Reviewing the quality of discourse information measures in aphasia

A feasibility randomised waitlist-controlled trial of a personalised multi-level language treatment for people with aphasia: The remote LUNA study

BACKGROUND

Stroke survivors with aphasia want to improve their everyday talking (discourse). In current UK practice, 90% of speech and language therapists believe discourse assessment and treatment is part of their role but are hampered by barriers in resources, time and expertise. There is a clinical need for well-articulated discourse assessment and treatments. LUNA is a multi-level treatment targeting words, sentences and discourse macrostructure in personal stories that addresses this clinical need.

OBJECTIVES

This study aimed to assess the feasibility and acceptability of LUNA trial procedures in a randomised waitlist-controlled trial; and to evaluate preliminary efficacy.

METHODS

This paper reports a phase II, waitlist-controlled, proof-of-concept feasibility trial. Participants with chronic aphasia (n = 28) were recruited from the community and randomised to an Immediate (n = 14) or Delayed (n = 14) group. LUNA treatment was delivered twice weekly for 10 weeks via the videoconferencing technology, Zoom. Feasibility was assessed in terms of participant recruitment and retention, adherence, missing data, and treatment fidelity. Preliminary treatment efficacy was assessed in terms of between group differences in outcome measures relating to discourse, language, and psychosocial state.

RESULTS

The remote LUNA trial was feasible: 85% of those eligible consented to the trial; trial retention was 86%; 87% of treatment sessions were delivered as scheduled, and 79% of participants completed 80%+ of the treatment programme; data was missing only for participants who withdrew; treatment fidelity was high at 92% adherence; and only one clinical outcome measure demonstrated ceiling effects. ANCOVA analysis of the clinical outcome measures revealed group differences with medium and large effect sizes, indicating, improvements in the production of words, sentences, discourse macrostructure, overall language functioning (WAB-R), and psychosocial state (VAMS) following LUNA treatment. For most outcomes measured, similar treatment benefits were suggested in a secondary, non-parametric analysis.

CONCLUSIONS

Large-scale evaluation of the clinical efficacy and cost-effectiveness of LUNA is warranted and supported by these findings.

TRIAL REGISTRATION

Clinical trials registration: NCT05847023 (clinical trials.gov).

Verb Tense Production in People With Nonfluent Aphasia Across Different Discourse Elicitation Tasks

PURPOSE

Verb tense production is known to be impaired in people with nonfluent aphasia. Selective past tense impairment in this population has been reported, but results are inconsistent and lacking at the discourse level. In addition, language production can be affected by discourse elicitation tasks depending on the cognitive linguistic demands and instructions unique to each task. There is limited evidence regarding whether verb tense production in people with nonfluent aphasia is impacted by discourse task demands. Understanding this potential impact is important for clinicians and researchers who are interested in assessing and then identifying effective clinical goals for this population. Therefore, this study aimed to investigate the trends of verb tense production across various discourse elicitation tasks in people with nonfluent aphasia compared to people without aphasia.

METHOD

Language samples for 23 people with nonfluent aphasia and 27 people without aphasia were obtained for six discourse tasks from the AphasiaBank database. We calculated ratios of past tense, present tense, future tense, imperative, and unknown verb types to compare which tense was used most frequently within and across the tasks and groups.

RESULTS AND CONCLUSIONS

Our findings revealed evidence of verb tense production deficits and a selective past tense impairment in people with nonfluent aphasia. Discourse task effects were shown for people without aphasia but were scarce in people with nonfluent aphasia. This finding could be explained by an overall reduction of verb production and overreliance on present tense production in nonfluent aphasia. These results suggest the potential methodological implications of using different discourse tasks to evaluate verb tense production in people with nonfluent aphasia. Future studies need to evaluate discourse task effects on other aspects of verb production (e.g., moods) and specific task factors (e.g., presence or absence of visual stimulus).

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25146242.

Towards efficient, ecological assessment of interaction: A scoping review of co-constructed communication

BACKGROUND

The complexity of communication presents challenges for clinical assessment, outcome measurement and intervention for people with acquired brain injury. For the purposes of assessment or treatment, this complexity is usually managed by isolating specific linguistic functions or speech acts from the interactional context. Separating linguistic functions from their interactional context can lead to discourse being viewed as a static entity comprised of discrete features, rather than as a dynamic process of co-constructing meaning. The ecological validity of discourse assessments which rely on the deconstruction of linguistic functions is unclear. Previous studies have reported assessment tasks that preserve some of the dialogic features of communication, but as yet, these tasks have not been identified as a distinct genre of assessment. We suggest the term 'co-constructed communication' to describe tasks which are specifically designed to capture the dynamic, jointly produced nature of communication within a replicable assessment task.

