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.

Metacognitive Treatment in Acquired Brain Injury and Its Applicability to Aphasia: A Systematic Review.

Purpose: The purpose of this systematic review is to identify the utility of metacognitive therapeutic intervention for persons with acquired brain injury (ABI), with a focus on persons with aphasia. Methods: A search of six databases resulted in two hundred and sixty-six unique manuscripts relating to the explicit use of metacognitive treatment for people with ABI. Two independent reviewers rated abstracts for inclusion or exclusion of the study given predetermined criteria. Twenty-nine articles, five of which included people with aphasia, were selected for inclusion in this systematic review. SCED+ and PEDro+ rating scales were used to rate the methodological quality of each study. Results: Methodological quality of the 29 studies that met inclusion criteria ranged from weak to high quality studies. Three -hundred and sixty-nine individuals with ABI took part in the 29 studies. Varying treatment methods were employed. Outcome measures were inconsistent. Metacognitive treatment has been applied to people with aphasia with positive results, but efficacy of the treatment cannot yet be determined. Conclusions: Metacognitive therapeutic intervention tends to be effective for persons with acquired brain injury (ABI) despite variability between intervention designs and treatment outcomes across studies. Due to so few studies with participants with aphasia, we were unable to draw conclusions regarding the efficacy of metacognitive treatment for people with aphasia. Further research on the efficacy of metacognitive treatment for this population is warranted.

Evaluating the Accuracy of Self-Ratings of Language in Adults with Aphasia and Non-Brain Injured Adults: A Pilot Study.

Rating scales are frequently used in research and clinical practice with people with aphasia (PWA) to characterize communication in the home environment. However, it remains unclear whether responses provided on rating scales accurately reflect the communication that occurs. We aim to evaluate the accuracy of PWA's self-perceptions of verbal language use as measured by a rating scale and determine whether this accuracy is different from that of non-brain-injured (NBI) participants. Four PWA and four NBI participants completed a rating scale estimating their amount of verbal language production as compared with their communication partner. Audio recordings from participants' home environments were analyzed for proportion of words and conversational turns contributed by the participant, which were compared with rating scale estimates. Perceptions of verbal language output among both PWA and NBI participants showed variable accuracy, with discrepancies between estimates and objective data across both groups. The reliability of rating scales in quantifying language output appears questionable, suggesting they may not accurately represent naturalistic language environments of PWA. Additional research with larger sample sizes is warranted to investigate whether this trend is consistent across a larger population of individuals with aphasia.

The relationship between entrainment dynamics and reading fluency assessed by sensorimotor perturbation.

A consistent relationship has been found between rhythmic processing and reading skills. Impairment of the ability to entrain movements to an auditory rhythm in clinical populations with language-related deficits, such as children with developmental dyslexia, has been found in both behavioral and neural studies. In this study, we explored the relationship between rhythmic entrainment, behavioral synchronization, reading fluency, and reading comprehension in neurotypical English- and Mandarin-speaking adults. First, we examined entrainment stability by asking participants to coordinate taps with an auditory metronome in which unpredictable perturbations were introduced to disrupt entrainment. Next, we assessed behavioral synchronization by asking participants to coordinate taps with the syllables they produced while reading sentences as naturally as possible (tap to syllable task). Finally, we measured reading fluency and reading comprehension for native English and native Mandarin speakers. Stability of entrainment correlated strongly with tap to syllable task performance and with reading fluency, and both findings generalized across English and Mandarin speakers.

Cognitive and Linguistic Benefits of Aerobic Exercise: A State-of-the-Art Systematic Review of the Stroke Literature.

This systematic review aimed to determine how aerobic exercise affects cognition after stroke, with particular focus on aphasia and language improvement. Methodological quality was assessed with the PEDro+ scale with half of the 27 included studies rated as high quality. Data extraction focused on cognitive effects of aerobic exercise post-stroke, intervention characteristics, outcome measures, and participant characteristics. Whereas attention, memory, and executive functioning measures were common across the included studies, no study included a language-specific, performance-based measure. Seventeen studies reported positive cognitive effects, most frequently in the domains of attention, memory and executive functioning. Variability in outcome measures, intervention characteristics, and participant characteristics made it difficult to identify similarities among studies reporting positive cognitive effects of exercise or among those studies reporting null outcomes. Only three studies provided specific information about the number of individuals with aphasia included or excluded, who comprise approximately one-third of the stroke population. The review identified patent gaps in our understanding of how aerobic exercise may affect not only the cognitive domain of language post-stroke but also the broader cognitive functioning of individuals with post-stroke aphasia. Methodological limitations of the reviewed studies also warrant further examination of the direct impact of aerobic exercise on cognition post-stroke with careful attention to the selection and reporting of population, intervention, and outcomes.

