Evaluating Cognitive-Linguistic Approaches to Interventions for Aphasia Within the Rehabilitation Treatment Specification System

Anomia prehabilitation in temporal lobe epilepsy surgery: A pilot study

OBJECTIVE

An emerging approach in surgery is to propose prehabilitation programs to strengthen the patient's functional abilities before surgical interventions, thus helping them cope better with its consequences. In drug-resistant language-dominant temporal lobe epilepsy (LdTLE), surgical treatment carries a risk of increasing cognitive deficits, notably word-finding difficulties (anomia) and verbal memory difficulties that negatively impact personal, social, and occupational activities. In this study, we invited 15 LdTLE patients to enroll in a speech and language prehabilitation program adapted to the specifics of their difficulties, organized daily during the preoperative period.

METHODS

Naming performance (for trained and untrained words) was studied twice before prehabilitation, during prehabilitation, and 1 week and 6 months after surgery. Results were analyzed using a generalized linear mixed effects model.

RESULTS

We found a significant effect of prehabilitation on trained items before surgery. Postoperatively, trained items showed a slight and nonsignificant performance increase compared to baseline, whereas untrained items showed a significant decline in the same comparison.

SIGNIFICANCE

We conclude that trained words were better protected from postsurgical decline than untrained words. Our research can contribute to patient support during surgical decision-making; ultimately, prehabilitation might be considered as part of individualized care. These encouraging results lay the groundwork for more detailed or powerful examinations of the protective effect of prehabilitation on language skills.

The Role of Enablement Theory in Rehabilitation Practice, Education, and Research

Enablement theory refers to the theoretical framework that describes the interrelationships among different areas of functioning, such as those illustrated by the International Classification of Functioning, Disability, and Health (ICF). Enablement theory is necessary to explain causal relationships and predictions of how changes in one aspect of function impact distal outcomes. This is in contrast with treatment theory, which describes how the active ingredient(s) of an intervention directly impact a measurable target. Enablement theory helps clinicians articulate their rehabilitation treatment plans by identifying the underlying targets necessary to achieve a patient's desired outcomes and monitor the response to treatment. In this manner, enablement theory can also support the education of novice and experienced clinicians and/or trainees in their clinical reasoning process. Enablement theory helps researchers articulate the relationships they hypothesize between the aspects of function they seek to change with an intervention and the immediate and distal outcomes of that intervention. Researchers can then design the rehabilitation intervention and identify key outcome measures to rigorously test their conceptual framework, including the important mediators of the intervention's effects, and aid in the interpretation of study results. The use of enablement models has not been well-described in the rehabilitation literature, and formal research focused on understanding the nature and strength of the relationships within these enablement models is necessary to advance the field of rehabilitation. We discuss how enablement theory contributes to our understanding of rehabilitation interventions in the context of clinical practice, health professions education, and rehabilitation research.

Implicit structural priming as a treatment component for aphasia: Specifying essential learning conditions

This study applies implicit structural priming as a novel treatment for sentence production in persons with aphasia (PWA), investigating the learning mechanism(s) that drive robust and enduring recovery. Sixteen PWA and 16 controls completed baseline, three training sessions, and 1-day and 1-week post-testing. Each participant received both alternating and single structure prime training conditions to test error-based versus repeated activation-based learning. Both groups showed significantly improved production and maintenance of trained and untrained target sentences in both training conditions. While controls showed greater gains following alternating prime structure training, single prime structure training resulted in greater improvements for PWA. These results suggest that structural priming is an effective training for aphasia. Additionally, to the extent that the different priming conditions reflected different mechanisms underlying the learning and access of impaired structure, increased base-level activation of target syntactic structure supports learning of grammatical encoding in aphasia more effectively than processing prime sentences with competing syntactic structures.

Structural Priming for Sentence Production in Aphasia: What Does Oral Repetition Do?