AIMS

To identify and summarize how co-constructed communication has been assessed with individuals with non-progressive acquired communication disability regarding task design, measures and psychometric robustness.

METHODS

A scoping review methodology was used to identity relevant studies. Systematic database searches were conducted on studies published before July 2021. Studies in the yield were assessed against eligibility criteria, with 37 studies identified as eligible for inclusion.

MAIN CONTRIBUTION

This is the first time that co-constructed communication has been defined as a genre of discourse assessment for stroke and traumatic brain injury populations. Co-constructed communication has been assessed for 144 individuals with aphasia and 111 with cognitive-communication disability. Five categories of co-constructed communication tasks were identified, ranging in complexity. Variability exists in how these assessment tasks are labelled and measured. Assessment measures require further psychometric profiling, specifically regarding test-retest reliability and validity.

CONCLUSIONS

Co-constructed communication is a discourse genre which offers researchers and clinicians a replicable method to assess language and communication in an experimentally rigorous way, within an ecologically valid context, bridging the gap between experimental and ecological assessment approaches.

WHAT THIS PAPER ADDS

What is already known on this subject Standardized assessments of language skills and monologue offer reliable, replicable ways to measure language. However, isolating language from an interactional context fundamentally changes the behaviour under study. This raises questions about the ecological validity of the measures we routinely use to determine diagnoses, guide treatment planning and measure the success of treatment. What this study adds to the existing knowledge This review highlights studies that conceptualize, and often quantify, interaction by combining experimental rigour and aspects of everyday dialogue. This is the first time this genre of discourse assessment has been identified. We propose the term 'co-constructed communication' to describe this genre and provide an operational definition for the term. What are the practical and clinical implications of this study? Co-constructed communication assessment tasks require refinement, particularly regarding aspects of psychometric robustness. In the future, these tasks offer pragmatic, meaningful ways to capture the effect and impact of aphasia and cognitive-communication disability within interaction.

Reliability of the picture description task of the Western Aphasia Battery - revised in Laurentian French persons without brain injury

Objective: Limited normative data (including psychometric properties) are currently available on discourse tasks in non-dominant languages such as Laurentian (Quebec) French. The lack of linguistic and cultural adaptation has been identified as a barrier to discourse assessment. The main aim of this study is to document inter-rater and test-retest reliability properties of the picnic scene of the Western Aphasia Battery - Revised (WAB-R), including the cultural adaptation of an information content unit (ICU) list, and provide a normative reference for persons without brain injury (PWBI). Method: To do so, we also aimed to adapt an ICU checklist culturally and linguistically for Laurentian French speakers. Discourse samples were collected from 66 PWBI using the picture description task of the WAB-R. The ICU list was first adapted into Laurentian French. Then, ICUs and thematic units (TUs) were extracted manually, and microstructural variables were extracted using CLAN. Inter-rater reliability and test-retest reliability were determined. Results: Excellent inter-rater reliability was obtained for ICUs and TUs, as well as for all microstructural variables, except for mean length of utterance, which was found to be good. Conversely, test-retest reliability ranged from poor to moderate for all variables. Conclusion: The present study provides a validated ICU checklist for clinicians and researchers working with Laurentian French speakers when assessing discourse with the picnic scene of the WAB-R. It also addresses the gap in available psychometric data regarding inter-rater and test-retest reliability in PWBI.

Discourse Task Type-Specific Linguistic Characteristics in Anomic Aphasia and Healthy Controls: Evidence From Mandarin-Chinese AphasiaBank

PURPOSE

This study was designed to examine the hypothesis that discourse task types influence language performance in Mandarin Chinese-speaking people and to reveal the discourse task-specific linguistic properties of persons with anomic aphasia compared to neurotypical controls.

METHOD

Language samples from persons with aphasia (n = 31) and age- and education-matched controls (n = 31) across four discourse tasks (sequential-picture description, single-picture description, story narrative, and procedural discourse) were collected from Mandarin AphasiaBank. Task-specific distributions of parts of speech were analyzed using mosaic plots. The main effects of tasks in each group and the between-group differences within each task for several typical linguistic variables were evaluated, including the mean length of utterance, tokens, moving-average type-token ratio, words per minute, propositional density, noun-verb ratio, noun percentage, and verb percentage.