Primed to cue.

The behavioral effects of lexical priming are well studied in the cognitive sciences. Clinical use of the term and widespread implementation of priming based behavioral interventions has remained limited. This is despite the fact that response-contingent cueing, a behavioral intervention technique used during many cognitive-linguistic interventions, is grounded in theories of priming research. The aim of this manuscript is to connect behavioral performance changes observed following priming with those noted following cueing, providing a theoretical rationale for the therapeutic use of both priming and cueing in language and cognitive interventions. In this review, we establish a conceptual basis for how both primes and cues serve to pre-engage the neural system by triggering the retrieval of linked conceptual knowledge, resulting in faster and more accurate responses. Differences between the two (primes and cues) have been linked to timing and conscious intentional engagement, though these distinctions are often task dependent. Additionally, this paper will provide evidence of the clinical utility of priming. Studies of priming in adults with acquired brain injuries are discussed and clinical interventions based on theories of priming are examined. Furthermore, the present work will briefly detail the inhibitory effects of priming to aid clinicians and researchers in deciding how to pair primes and cues with intended retrieval targets. In summation, the present work is intended to bridge two related fields providing both theoretical and clinical insight with respect to the use of primes and cues.

How are SLPs managing services for people with mild aphasia?

At present, there is limited information on the nature and extent of speech-language pathology services in the U.S. specific to people with mild aphasia (PWMA). The goal of the present study was to determine how speech-language pathologists (SLPs) perceive the assessment, treatment, and discharge of PWMA. According to anecdotal reports from SLPs and PWMA, current services may be inadequate and those with more severe aphasia types are being prioritized. To investigate factors potentially limiting SLP involvement and to determine gaps in service, a 26-question survey, consisting of both open-ended and closed-ended questions, was developed and distributed via email and social media to selected groups of SLPs. A total of 133 SLPs responded to the survey. In this brief report, we discuss only the primary findings. Reports of assessment, treatment, and discharge procedures were diverse; however, a number of central themes were observed. The majority of respondents had more than ten years of experience. They reported greater use of informal measures in assessing people with mild aphasia as compared to people with more severe forms of aphasia. Discharge procedures and recommendations were found to involve primarily referrals to the next level of care, recommendations for continued social interaction, and maintenance programs to preserve treatment progress. Responses tended to be appropriate, yet, not necessarily indicative of the actual standard of care. SLPs reported the need for additional assessment tools and resources in order to better serve people with mild aphasia. Perceived constraints included large caseloads, resource limitations, awareness of health professionals, and the prioritization of those with more severe deficits. Information gathered in this survey highlights the gap in services for this population and provides some tangible guidelines for how to proceed. Given that PWMA have the greatest chance of returning to work, we argue that any prioritization bias should lean toward favoring this population.

Follow-Up on the Story Goodness Index for Characterizing Discourse Deficits Following Traumatic Brain Injury.

Purpose The Story Goodness Index (SGI) is a hybrid analysis of narrative discourse combining 2 macrostructural measures: story grammar and story completeness. Initially proposed by Lê and colleagues ( Lê, Coelho, Mozeiko, & Grafman, 2011 ), the SGI is intended to characterize the discourse performance of individuals with cognitive-communication disorders. In this study, the SGI was utilized to examine the discourse of 2 groups, one with closed head injuries and another with non-brain injured (NBI) peers. The intent of this study was to ascertain whether the SGI could differentiate the discourse performance of the 2 groups, as was previously reported for individuals with penetrating traumatic brain injury and an NBI comparison group ( Lê, Coelho, Mozeiko, Krueger, & Grafman, 2012 ). Because of the retrospective nature of this study, the wordless visual narrative used to elicit discourse was different from the narrative used by Lê and colleagues (2012) . Method A retrospective analysis of discourse was performed on 55 individuals with a history of closed head injury and 47 NBI socioeconomically matched peers. During the initial assessment, participants were engaged in a narrative retell task. Each participant was shown a wordless picture story and then asked to retell the story to the examiner. Story narratives were reanalyzed for story grammar (organization) and completeness (critical content). Results A significant group difference was noted for the story grammar measure, but not for story completeness. Although the SGI plots depicted the heterogeneity in discourse performance of the 2 groups, a chi-square test of independence revealed no significant association between group membership and SGI quadrant. Conclusions Findings from this study were inconsistent with those of Lê and colleagues. The studies did not use identical SGI protocols; specifically, different picture stimuli were used to elicit the story retells. Therefore, this study cannot be considered a replication. The story used by Lê and colleagues was judged to be more complex, requiring more inference for story interpretation. Future studies should interpret findings within the context of the story stimuli presented.