PURPOSE

Structural priming-speakers' unconscious tendency to reuse previously encountered sentence structures (primes) in future production-facilitates access and learning of grammatical representations in persons with aphasia (PWAs). However, it remains unclear which components of structural priming tasks are essential to consistent and lasting effects, a discovery critical for cost-effective clinical translation of research. We examined the effects of orally repeating versus listening to primes on immediate and lasting sentence production in PWAs and controls.

METHOD

In a collaborative priming task, participants took turns with the experimenter, describing transitive and dative event pictures. One group of PWAs and controls listened to the experimenter's descriptions (primes) before they described their own picture, whereas the other group orally repeated their interlocutor's prime sentences before the target picture descriptions. In Experiment 1, the target picture description was elicited immediately after the prime (0-lag, immediate priming). In Experiment 2, two filler trials (2-lag) intervened between prime and target, examining longer term priming.

RESULTS

At both immediate and longer term priming, significant priming effects were observed in both groups, as indicated by increased productions of passives following passive versus active primes and increased productions of double-object dative sentences following double-object than prepositional object dative prime sentences. However, orally repeating prime sentences did not reliably and consistently enhance the magnitude of priming effects across lags and groups. Additionally, PWAs' repetition abilities did not result in higher degrees of priming effects.

CONCLUSION

These findings suggest that opportunities for processing syntactic representations that shared between prior (prime) and current (target) utterances is a rather essential ingredient for positive structural priming in PWAs, while repeating prime sentences is an optional ingredient that can be removed or modified.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28291949.

Rehabilitation of post-stroke aphasia by a single protocol targeting phonological, lexical, and semantic deficits with speech output tasks: a randomized controlled trial

BACKGROUND

The defective spoken output of persons with aphasia has anomia as a main clinical manifestation. Improving anomia is therefore a main goal of any language treatment.

AIM

This study assessed the effectiveness of a novel, 2-week, rehabilitation protocol (PHOLEXSEM), focused on PHonological, SEmantic, and LExical deficits, aiming at improving lexical retrieval, and, generally, spoken output.

DESIGN

A prospective, randomized controlled trial.

SETTING

In-patient and out-patient population of the Neurorehabilitation Unit of the Istituto Auxologico Italiano IRCCS, Milan, Italy.

POPULATION

The sample comprised 44 adults with aphasia due to left brain damage; 22 of them were assigned to the experimental (PHOLEXSEM) group, whereas 22 were assigned to the control group that received the Promoting Aphasics Communicative Effectiveness (PACE) protocol.

METHODS

All participants were treated 30-min daily for two weeks. The PHOLEXSEM training included 3 sets of exercises: 1) non-word, word, and phrase repetition; 2) semantic feature analysis by naming; 3) phonemic, semantic, and verb recall. Treatment effects were evaluated with tasks and items different from those used for training, to assess generalization effects.

RESULTS

After the PHOLEXSEM treatment, repetition, naming, lexical retrieval and sentence comprehension improved more than in the control - PACE - group, with gains generalizing to non-trained items. These improvements were independent of aphasia chronicity and only marginally influenced by demographic factors.

CONCLUSIONS

The 2-week PHOLEXSEM training, by targeting spoken output, ameliorates different aspects of aphasia, ranging from speech production (i.e., phonology and lexical retrieval) to comprehension.

CLINICAL REHABILITATION IMPACT

The PHOLEXSEM training is a useful and easy-to-administer intervention to improve post-stroke language deficits in adults of different ages, levels of education, duration, type, and severity of aphasia.

The Active Ingredients of Semantic Naming Treatment: Evidence From Mandarin-English Bilingual Adults With Aphasia

PURPOSE

Following the Rehabilitation Treatment Specification System (RTSS) framework, the current study investigated the active ingredients in the modified semantic feature analysis (mSFA) targeting either noun or verb retrieval in Mandarin-English bilingual adults with aphasia (BWA).

METHOD

Twelve Mandarin-English BWA completed mSFA treatment for nouns and verbs. Eight of them completed both noun and verb treatment, while four completed either type of treatment. Performance in each step was scored and analyzed using mixed-effects modeling. Then, regression was performed to estimate the effect of treatment performance on the accuracy of naming probes for trained and semantically related items in both treated and untreated languages.