RESULTS

The results revealed an impact of discourse tasks on most language variables in both groups. In the healthy controls, story narratives yielded the highest total words and lowest verb percentage. In the aphasia group, procedural discourse elicited the fewest total words and densest expressions, whereas their single-picture descriptions had the highest noun-verb ratio. For all tasks, the aphasia group performed worse than the control group in the mean length of utterance, tokens, moving-average type-token ratio, and words per minute. For noun-verb ratio, noun percentage, and verb percentage, only one task (i.e., single-picture description) showed significant between-group differences.

CONCLUSION

The selection of discourse tasks should be addressed in assessments and interventions for Mandarin Chinese-speaking individuals with aphasia to obtain more accurate and feasible outcomes.

Story Grammar Analyses Capture Discourse Improvement in the First 2 Years Following a Severe Traumatic Brain Injury

PURPOSE

Narration within a story grammar framework requires speakers to organize characters and events logically. Despite abundant research characterizing narrative deficits following a traumatic brain injury (TBI), the evolution of narrative story grammar over the first 2 years post-TBI has rarely been explored. This study analyzed story grammar in complex narratives of adults with and without severe TBI to (a) examine between-group differences and (b) investigate longitudinal changes over the first 2 years post-TBI.

METHOD

Story grammar analyses of Cinderella narratives from 57 participants with TBI and 57 participants with no brain injury yielded measures of productivity (total number of episodes, total number of story grammar elements), elaboration (total number of elaborated-complete episodes, mean number of episodic elements per episode), and completeness (total number of incomplete episodes). Mann-Whitney U tests compared measures across groups; generalized estimating equation (GEE) models identified predictors of change, including recovery time (3, 6, 9, 12, and 24 months post-TBI) and demographic/injury-related characteristics.

RESULTS

Between-group differences were statistically significant for all productivity and elaboration measures at 3, 6, and 9 months post-TBI; one productivity measure and one elaboration measure at 12 months; and none of the measures at 24 months. GEE models showed significant improvements in all productivity and elaboration measures over the first 24 months post-TBI, with educational attainment and duration of posttraumatic amnesia affecting recovery. Incomplete episodes only showed between-group differences at 12 months and did not capture recovery.

CONCLUSION

Productivity and elaboration are key story grammar variables that (a) differentiate complex narration in individuals with and without severe TBI and (b) capture narrative improvements over the first 2 years post-TBI.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25148999.

Correct Information Unit Analysis in Different Discourse Tasks Among Persons With Anomic Aphasia Based on Mandarin AphasiaBank

PURPOSE

This study aimed to explore how well persons with anomic aphasia communicate information during discourse regarding quantity, quality, and efficiency compared to neurotypical controls, to investigate the influence of discourse tasks on informativeness and efficiency and to examine impact factors like aphasia severity and cognitive ability.

METHOD

Language samples of four discourse tasks from 31 persons with anomic aphasia and 31 neurotypical controls were collected from Mandarin AphasiaBank. Correct information unit (CIU) analysis measures including the total number of CIUs, percentage of CIUs, CIUs per minute, and words per minute were calculated. Group differences and the effects of discourse tasks on informativeness and efficiency were investigated. Correlations of CIU analysis measures with aphasia severity and cognitive ability were examined.

RESULTS

Persons with anomic aphasia showed lower efficiency in conveying information than controls. They underperformed controls on all CIU analysis measures when executing story narrative tasks. Discourse tasks influenced the informativeness and efficiency of both groups. Neurotypical controls delivered the greatest quantity of information most efficiently when narrating stories. Persons with anomic aphasia exhibited reduced quantity of information during procedural discourse and displayed superior information quality in sequential-picture descriptions. Discourse information may be impacted by aphasia severity and cognitive ability, with varying effects depending on the task.

CONCLUSIONS

Persons with anomic aphasia are inefficient in communicating discourse messages and perform poorly on all measures in story narratives. When measuring discourse information, the effects of discourse tasks and factors like aphasia severity and cognitive ability should be considered.

Written discourse in diagnosis for acquired neurogenic communication disorders: current evidence and future directions

Purpose

We aimed to perform the first review of research focusing on written discourse performance in people with acquired neurogenic communication disorders. In studies from 2000 onward, we specifically sought to determine: (1) the differences between patient populations and control groups, (2) the differences between different patient populations, (3) longitudinal differences between patient populations, and (4) modality differences between spoken and written discourse performance.

Methods

We completed a thorough search on MEDLINE, Embase, Cochrane, APAPsycinfo, Web of Science, and Scopus databases. We identified studies that focus on written discourse performance in people with aphasia, primary progressive aphasia, mild cognitive impairment, and Alzheimer's disease.

Results

Nineteen studies were identified from the review of literature, some of which addressed more than one of our review questions. Fifteen studies included a comparison between clinical populations and controls. Six studies compared different characteristics of patient populations. Three studies reported changes over time in progressive disorders. Six studies targeted different modalities of discourse.