Changes in discourse structure over time following traumatic brain injury.

The objective of the present study was to investigate structural changes in the narrative discourse of individuals with penetrating traumatic brain injury (pTBI) following immediate and delayed story retellings. Additionally, the potential influence of immediate memory, working memory, and executive functions on narrative discourse performance were examined. The narrative discourse of two groups, 123 with pTBI and 44 non-brain injured (NBI), was sampled. Participants were asked to retell a wordless picture story immediately after viewing it and again 30-min later. Story narratives were analyzed using a variety of microlinguistic and macrostructural measures. Results revealed significant group differences of both microlinguistic and macrostructural measures following the immediate retell, but not following the delayed retell. Regression analyses revealed that immediate memory accounted for a modest degree of the explained variance for the production of critical content during narrative discourse. The observed deficits were relatively stable over a short delay (30 min) and appeared attributable, in part, to difficulty with the encoding and consolidation of story content.

Treatment Response to a Double Administration of Constraint-Induced Language Therapy in Chronic Aphasia.

Purpose: This study investigated changes in oral-verbal expressive language associated with improvements following 2 treatment periods of constraint-induced language therapy in 4 participants with stroke-induced chronic aphasia. Generalization of treatment to untrained materials and to discourse production was also analyzed, as was the durability of the treatment effect. Method: Participants with aphasia were assessed using standardized measures and discourse tasks at 3 to 4 time points to document behavioral changes throughout each of two 30-hr treatment periods of constraint-induced language therapy. Daily probes of trained and untrained materials were also administered. Results: Despite participant heterogeneity, behavioral results for each person with aphasia indicated a positive response to treatment following each treatment period indicated by performance on standardized tests, trained materials, or both. Treatment effects generalized to some degree to untrained stimuli and to discourse measures and were generally maintained at follow-up testing. Conclusions: Data support the utility of a 2nd treatment period. Results are relevant to rehabilitation in chronic aphasia, confirming that significant language gains continue well past the point of spontaneous recovery and can occur in a relatively short time period. Importantly, changes are not confined to a single treatment period, suggesting that people with aphasia may benefit from multiple doses of high-intensity treatment.

Does brain volume loss predict cognitive and narrative discourse performance following traumatic brain injury?

PURPOSE: In this study, the authors investigated the relationship between brain volume loss and performance on cognitive measures, including working memory, immediate memory, executive functions, and intelligence, and a narrative discourse production task. An underlying goal was to examine the prognostic potential of a brain lesion metric for discourse outcomes. It was hypothesized that brain volume loss would correlate with and predict cognitive and narrative discourse measures and have prognostic value for discourse outcomes. METHOD: One hundred sixty-seven individuals with penetrating head injury participated. Correlational and regression analyses were performed for the percentages of total brain and hemispheric volume loss and scores on 4 cognitive measures (WMS-III Working Memory and Immediate Memory primary indexes, D-KEFS Sorting Test, and WAIS-III Full Scale IQ) and 7 narrative discourse measures (T-units, grammatical complexity, cohesion, local and global coherence, story completeness, and story grammar). RESULTS: The volumetric measures had significant small-to-moderate correlations with all cognitive measures but only one significant correlation with the discourse measures. Findings from regression analyses were analogous but revealed several models that approached significance. CONCLUSION: Findings suggest that an overall measure of brain damage may be more predictive of general cognitive status than of narrative discourse ability. Atrophy measures in specific brain regions may be more informative.

Characterizing discourse deficits following penetrating head injury: a preliminary model.