RESULTS

Participants demonstrated significant improvements in all treatment steps during both noun and verb treatment, yet the effect varied depending on the trained word category and treatment language. Moreover, all treatment components contributed significantly to the treatment outcomes. Better treatment performance in spontaneous naming was significantly associated with improved naming accuracy of the trained items in noun mSFA, while better treatment performance in spontaneous naming, feature analysis, and sentence production was significantly associated with enhanced naming of the semantically related untrained items in noun mSFA. Importantly, performance in all treatment steps of both noun and verb mSFA significantly predicted naming accuracy in the untreated language.

CONCLUSION

Findings provided strong evidence of the potential active ingredients of semantic-based naming therapy in Mandarin-English BWA and highlighted the importance of examining treatment ingredients within the RTSS framework.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28003292.

Using and Modifying Standardized Restorative Treatments in Aphasia: Clinician Perspectives

PURPOSE

Aphasia treatment should be individualized, so clinicians are likely modifying established treatment paradigms to fit client needs. Little extant research describes which treatment protocols clinicians modify, how and why they modify their treatments, and what sources they use to guide their modifications. The purpose of this study was to gain insights into these issues.

METHOD

A Qualtrics survey was distributed through speech-language pathology-related professional and social media networks from January through June 2023. Forty-seven speech-language pathologists provided basic information on assessment and treatment approaches that they use, and 32 respondents provided detailed responses regarding their current treatment practices.

RESULTS

The two restitutive aphasia treatments clinicians reported using most often were Semantic Feature Analysis and Verb Network Strengthening Treatment. The reasons for using these two treatments were that they are easy to administer, patients enjoy them, and they are perceived to be effective. Most clinicians reported that they often modify aphasia treatment protocols for a variety of reasons. These included matching patients' linguistic profiles by changing stimuli or the presentation modality as well as meeting time constraints and productivity standards. Respondents reported that they mostly rely on their personal experience, suggestions from colleagues, and linguistic theory to guide their modifications.

CONCLUSIONS

Clinicians often modify standardized treatments to balance their patients' needs and the demands of their settings and typically rely on personal experience to do so. In the future, more clinician-researcher partnerships and investigations of active treatment ingredients are needed to support clinicians in making efficient and effective treatment modifications.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.27703662.

Self-Improved Language Production in Nonfluent Aphasia Through Automated Recursive Self-Feedback

BACKGROUND

Persons with nonfluent aphasia (PWNA) use feedback from external agents (e.g., speech-language pathologists) and self-feedback to improve their language production. The extent to which PWNA can improve their language production using their self-feedback alone is underexplored. In a proof-of-concept study, we developed an automated recursive self-feedback procedure to demonstrate the extent to which two PWNA who used self-feedback alone improved their production of sentences from trained and untrained scripts. In the current study, we use the Rehabilitation Response Specification System as a framework to replicate our initial findings.

METHOD

We tested the effects of two treatments: script production with recursive self-feedback and script production with external feedback in four persons with chronic nonfluent aphasia. We compared the effects of treatment by measuring percent script produced, speaking rate, and speech initiation latency of trained and untrained scripts. The participants received the treatments remotely through mini tablets using two versions of a mobile app we developed. All the participants received each treatment intensively for 14 sessions across 2-3 weeks. We estimated clinical improvements of production of sentences from trained and untrained scripts through nonoverlap of all pairs analysis of performance pretreatment and posttreatment.

RESULTS

Both treatments improved PWNA's language production. Recursive self-feedback improved speaking rate and speech initiation latency, which generalized to untrained scripts in all participants. External feedback treatment did not generalize to improvement in speaking rate in two participants.

CONCLUSIONS

Our findings confirm our initial evidence that PWNA can self-improve their sentence production from scripts through recursive self-feedback. This novel procedure enables PWNA to autonomously enhance their language production over time. Given the evidence and the mechanics of the procedure, we propose that its utility is not constrained by linguistic idiosyncrasies across cultures. Consequently, it has the potential to bypass linguistic barriers to aphasia care.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.27007060.