Conclusion

Differences in linguistic features by patient populations are not yet clear due to the limited number of studies and different measures and tasks used across the studies. Nevertheless, there is substantial evidence of numerous linguistic features in acquired neurogenic communication disorders that depart from those of healthy controls. Compared to the controls, people with aphasia tend to produce fewer words, and syntactically simpler utterances compared to the controls. People with Alzheimer's disease produce less information content, and this feature increases over time, as reported in longitudinal studies. Our review imparts additional information that written and spoken discourse provide unique insights into the cognitive and linguistic deficits experienced by people with aphasia, Alzheimer's disease, mild cognitive impairment and primary progressive aphasia and provide targets for treatment to improve written communication in these groups.

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.

Can Narrative Skills Improve in Autism Spectrum Disorder? A Preliminary Study with Verbally Fluent Adolescents Receiving the Cognitive Pragmatic Treatment

Autism spectrum disorder (ASD) is a neurodevelopmental condition affecting social and communicative skills, including narrative ability, namely the description of real-life or fictive accounts of temporally and causally related events. With this study, we aimed to determine whether a communicative-pragmatic training, i.e., the version for adolescents of the Cognitive-Pragmatic Treatment, is effective in improving the narrative skills of 16 verbally fluent adolescents with ASD. We used a multilevel approach to assess pre- and post-training narrative production skills. Discourse analysis focused on micro- (i.e., mean length of utterance, complete sentences, omissions of morphosyntactic information) and macrolinguistic measures (i.e., cohesion, coherence errors, lexical informativeness). Results revealed a significant improvement in mean length of utterance and complete sentences and a decrease in cohesion errors. No significant change was found in the other narrative measures investigated. Our findings suggest that a pragmatically oriented training may be useful in improving grammatical efficiency in narrative production.

Measuring communication as a core outcome in aphasia trials: Results of the ROMA-2 international core outcome set development meeting

BACKGROUND

Evidence-based recommendations for a core outcome set (COS; minimum set of outcomes) for aphasia treatment research have been developed (the Research Outcome Measurement in Aphasia-ROMA, COS). Five recommended core outcome constructs: communication, language, quality of life, emotional well-being and patient-reported satisfaction/impact of treatment, were identified through three international consensus studies. Constructs were paired with outcome measurement instruments (OMIs) during an international consensus meeting (ROMA-1). Before the current study (ROMA-2), agreement had not been reached on OMIs for the constructs of communication or patient-reported satisfaction/impact of treatment.

AIM

To establish consensus on a communication OMI for inclusion in the ROMA COS.

METHODS & PROCEDURES

Research methods were based on recommendations from the Core Outcome Measures in Effectiveness Trials (COMET) Initiative. Participants with expertise in design and conduct of aphasia trials, measurement instrument development/testing and/or communication outcome measurement were recruited through an open call. Before the consensus meeting, participants agreed on a definition of communication, identified appropriate OMIs, extracted their measurement properties and established criteria for their quality assessment. During the consensus meeting they short-listed OMIs and participants without conflicts of interest voted on the two most highly ranked instruments. Consensus was defined a priori as agreement by ≥ 70% of participants.

OUTCOMES & RESULTS

In total, 40 researchers from nine countries participated in ROMA-2 (including four facilitators and three-panel members who participated in pre-meeting activities only). A total of 20 OMIs were identified and evaluated. Eight short-listed communication measures were further evaluated for their measurement properties and ranked. Participants in the consensus meeting (n = 33) who did not have conflicts of interest (n = 29) voted on the top two ranked OMIs: The Scenario Test (TST) and the Communication Activities of Daily Living-3 (CADL-3). TST received 72% (n = 21) of 'yes' votes and the CADL-3 received 28% (n = 8) of 'yes' votes.

CONCLUSIONS & IMPLICATIONS

Consensus was achieved that TST was the preferred communication OMI for inclusion in the ROMA COS. It is currently available in the original Dutch version and has been adapted into English, German and Greek. Further consideration must be given to the best way to measure communication in people with mild aphasia. Development of a patient-reported measure for satisfaction with/impact of treatment and multilingual versions of all OMIs of the COS is still required. Implementation of the ROMA COS would improve research outcome measurement and the quality, relevance, transparency, replicability and efficiency of aphasia treatment research.

