Improving Production of Treated and Untreated Verbs in Aphasia: A Meta-Analysis

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.

Treatment of verb tense inflection and sentence production in Persian individuals with agrammatism

Production of verb morphology, especially tense inflection, is usually impaired in individuals with agrammatism. There have been relatively few studies on treatment of verb tense inflection in agrammatic aphasia. In this study we adapted ACTION (a linguistically motivated treatment) to Persian language, to treat the production of regular and irregular verbs separately in sentence context. A single-subject multiple-baseline across behaviors design was used to establish the treatment effect. Using a non-probable convenience sampling, four Persian agrammatic patients with Broca's aphasia resulting from cerebrovascular accident (CVA) were recruited for this study. Two participants received treatment first for regular verbs (Phase 1, 4 weeks), and then for irregular verbs (Phase 2, 4 weeks). The other two participants received treatment in reverse order. In the final phase of treatment (Phase 3, 4 weeks), all 4 participants underwent a sentence construction treatment. All participants showed improvement in the production of trained tenses. Treatment also generalized to production of untrained regular verbs while generalization to irregular verbs was modest. Furthermore, improvement was found on narrative scores (e.g. MLU) after treatment. These findings suggest that Persian individuals with agrammatism could be trained to correctly apply temporal information to verb inflection in elicited speech.

Applying Appraisal Tools in Aphasia Systematic Reviews: A Tutorial

PURPOSE

A systematic review (SR) represents a rigorous process of identifying and summarizing current research to answer specific clinical questions. Not all SRs present high-quality information, because they do not adhere to established standards of conduct or reporting. This tutorial aims to (a) describe two tools developed in epidemiology for reporting (PRISMA 2020; Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and appraising (AMSTAR 2; A MeaSurement Tool to Assess Systematic Reviews) SRs and (b) exemplify the use of AMSTAR 2. First, we describe the intents of PRISMA 2020 and AMSTAR 2 and compare the items on each checklist. Next, we apply the AMSTAR 2 list of domains to critically appraise methodological quality in two randomly selected SRs, which describe aphasia treatment. Appraisal results are reported, including the AMSTAR 2 ratings for overall confidence in the results of each review. For each SR, the overall rating was critically low, indicating that within the seven critical domains of AMSTAR 2, the SR had more than one critical weakness.

CONCLUSIONS

While PRISMA 2020 is a tool to guide preparation of SRs, to examine SR quality, the AMSTAR 2 is the tool of choice. Applied to two current aphasia treatment SRs, the AMSTAR 2 demonstrates that although both SRs were thorough, thoughtful summaries of a body of aphasia treatment literature, they did not achieve high ratings for methodological quality. Clinicians reading SRs are advised to familiarize themselves with quality assessment tools to assure that an SR meets expected criteria to document internal and external validity of the SR process, so resulting findings can be confidently applied for patients with aphasia.

Growing Random Forests reveals that exposure and proficiency best account for individual variability in L2 (and L1) brain potentials for syntax and semantics

Late second language (L2) learners report difficulties in specific linguistic areas such as syntactic processing, presumably because brain plasticity declines with age (following the critical period hypothesis). While there is also evidence that L2 learners can achieve native-like online-processing with sufficient proficiency (following the convergence hypothesis), considering multiple mediating factors and their impact on language processing has proven challenging. We recorded EEG while native (n = 36) and L2-speakers of French (n = 40) read sentences that were either well-formed or contained a syntactic-category error. a lexical-semantic anomaly, or both. Consistent with the critical period hypothesis, group differences revealed that while native speakers elicited a biphasic N400-P600 in response to ungrammatical sentences, L2 learners as a group only elicited an N400. However, individual data modeling using a Random Forests approach revealed that language exposure and proficiency are the most reliable predictors in explaining ERP responses, with N400 and P600 effects becoming larger as exposure to French as well as proficiency increased, as predicted by the convergence hypothesis.

A Systematically Conducted Scoping Review of the Evidence and Fidelity of Treatments for Verb Deficits in Aphasia: Verb-in-Isolation Treatments

Purpose Aphasia research demonstrates increasing interest in the treatment of verb retrieval deficits. This systematically conducted scoping review reports on the level and fidelity of the current evidence for verb treatments; on its effectiveness regarding the production of trained and untrained verbs, functional communication, sentences, and discourse; and on the potential active ingredients. Recommendations to guide clinical decision making and future research are made. Method The computerized database search included studies from January 1980 to September 2018. The level of evidence of each study was documented, as was fidelity in terms of treatment delivery, enactment, and receipt. Studies were also categorized according to the treatment methods used. Results Thirty-seven studies were accepted into the review, and all but 1 constituted a low level of evidence. Thirty-three studies (89%) described treatment in sufficient detail to allow replication, dosage was poorly reported, and the fidelity of treatment was rarely assessed. The most commonly reported treatment techniques were phonological and semantic cueing in 25 (67.5%) and 20 (54%) studies, respectively. Retrieval of trained verbs improved for 80% of participants, and improvements generalized to untrained verbs for 15% of participants. There was not sufficient detail to evaluate the impact of treatment on sentence production, functional communication, and discourse. Conclusions The evidence for verb treatments is predominantly of a low level. There are encouraging findings in terms of treatments being replicable; however, this is tempered by poor monitoring of treatment fidelity. The quality of verb treatment research would be improved by researchers reaching consensus regarding outcome measures (including generalization to, e.g., sentences and discourse) by manualizing treatment to facilitate implementation and exploring the opinions of participants. Finally, while treatment is largely effective in improving production of trained verbs, lack of generalization to untrained items leads to the recommendation that personally relevant verbs are prioritized.