Comparative Efficacy of Cognitive Training for Post-Stroke Aphasia: A Systematic Review and Network Meta-Analysis

BACKGROUND

Although cognitive training has shown potential for treating post-stroke aphasia (PSA), its efficacy varies across studies, and the optimal training approaches remain unclear.

OBJECTIVE

To evaluate and compare the effects of distinct cognitive training interventions, either combined with or independent of speech and language therapy (SLT), on language function in individuals with PSA.

METHODS

A systematic search encompassing PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang, VIP, and Chinese Biomedical Databases was conducted for randomized controlled trials (RCTs). A network meta-analysis evaluated interventions, including computer-assisted cognitive training (CCT), conventional cognitive training (CT), virtual reality (VR)-based cognitive training (vrCT), telerehabilitation computer-assisted cognitive training (tCCT), working memory (WM) training, and attention training (AT).

RESULTS

Eleven RCTs comprising 501 participants were included. Individuals with PSA who underwent combined WM training with SLT led to significantly enhanced Western Aphasia Battery (WAB) Aphasia Quotient (AQ), as well as in spontaneous speech, auditory comprehension, repetition, and naming, compared to those receiving SLT alone. This combination was more effective than both CCT with SLT and tCCT with SLT in improving WAB AQ. Similarly, it outperformed both CCT with SLT and vrCT with SLT in enhancing WAB spontaneous speech. Additionally, both AT and CT combined with SLT were more effective than SLT alone in enhancing WAB spontaneous speech. Specifically, AT combined with SLT proved more effective than vrCT with SLT in this area. Moreover, vrCT combined with SLT significantly improved auditory comprehension compared with SLT alone.

CONCLUSIONS

Combining WM training and SLT and integrating vrCT with SLT both significantly enhance language function in individuals with PSA, compared with SLT alone. Our findings advocate for the use of these cognitive training approaches as promising strategies for language rehabilitation in this population. PROSPERO registration number: CRD42023462361.

The Flu-ID: A New Evidence-Based Method of Assessing Fluency in Aphasia

PURPOSE

Assessing fluency in aphasia is diagnostically important for determining aphasia type and severity and therapeutically important for determining appropriate treatment targets. However, wide variability in the measures and criteria used to assess fluency, as revealed by a recent survey of clinicians (Gordon & Clough, 2022), results in poor reliability. Furthermore, poor specificity in many fluency measures makes it difficult to identify the underlying impairments. Here, we introduce the Flu-ID Aphasia, an evidence-based tool that provides a more informative method of assessing fluency by capturing the range of behaviors that can affect the flow of speech in aphasia.

METHOD

The development of the Flu-ID was based on prior evidence about factors underlying fluency (Clough & Gordon, 2020; Gordon & Clough, 2020) and clinical perceptions about the measurement of fluency (Gordon & Clough, 2022). Clinical utility is maximized by automated counting of fluency behaviors in an Excel template. Reliability is maximized by outlining thorough guidelines for transcription and coding. Eighteen narrative samples representing a range of fluency were coded independently by the authors to examine the Flu-ID's utility, reliability, and validity.

RESULTS

Overall reliability was very good, with point-to-point agreement of 86% between coders. Ten of the 12 dimensions showed good to excellent reliability. Validity analyses indicated that Flu-ID scores were similar to clinician ratings on some dimensions, but differed on others. Possible reasons and implications of the discrepancies are discussed, along with opportunities for improvement.

CONCLUSIONS

The Flu-ID assesses fluency in aphasia using a consistent and comprehensive set of measures and semi-automated procedures to generate individual fluency profiles. The profiles generated in the current study illustrate how similar ratings of fluency can arise from different underlying impairments. Supplemental materials include an analysis template, extensive guidelines for transcription and coding, a completed sample, and a quick reference guide.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.27078199.