WHAT THIS PAPER ADDS

What is already known on this subject International consensus has been reached on five core constructs to be routinely measured in aphasia treatment studies. International consensus has also been established for OMIs for the three constructs of language, quality of life and emotional well-being. Before this study, OMIs for the constructs of communication and patient-reported satisfaction/impact of treatment were not established. What this paper adds to existing knowledge We gained international consensus on an OMI for the construct of communication. TST is recommended for inclusion in the ROMA COS for routine use in aphasia treatment research. What are the potential or actual clinical implications of this work? The ROMA COS recommends OMIs for a minimum set of outcomes for adults with post-stroke aphasia within phases I-IV aphasia treatment research. Although not intended for clinical use, clinicians may employ the instruments of the ROMA COS, considering the quality of their measurement properties. The systematic inclusion of a measure of communication, such as TST, in clinical practice could ultimately support the implementation of research evidence and best practices.

Test-Retest Reliability of Microlinguistic Information Derived From Spoken Discourse in Persons With Chronic Aphasia

PURPOSE

The purpose of this study was to characterize test-retest reliability of discourse measures across a battery of common tasks in individuals with aphasia and prospectively matched adults without brain damage.

METHOD

We collected spoken discourse during five monologue tasks at two timepoints (test and retest; within 2 weeks apart) in an aphasia group (n = 23) and a peer group with no brain damage (n = 24). We evaluated test-retest reliability for percentage of correct information units, correct information units per minute, mean length of utterance, verbs per utterance, noun/verb ratio, open/closed class word ratio, tokens, sample duration (seconds), propositional idea density, type-token ratio, and words per minute. We explored reliability's relationship with sample length and aphasia severity.

RESULTS

Rater reliability was excellent. Across tasks, both groups demonstrated discourse measures with poor, moderate, and good reliability, with the aphasia group having measures demonstrating excellent test-retest reliability. When evaluating measures within each task, test-retest reliability again ranged from poor to excellent for both groups. Across groups and task, measures that appeared most reliable appeared to reflect lexical, informativeness, or fluency information. Sample length and aphasia severity impacted reliability, and this differed across and by task.

CONCLUSIONS

We identified several discourse measures that were reliable across and within tasks. Test-retest statistics are intimately linked to the specific sample, emphasizing the importance of multiple baseline studies. Task itself should be considered an important variable, and it should not be assumed that discourse measures found to be reliable across several tasks (averaged) are likewise reliable for a single task.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23298032.

Descriptive discourse in fluent aphasia: The predictive role of attention, phonology, lexical retrieval and semantics

AIMS

To study the relationship between cognitive and linguistic skills (as measured through standardized tasks) over spontaneous speech elicited during a picture description task.

METHODS & PROCEDURES

21 controls and 19 people with fluent aphasia matched by age and sex were evaluated using transcripts made from a picture description task coded using the CHAT format and analyzed using Computerized Language Analysis (CLAN). Indices obtained from the speech samples contained measures of lexical quantity and diversity, morphosyntactic complexity, informativeness, and speech fluency, along with different kinds of speech errors. We studied their correlations with attentional measures from Conners' Continuous Performance Test and with standardized measures of naming, pseudoword repetition and semantic non-verbal association. We further used stepwise linear regression to analyze the predictive value of standardized linguistic and cognitive skills over discursive indices.

OUTCOMES & RESULTS

Contrary to our initial hypothesis, there were no significant correlations between attentional scores and discourse variables in aphasic participants. Moreover, semantic association, along with naming, was the measure more related with discourse performance in people with fluent aphasia, but cognitive and linguistic standardized measures had overall little predictive power on most discourse indices. In the control group, there was a certain association of naming skills and attentional reaction time with discourse variables, but their predictive power was also low.

CONCLUSIONS & IMPLICATIONS

The current results do not support a strong relationship between basic attentional skills and performance in descriptive discourse in fluent aphasia. Although some of the standardized tasks seem to bear some relationship with spontaneous speech, there is a high amount of interindividual variability in discourse that is not captured by classical cognitive tasks routinely used in assessment. Further work on the determinants of discourse performance in aphasia and on the clinical application of discourse analysis is warranted.

Conversation as an Outcome of Aphasia Treatment: A Systematic Scoping Review

PURPOSE

Conversation-focused speech-language pathology services are a top priority for people living with aphasia, but little is known about how researchers measure conversation as an outcome of treatment. This scoping review was undertaken to systematically review the evidence regarding the measurement of conversation in aphasia studies and to identify current practices and existing gaps.

METHOD

A systematic literature search was conducted for studies published between January 1995 and September 2019 in multiple electronic databases. Covidence software was used to manage search results, study selection, and data charting processes. Data were extracted from each study and then collated and organized to elucidate the breadth of approaches, tools, or procedures oriented to measuring conversation as an outcome and identify gaps in the existing literature.