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.

Cognitive and language performance predicts effects of spelling intervention and tDCS in Primary Progressive Aphasia

Predictors of treatment effects allow individual tailoring of treatment characteristics, thereby saving resources and optimizing outcomes. Electrical stimulation coupled with language intervention has shown promising results in improving language performance in individuals with Primary Progressive Aphasia (PPA). The current study aimed to identify language and cognitive variables associated with response to therapy consisting of language intervention combined with transcranial direct current stimulation (tDCS). Forty individuals with PPA received written naming/spelling intervention combined with anodal tDCS or Sham, using a between-subjects, randomized design, with intervention delivered over a period of 3 weeks. Participants were assessed using a battery of neuropsychological tests before and after each phase. We measured letter accuracy during spelling of trained and untrained words, before, immediately after, 2 weeks, and 2 months after therapy. We used step-wise regression methods to identify variables amongst the neuropsychological measures and experimental factors that were significantly associated with therapy outcomes at each time-point. For trained words, improvement was related to pre-therapy scores, in RAVLT (5 trials sum), pseudoword spelling, object naming, digit span backward, spatial span backward and years post symptom onset. Regarding generalization to untrained words, improvement in spelling was associated with pseudoword spelling, RAVLT proactive interference, RAVLT immediate recall. Generalization effects were larger under tDCS compared to Sham at the 2-month post training measurement. We conclude that, for trained words, patients who improve the most are those who retain for longer language skills such as sublexical spelling processes (phoneme-to-grapheme correspondences) and word retrieval, and other cognitive functions such as executive functions and working memory, and those who have a better learning capacity. Generalization to untrained words occurs through improvement in knowledge of phoneme-to-grapheme correspondences. Furthermore, tDCS enhances the generalizability and duration of therapy effects.

'What's cooking?' A comparison of an activity-oriented and a table-top programme of therapy on the language performance of people with aphasia

BACKGROUND

Many people with aphasia have word-finding difficulties, with some showing particular difficulties with verbs. Picture-naming therapy is often used to improve naming, but gains are usually limited to therapy items and do not transfer to conversation. Therapy where words are produced in sentences and in real-life activities may be more effective.

AIMS

The current pilot study investigated whether an activity-oriented therapy approach would be accepted and viable if implemented in a community setting, and whether communicating whilst cooking was more beneficial than using paper-based activities. If successful, it would be expected that verb production would improve in structured and unstructured tasks in both naming and narrative tasks.

METHODS & PROCEDURES

The study employed a case-series repeated-measures design, with testing of treated and control items. Seven adults with anomia participated, although only five completed the full programme. Participants were divided into two groups and each group completed both treatments, but in different orders. Each treatment was employed for six 2-h sessions over a 3-week period.

OUTCOMES & RESULTS

Naming of both treated and untreated verbs showed a statistically significant improvement following both treatments and this continued into the maintenance phase. There was a numerical but not statistically significant gain in the variety of verbs used in spoken narratives. Participants predominantly chose positive terms to describe their experience of the programme, but did not prefer one therapy over the other.

CONCLUSIONS & IMPLICATIONS

Preliminary findings suggest that an activity-oriented therapy approach, whether it involves carrying out tasks or paper-based activities, can result in clinically meaningful improvements for people with chronic aphasia. Further research using a randomized control trial is required to determine whether cooking therapy alone is effective.

Predicting the sources of impaired wh-question comprehension in non-fluent aphasia: A cross-linguistic machine learning study on Turkish and German

This study investigates the comprehension of wh-questions in individuals with aphasia (IWA) speaking Turkish, a non-wh-movement language, and German, a wh-movement language. We examined six German-speaking and 11 Turkish-speaking IWA using picture-pointing tasks. Findings from our experiments show that the Turkish IWA responded more accurately to both object who and object which questions than to subject questions, while the German IWA performed better for subject which questions than in all other conditions. Using random forest models, a machine learning technique used in tree-structured classification, on the individual data revealed that both the Turkish and German IWA's response accuracy is largely predicted by the presence of overt and unambiguous case marking. We discuss our results with regard to different theoretical approaches to the comprehension of wh-questions in aphasia.