Barriers and facilitators to outcome measurement and treatment practices in aphasia rehabilitation in the USA: a mixed methods approach using the Theoretical Domains Framework

PURPOSE

To identify clinician-perceived barriers and facilitators to the delivery of outcome measurement and evidence-based treatment practices and integration of these practices in aphasia rehabilitation.

MATERIALS AND METHODS

Using a convergent mixed methods design, aphasia clinicians (n = 87) across care settings in the United States completed an online survey designed within the Theoretical Domains Framework (TDF). Participants responded to open-ended questions and rated Likert scale statements. Qualitative data were analyzed using content analysis and quantitative data were summarized using descriptive statistics.

RESULTS

Factors related to the TDF domain of "environmental context and resources" (priority and productivity demands; characteristics of resources) were cited as primary barriers in 70% of qualitative responses for both outcome and treatment practices and were consistent with Likert rating statements. Facilitators were associated with TDF domains of "memory, attention, decision-making" (decision-making processes), "knowledge" (awareness of evidence) and "social influences" (client and caregiver preferences).

CONCLUSIONS

Organizational-level factors and the misalignment of the research evidence with clinical needs are barriers to delivering evidence-based care in aphasia rehabilitation. Theoretically informed strategies such as establishing organizational infrastructure for practice change, developing clinically relevant evidence through research-practice partnerships, and implementing algorithms to support clinical decision-making can address barriers and leverage facilitators.

Incorporating Metacognitive Strategy Training Into Semantic Treatment Promotes Restitutive and Substitutive Gains in Naming: A Single-Subject Investigation

PURPOSE

This study tested the effectiveness of a modified semantic feature analysis (SFA) treatment protocol that incorporated metacognitive strategy training (MST). Regarding its restitutive component, SFA most reliably results in improved word retrieval for treated items and untreated, semantically related items, but evidence of response generalization is often small/inconsistent. Regarding its substitutive component, SFA is thought to facilitate successful communication via habituation of the SFA circumlocution strategy. However, repeated practice with SFA's strategy in the absence of direct MST may not result in independent strategy use and/or generalization. Furthermore, people with aphasia's independent use of the SFA strategy in moments of anomia is presently underreported. To address these limitations, we incorporated MST into SFA and directly measured substitutive outcomes.

METHOD

Four people with aphasia participated in 24 treatment sessions of SFA + MST in a single-subject, A-B experimental design with repeated measurements. We measured word retrieval accuracy, strategy use, and explicit strategy knowledge. We calculated effect sizes to measure changes in word retrieval accuracy and strategy use and used visual inspection to assess gains in explicit strategy knowledge from pre- to posttreatment and retention.

RESULTS

Participants achieved marginally small to medium effects in word retrieval accuracy for treated; untreated, semantically related; and untreated, semantically unrelated items and marginally small to large effects in independent strategy use. Explicit strategy knowledge was variable.

CONCLUSIONS

Across participants, SFA + MST yielded positive changes in word retrieval accuracy or strategy use, or both. Positive changes in word retrieval accuracy were comparable to other SFA studies. Positive changes in strategy use demonstrate preliminary evidence of this treatment's ability to yield restitutive and substitutive gains. Overall, this study offers preliminary evidence of SFA + MST's effectiveness and highlights the importance of directly measuring SFA's substitutive outcomes, which showed that people with aphasia can respond to this treatment in multiple successful ways-not just improved target word production.

Comparator Groups in ICU-Based Studies of Physical Rehabilitation: A Scoping Review of 125 Studies

To characterize comparator groups (CGs) in ICU-based studies of physical rehabilitation (PR), including the type, content, and reporting.

DATA SOURCES

We followed a five-stage scoping review methodology, searching five databases from inception to June 30, 2022. Study selection and data extraction were completed independently, in duplicate.

STUDY SELECTION

We screened studies by title and abstract, then full-text. We included prospective studies with greater than or equal to two arms enrolling mechanically ventilated adults (≥ 18 yr), with any planned PR intervention initiated in the ICU.