RESULTS

The systematic search of the literature resulted in 1,244 studies. A total of 64 studies met inclusion criteria and were included in the review. The review summarizes the various tools and procedures used to measure conversation as an outcome of aphasia intervention, including variations in data collection and analysis procedures. The review also evaluates the quality of conversation measures in terms of psychometric properties and informal measures of validity. There was a total of 211 measures used across the 64 studies.

CONCLUSIONS

While there was no clear measure that was objectively superior, several measures show promise and warrant future exploration. Some of the orientations, conceptualizations, and procedures we have presented can be seen as options that might be included in a future conversation-focused core outcome set.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21514062.

Two-Year Longitudinal Evaluation of Community Aphasia Center Participation on Linguistic, Functional Communication, and Quality of Life Measures Across People With a Range of Aphasia Presentations

PURPOSE

The purpose of this study was to evaluate potential changes on a hierarchy of language tasks and measures of functional communication and quality of life in a group of people with aphasia (PWA) who attended a community aphasia center for 2 years. A secondary purpose was to determine whether there were any predictors of change.

METHOD

Twenty-seven PWA who attended Brooks Rehabilitation Aphasia Center (BRAC) were evaluated on an aphasia battery, confrontation naming, and structured discourse in addition to completing self-reported measures of functional communication and quality of life at three time points: before attending BRAC and after 1 (N = 27) and 2 (N = 20) years of BRAC participation. Twenty-six communication partners who communicated regularly with the PWA completed a questionnaire about their functional communication at the same time points. A mixed linear model was conducted for all dependent variables to determine change over time. Tau-b correlations were conducted between demographic and aphasia-related variables and difference scores for outcome measures that exhibited significant improvements.

RESULTS

At 1-year testing, significant improvements were observed on the aphasia battery, object and action naming, and all self- and communication partner-reported measures. At 2-year testing, all improvements were maintained except for the self-reported measure of functional communication. Structured discourse showed increases in average number of words, percentage of meaningful words and utterances, and efficiency of meaningful word production after 2 years. No significant correlations were observed between predictor variables and difference scores.

CONCLUSIONS

Participation in aphasia centers can result in significant changes in language, functional communication, and quality of life in people with chronic aphasia. These findings support the importance of aphasia centers in the continuum of care for PWA.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21313689.

Quality of Measurement in Core Lexicon Measures

PURPOSE

Core lexicon measures have received growing attention in research. They are intended to provide clinicians with a clinician-friendly means to quantify word retrieval ability in discourse based on normal expectations of discourse production for specific discourse elicitation tasks. To date, different criteria have been used to develop core lexicon measures by groups of researchers. The need for statistical guidance in pursuit of the psychologically robust measure has been recognized.

AIMS

This study was to investigate the best criterion for accurate measurement. Specifically, we focused on two criteria (frequency vs. percentage) that have previously been used for the development of core lexicon measures.

METHOD

Core lexicon measures consisting of five different checklists by word class (verbs, nouns, adjectives, adverbs, and function words) and developed by the two criteria were applied to language samples produced by 470 cognitively healthy adults. Performance in word retrieval ability at the discourse level was modeled as a latent variable based on the observed proportions of the production of core lexicon items in two different sets of core lexicon measures using structural equation modeling.

RESULTS

Results indicated that both criterion for core lexicon measures capture word retrieval ability in discourse. Greater residual variances were found in the core lexicon measure established by the percentage criterion compared to the one established by the frequency criterion. This indicates that the measure based on the percentage criterion is more affected by measurement errors.

CONCLUSIONS

The findings provide evidence that the frequency criterion is better to use for the development of core lexicon measures for core nouns, verbs, adjectives, and adverbs, but not for function words. However, our findings are limited to core lexicon measures based on language samples elicited by wordless picture books. This may not be easily applied to other core lexicon measures that use different discourse elicitation tasks due to the difference in quality and quantity of language samples. Ideally, the same approach should be replicated to evaluate the appropriateness of respective criteria in the development of core lexicon measures.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20304144.

Validation of an Automated Procedure for Calculating Core Lexicon From Transcripts

PURPOSE

The aim of this study was to advance the use of structured, monologic discourse analysis by validating an automated scoring procedure for core lexicon (CoreLex) using transcripts.

METHOD

Forty-nine transcripts from persons with aphasia and 48 transcripts from persons with no brain injury were retrieved from the AphasiaBank database. Five structured monologic discourse tasks were scored manually by trained scorers and via automation using a newly developed CLAN command based upon previously published lists for CoreLex. Point-to-point (or word-by-word) accuracy and reliability of the two methods were calculated. Scoring discrepancies were examined to identify errors. Time estimates for each method were calculated to determine if automated scoring improved efficiency.

