneous speech. Neuroimaging results suggest that speech entrainment allows patients to produce fluent speech by providing an external gating mechanism that yokes a ventral language network that encodes conceptual aspects of speech. Preliminary results suggest that training with speech entrainment improves speech production in Broca's aphasia providing a potential therapeutic method for a disorder that has been shown to be particularly resistant to treatment.

Rehabilitation of language in expressive aphasias: a literature review

Objective

This paper reviews the methodological characteristics of studies on rehabilitation of expressive aphasia, describing the techniques of rehabilitation used.

Methods

The databases Medline, Science Direct and PubMed were searched for relevant articles (January 1999 to December 2011) using the keywords Expressive / Broca / Nonfluent Aphasia, combined with Language or Speech Rehabilitation / Therapy / Intervention.

Results

A total of 56 articles were retrieved describing rehabilitation techniques, including 22 with a focus on lexical processing, 18 on syntax stimulation, seven with the aim of developing speech and nine with multiple foci.

Conclusion

A variety of techniques and theoretical approaches are available, highlighting the heterogeneity of research in this area. This diversity can be justified by the uniqueness of patients' language deficits, making it difficult to generalize. In addition, there is a need to combine the formal measures of tests with measures of pragmatic and social skills of communication to determine the effect of rehabilitation on the patient's daily life.

Can tDCS enhance treatment of aphasia after stroke?

BACKGROUND: Recent advances in the application of transcranial direct current stimulation (tDCS) in healthy populations have led to the exploration of the technique as an adjuvant method to traditional speech therapies in patients with post-stroke aphasia. AIMS: THE PURPOSE OF THE REVIEW IS: (i) to review the features of tDCS that make it an attractive tool for research and potential future use in clinical contexts; (ii) to describe recent studies exploring the facilitation of language performance using tDCS in post-stroke aphasia; (iii) to explore methodological considerations of tDCS that may be key to understanding tDCS in treatment of aphasia post stroke; and (iv) to highlight several caveats and outstanding questions that need to be addressed in future work. MAIN CONTRIBUTION: This review aims to highlight our current understanding of the methodological and theoretical issues surrounding the use of tDCS as an adjuvant tool in the treatment of language difficulties after stroke. CONCLUSIONS: Preliminary evidence shows that tDCS may be a useful tool to complement treatment of aphasia, particularly for speech production in chronic stroke patients. To build on this exciting work, further systematic research is needed to understand the mechanisms of tDCS-induced effects, its application to current models of aphasia recovery, and the complex interactions between different stimulation parameters and language rehabilitation techniques. The potential of tDCS is to optimise language rehabilitation techniques and promote long-term recovery of language. A stimulating future for aphasia rehabilitation!

Thinking About Better Speech: Mental Practice for Stroke-Induced Motor Speech Impairments

BACKGROUND: Mental practice (MP) is a mind-body technique in which physical movements are cognitively rehearsed. It has shown efficacy in reducing the severity of a number of neurological impairments. AIMS: In the present review, we highlight recent developments in MP research, and the basis for MP use after stroke-induced motor speech disorders. MAIN CONTRIBUTION: In this review, we: (a) propose a novel conceptual model regarding the development of learned nonuse in people with motor speech impairments; (b) review the rationale and efficacy of MP for reducing the severity of stroke-induced impairments; (c) review evidence demonstrating muscular and neural activations during and following MP use; (d) review evidence showing that MP increases skill acquisition, use, and function in stroke; (e) review literature regarding neuroplasticity after stroke, including MP-induced neuroplasticity and the neural substrates underlying motor and language reacquisition; and (f) based on the above, review the rationale and clinical application of MP for stroke-induced motor speech impairments. CONCLUSIONS: Support for MP use includes decades of MP neurobiological and behavioral efficacy data in a number of populations. Most recently, these data have expanded to the application of MP in neurological populations. Given increasingly demanding managed care environments, efficacious strategies that can be easily administered are needed. We also encounter clinicians who aspire to use MP, but their protocols do not contain several of the elements shown to be fundamental to effective MP implementation. Given shortfalls of some conventional aphasia and motor speech rehabilitative techniques, and uncertainty regarding optimal MP implementation, this paper introduces the neurophysiologic bases for MP, the evidence for MP use in stroke rehabilitation, and discusses its applications and considerations in patients with stroke-induced motor speech impairments.