DATA EXTRACTION

We conducted a quantitative content analysis of authors' description of CG type and content. We categorized similar CG types (e.g., usual care), classified content into unique activities (e.g., positioning), and summarized these data using counts (proportions). We assessed reporting using Consensus on Exercise Reporting Template (CERT; proportion of reported items/total applicable).

DATA SYNTHESIS

One hundred twenty-five studies were included, representing 127 CGs. PR was planned in 112 CGs (88.2%; 110 studies), representing four types: usual care (n = 81, 63.8%), alternative treatment than usual care (e.g., different from intervention; n = 18, 14.2%), alternative treatment plus usual care (n = 7, 5.5%), and sham (n = 6, 4.7%). Of 112 CGs with planned PR, 90 CGs (88 studies) reported 60 unique activities, most commonly passive range of motion (n = 47, 52.2%). The remaining 22 CGs (19.6%; 22 studies) reported vague descriptions. PR was not planned in 12 CGs (9.5%; 12 studies), and three CGs (2.4%; three studies) reported no details. Studies reported a median (Q1-Q3) of 46.6% (25.0-73.3%) CERT items. Overall, 20.0% of studies reported no detail to understand planned CG activities.

CONCLUSIONS

The most common type of CG was usual care. We identified heterogeneity in planned activities and CERT reporting deficiencies. Our results could help guide the selection, design, and reporting of CGs in future ICU-based PR studies.

Rehabilitation Treatment Specification System: Identifying Barriers, Facilitators, and Strategies for Implementation in Research, Education, and Clinical Care

OBJECTIVE

To explore rehabilitation professionals' experiences and perspectives of barriers and facilitators to implementing the Rehabilitation Treatment Specification System (RTSS) in research, education, and clinical care.

DESIGN

A cross-sectional survey with free text and binary responses was completed by rehabilitation professionals. Survey data were analyzed with a deductive approach of directed content analysis using 2 implementation science frameworks: Consolidated Framework for Implementation Research (CFIR) and the Expert Recommendations for Implementing Change (ERIC).

SETTING

Rehabilitation professionals across research, educational, and clinical settings.

PARTICIPANTS

One hundred and eleven rehabilitation professionals-including speech-language pathologists, occupational therapists, physical therapists, physicians, psychologists, researchers, and clinic directors-who explored possible uses or applications of the RTSS for clinical care, education, or research (N=111).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Frequency of reported CFIR barriers and facilitators, as well as keywords related to CFIR and ERIC constructs.

RESULTS

The barriers and facilitating strategies differed according to the end-users' intended use, that is, research, education, or clinical. Overall, the 4 most frequently encountered CFIR barriers were the RTSS's complexity, a lack of available RTSS resources, reduced access to knowledge and information about the RTSS, and limited knowledge and beliefs about the RTSS. The ERIC-CFIR matching tool identified 7 ERIC strategies to address these barriers, which include conducting educational meetings, developing and distributing educational materials, accessing new funding, capturing and sharing local knowledge, identifying and preparing champions, and promoting adaptability.

CONCLUSIONS

When attempting to use the RTSS, rehabilitation professionals commonly encountered barriers to understanding and skillfully using the framework. Theory-driven implementation strategies have been identified that have potential for addressing the RTSS's complexity and lack of educational and skill-building resources. Future work can develop the identified implementation strategies and evaluate their effects on RTSS implementation.

Errorless, Errorful, and Retrieval Practice for Naming Treatment in Aphasia: A Scoping Review of Learning Mechanisms and Treatment Ingredients

PURPOSE

Increasingly, mechanisms of learning are being considered during aphasia rehabilitation. Well-characterized learning mechanisms can inform "how" interventions should be administered to maximize the acquisition and retention of treatment gains. This systematic scoping review mapped hypothesized mechanisms of action (MoAs) and treatment ingredients in three learning-based approaches targeting naming in aphasia: errorless learning (ELess), errorful learning (EFul), and retrieval practice (RP). The rehabilitation treatment specification system was leveraged to describe available literature and identify knowledge gaps within a unified framework.