RESULTS

Intraclass correlation coefficients for the tasks ranged from .998 to .978, indicating excellent intermethod reliability. Automated scoring using CLAN represented a significant time savings for an experienced CLAN user and for inexperienced CLAN users following step-by-step instructions.

CONCLUSIONS

Automated scoring of CoreLex is a valid and reliable alternative to the current gold standard of manually scoring CoreLex from transcribed monologic discourse samples. The downstream time saving of this automated analysis may allow for more efficient and broader utilization of this discourse measure in aphasia research. To further encourage the use of this method, go to https://aphasia.talkbank.org/discourse/CoreLexicon/ for materials and the step-by-step instructions utilized in this project.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20399304.

Macrostructural Aspects in Oral Narratives in Brazilian Portuguese by Left and Right Hemisphere Stroke Patients With Low Education and Low Socioeconomic Status

OBJECTIVE

Individuals with a stroke in either the left hemisphere (LH) or the right hemisphere (RH) often present macrostructural impairments in narrative abilities. Understanding the potential influence of low education and low socioeconomic status (SES) is critical to a more effective assessment of poststroke language. The first aim was to investigate macrostructural processing in low-education and low-SES individuals with stroke in the LH or RH or without brain damage. The second aim was to verify the relationships between macrolinguistic, neuropsychological, and sociodemographic variables.

METHOD

Forty-seven adults with LH (n = 15) or RH (n = 16) chronic ischemic stroke and 16 matched (age, education, and SES) healthy controls produced three oral picture-sequence narratives. The macrostructural aspects analyzed were cohesion, coherence, narrativity, macropropositions, and index of lexical informativeness and were compared among the three groups. Then, exploratory correlations were performed to assess associations between sociodemographic (such as SES), neuropsychological, and macrostructural variables.

RESULTS

Both the LH and the RH presented impairments in the local macrostructural aspect (cohesion), whereas the RH also presented impairments in more global aspects (global coherence and macropropositions). All five macrostructural variables correlated with each other, with higher correlations with narrativity. Naming was correlated with all macrostructural variables, as well as prestroke reading and writing habits (RWH), showing that higher naming accuracy and higher RWH are associated with better macrostructural skills.

CONCLUSIONS

The present results corroborate the role of the LH in more local processing and that of the RH in more global aspects of discourse. Moreover, this study highlights the importance of investigating discourse processing in healthy and clinical populations of understudied languages such as Brazilian Portuguese, with various levels of education, SES, and RWH.

Sentence Production in a Discourse Context in Latent Aphasia: A Real-Time Study

PURPOSE

The purpose of this study was to improve our understanding as to which factors determine online, spoken sentence production abilities of adults with latent aphasia in a discourse context.

METHOD

Discourse samples of the story of Cinderella elicited from AphasiaBank were analyzed with speech analysis software. Participants comprised people with latent and anomic aphasia as well as neurotypical controls (10 per group). Durations of pauses (silent and filled) were analyzed according to (a) the location they occurred (between or within sentences), (b) the syntactic complexity of sentences (simple, complex), and (c) sentence length (number of words). Statistical comparisons were conducted using mixed-effect models.

RESULTS

The two clinical groups (latent and anomic) differed from controls in the duration of pauses, both between and within sentences. Syntactic complexity did not exert an effect on either of the two clinical groups as compared with controls. As compared with controls, both clinical groups paused more before long in comparison with short sentences.

CONCLUSION

Reduction in processing speed, which affects the ability to simultaneously maintain multiple linguistic and other cognitive demands associated with planning and monitoring of utterances, is a major factor that compromises sentence production in spoken discourse in latent aphasia.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19448726.

Written Discourse Task Helps to Identify Progression from Mild Cognitive Impairment to Dementia

PURPOSE

We aimed to investigate: (1) the clinical, diagnostic value of a written discourse task, and (2) the relationship between executive functions and written discourse within the spectrum of individuals with mild cognitive impairment (MCI).

METHOD

To determine whether written discourse performance predicts clinical course among individuals with MCI, we retrospectively classified individuals with MCI as converters (N = 26) who were later diagnosed with dementia or as a stable MCI group (N = 45). We quantified core word measures from written discourse samples obtained from the Cookie Theft picture description task.

RESULT

Written discourse measures differentiated converters from the stable MCI group. Converters produced a fewer number of core words than the stable MCI group. A measure of executive function significantly predicted performance on the production of core words in written discourse for the converters. In a multivariable regression, production of core words remained the only explanatory variable closely associated with the progression to dementia in MCI.