PURPOSE: Discourse analyses have demonstrated utility for delineating subtle communication deficits following closed head injuries (CHIs). The present investigation examined the discourse performance of a large group of individuals with penetrating head injury (PHI). Performance was also compared across 6 subgroups of PHI based on lesion locale. A preliminary model of discourse production following PHI was proposed and tested. METHOD: Story narratives were elicited from 2 groups of participants, 167 with PHI and 46 non brain-injured (NBI). Micro- and macrostructural components of each story were analyzed. Measures of memory, executive functions, and intelligence were also administered. All measures were compared across groups and PHI subgroups. The proposed model of discourse production was tested with a structural equation modeling procedure. RESULTS: No differences for the discourse measures were noted across the six PHI subgroups. Three measures distinguished the PHI and NBI groups: narrative length, story grammar, and completeness. The proposed model of discourse production had an adequate-to-good fit with the cognitive and discourse data. CONCLUSION: In spite of differing mechanisms of injury, the PHI group's discourse performance was consistent with what has been reported for individuals with CHI. The model tested represents a preliminary step toward understanding discourse production following traumatic brain injury.

Discourse production following injury to the dorsolateral prefrontal cortex.

Individuals with damage to the prefrontal cortex, and the dorsolateral prefrontal cortex (DLPFC) in particular, often demonstrate difficulties with the formulation of complex language not attributable to aphasia. The present study employed a discourse analysis procedure to characterize the language of individuals with left (L) or right (R) DLPFC lesions. All participants were 30-35 years post-onset of injury and presented with persistent discourse impairments. The discourse performance of the R DLPFC group was not significantly different from either the L DLPFC group or the non-injured comparison group. Individuals from the L DLPFC group demonstrated specific difficulties with narrative coherence and inclusion of critical story components. Both measures were significantly different from the comparison group. The discourse ability of the DLPFC groups was significantly correlated with measures of working memory. Findings support the use of discourse analysis for examining language impairments in individuals with PFC lesions.

Predicting story goodness performance from cognitive measures following traumatic brain injury.

PURPOSE: This study examined the prediction of performance on measures of the Story Goodness Index (SGI; Lê, Coelho, Mozeiko, & Grafman, 2011) from executive function (EF) and memory measures following traumatic brain injury (TBI). It was hypothesized that EF and memory measures would significantly predict SGI outcomes. METHOD: One hundred sixty-seven individuals with TBI participated in the study. Story retellings were analyzed using the SGI protocol. Three cognitive measures--Delis-Kaplan Executive Function System (D-KEFS; Delis, Kaplan, & Kramer, 2001) Sorting Test, Wechsler Memory Scale--Third Edition (WMS-III; Wechsler, 1997) Working Memory Primary Index (WMI), and WMS-III Immediate Memory Primary Index (IMI)--were entered into a multiple linear regression model for each discourse measure. Two sets of regression analyses were performed, the first with the Sorting Test as the first predictor and the second with it as the last. RESULTS: The first set of regression analyses identified the Sorting Test and IMI as the only significant predictors of performance on measures of the SGI. The second set identified all measures as significant predictors when evaluating each step of the regression function. CONCLUSION: The cognitive variables predicted performance on the SGI measures, although there were differences in the amount of explained variance. The results (a) suggest that storytelling ability draws on a number of underlying skills and (b) underscore the importance of using discrete cognitive tasks rather than broad cognitive indices to investigate the cognitive substrates of discourse.

Measuring goodness of story narratives.

PURPOSE: The purpose of this article was to evaluate a new measure of story narrative performance: story completeness. It was hypothesized that by combining organizational (story grammar) and completeness measures, story "goodness" could be quantified. METHOD: Discourse samples from 46 typically developing adults were compared with those from 24 adults with acquired brain injuries. Story retellings were elicited and analyzed for episode structure (story grammar). Each story was also evaluated for the presence of 5 key components, yielding the story completeness score. Story goodness was quantified by combining the story grammar and completeness measures using a 2-coordinate grid system. A multivariate analysis of variance was performed as well as correlational analyses between the story grammar and story completeness scores. RESULTS: There were significant group differences on both story grammar and story completeness. Moderate correlations were noted between the 2 measures, suggesting that the indices were not entirely measuring the same abilities. Plotting the 2 sets of scores into quadrants discriminated the comparison group and the group with brain injury into 4 distinct categories of story "goodness." CONCLUSION: The combination of measures provided a more accurate depiction of discourse performance than either measure alone. Results suggest the measure is sensitive, is reliable, and has potential utility for investigating discourse deficits in clinical populations.