METHOD

PubMed and CINHAL were searched for studies that compared ELess, EFul, and/or RP for naming in aphasia. Independent reviewers extracted data on proposed MoAs, treatment ingredients, and outcomes.

RESULTS

Twelve studies compared ELess and EFul, six studies compared ELess and RP, and one study compared RP and EFul. Hebbian learning, gated Hebbian learning, effortful retrieval, and models of incremental learning via lexical access were proposed as MoAs. To maximize treatment outcomes within theorized MoAs, researchers manipulated study ingredients including cues, scheduling, and feedback. Outcomes in comparative effectiveness studies were examined to identify ingredients that may influence learning. Individual-level variables, such as cognitive and linguistic abilities, may affect treatment response; however, findings were inconsistent across studies.

CONCLUSIONS

Significant knowledge gaps were identified and include (a) which MoAs operate during ELess, EFul, and RP; (b) which ingredients are active and engage specific MoAs; and (c) how individual-level variables may drive treatment administration. Theory-driven research can support or refute MoAs and active ingredients enabling clinicians to modify treatments within theoretical frameworks.

Examining Dose Frameworks to Improve Aphasia Rehabilitation Research

The effect of treatment dose on recovery of post-stroke aphasia is not well understood. Inconsistent conceptualization, measurement, and reporting of the multiple dimensions of dose hinders efforts to evaluate dose-response relations in aphasia rehabilitation research. We review the state of dose conceptualization in aphasia rehabilitation and compare the applicability of 3 existing dose frameworks to aphasia rehabilitation research-the Frequency, Intensity, Time, and Type (FITT) principle, the Cumulative Intervention Intensity (CII) framework, and the Multidimensional Dose Articulation Framework (MDAF). The MDAF specifies dose in greater detail than the CII framework and the FITT principle. On this basis, we selected the MDAF to be applied to 3 diverse examples of aphasia rehabilitation research. We next critically examined applicability of the MDAF to aphasia rehabilitation research and identified the next steps needed to systematically conceptualize, measure, and report the multiple dimensions of dose, which together can progress understanding of the effect of treatment dose on outcomes for people with aphasia after stroke. Further consideration is required to enable application of this framework to aphasia interventions that focus on participation, personal, and environmental interventions and to understand how the construct of episode difficulty applies across therapeutic activities used in aphasia interventions.

Treatment of the Linguistic and Temporal Components of Lexical Activation to Improve Word Retrieval in Aphasia

Current approaches to treatments for word processing impairments in aphasia emphasize two components to target, the linguistic content, semantic or phonological representations of words, and the processing component, access to and retrieval of those representations. In this study, we explore these two components of a treatment to improve lexical activation that supports access and retrieval of word representations. Five people with aphasia participated. The treatment task was repetition of concrete word pairs after a 5-s response delay which was intended to provide practice in maintaining activation of the words for that 5-s period before reproducing them. Two of the five participants demonstrated a difficulty in maintaining activation of single words in repetition, with accuracy decreasing significantly after the 5-s interval. The treatment was applied to all participants, however, to determine if its benefit was specific to those with the activation maintenance impairment. Results confirmed that the activation maintenance treatment in the context of this repetition task led to more treatment gains for the two participants who demonstrated this specific impairment. They made gains on four of the nine measures compared to improvements on one to two measures for the other participants. A second question addressed in this study was the relative importance of the item component (linguistic content) of the treatment and the processing component, maintenance of activation. To that end, there were two conditions of treatment probes, (1) repeated content for all treatment, immediate post-treatment and 3-month maintenance probes and (2) novel content for probes in these three phases of treatment. Only one participant showed significant improvement in treatment when items were novel for all probes. We discuss the possibility that this outcome reflects a more specific deficit in the temporal processing component of lexical activation compared to the two other participants who showed better performance on probes with repeated items in treatment and post-treatment phases. Clinical implications of this study and directions of future research are discussed.