CONCLUSION

Written discourse tasks can predict the likelihood of MCI progressing to dementia, independently of recall and an executive function measure. Correlational results suggest that written discourse performance was associated with executive function as measured by the Trail Making Test. Our findings emphasize the usefulness of including written discourse tasks in language assessment batteries targeting preclinical dementia populations.

Transcranial Direct-Current Stimulation as an Adjunct to Verb Network Strengthening Treatment in Post-stroke Chronic Aphasia: A Double-Blinded Randomized Feasibility Study

Background

Difficulties in discourse production are common in post-stroke chronic aphasia. Previous studies have found that speech and language therapy combined with transcranial direct-current stimulation (tDCS) may improve language skills like naming and enhance aphasia treatment outcomes. However, very few studies have investigated the effect of tDCS when combined with interventions for improving higher level language skills such as the Verb Network Strengthening Treatment (VNeST).

Aims

This study aimed to determine the feasibility of anodal tDCS as an adjunct to VNeST to improve discourse production in post-stroke chronic aphasia.

Methods

Six people with post-stroke chronic aphasia took part in this double-blinded randomized feasibility study. Participants were randomly allocated to either the experimental group receiving a 6-week block of once weekly VNeST sessions combined with active tDCS over the left inferior frontal gyrus (LIFG) or a control group that received VNeST with sham stimulation. Feasibility outcomes included screening, eligibility, retention, and completion rates, and adverse events. Preliminary response to intervention was also examined using discourse production, functional communication, quality of life, psychological state, and cognition outcomes.

Results

Overall 19 individuals were screened and ten met the inclusion criteria. Six individuals provided consent and participated in the study giving a consent rate of 60%. Participant retention and completion rates were 100% and no adverse effects were reported. Exploratory analyses revealed promising changes (i.e., estimated large effect size) in discourse production measures across discourse language tasks and functional communication for the active tDCS group.

Conclusions

Our results support the feasibility of tDCS as an adjunct to VNeST. Preliminary findings provide motivation for future large-scale studies to better understand the potential of tDCS as a safe and economical tool for enhancing rehabilitation in chronic aphasia.

Are single-word picture naming assessments a valid measure of word retrieval in connected speech?

Purpose: Picture naming assessments are one of the most common methods of examining word retrieval in aphasia. However, currently, it is unclear whether these assessments are able to accurately predict word retrieval in "real-life" communication. This paper aims to explore the evidence in the current literature regarding the relationship between picture naming and word retrieval in connected speech in people with aphasia.Method: Literature was reviewed that examined the correlation between picture naming and word retrieval in connected speech. The literature search was limited to articles that were English language, participants with aphasia, and that were not therapy studies.Result: The existing studies showed mixed findings. However, comparison of study outcomes was complicated by inconsistency in the research methods used, including in word retrieval measures and connected speech elicitation.Conclusion: While there is some evidence of a relationship between picture naming and word retrieval in connected speech, correlation outcomes were mixed with possible influences from participant characteristics, assessment method and speech sample type. We therefore suggest that clinical decision-making would benefit from supplementing picture naming tests with an analysis of word retrieval in connected speech. Further research is required with a focus on natural conversation and the development of standard testing procedures for connected speech.

Picture Description of the Western Aphasia Battery Picnic Scene: Reference Data for the French Canadian Population

PURPOSE

The main aim of this study is to provide French Canadian reference data for quantitative measures extracted from connected speech samples elicited by the Western Aphasia Battery-Revised picnic scene, a discourse task frequently used in clinical assessment of acquired language disorders.

METHOD

Our sample consisted of 62 healthy French Canadian adults divided in two age groups: a 50- to 69-year-old group and a 70- to 90-year-old group.

RESULTS

High interrater reliability scores were obtained for most of the variables. Most connected speech variables did not demonstrate an age effect. However, the 70- to 90-year-old group produced more repetitions than the 50- to 69-year-old group and displayed reduced communication efficiency (number of information content units per minute).

CONCLUSION

These findings contribute to building a reference data set to analyze descriptive discourse production in clinical settings.

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.

Spoken Discourse Assessment and Analysis in Aphasia: An International Survey of Current Practices

Purpose Spoken discourse analysis is commonly employed in the assessment and treatment of people living with aphasia, yet there is no standardization in assessment, analysis, or reporting procedures, thereby precluding comparison/meta-analyses of data and hindering replication of findings. An important first step is to identify current practices in collecting and analyzing spoken discourse in aphasia. Thus, this study surveyed current practices, with the goal of working toward standardizing spoken discourse assessment first in research settings with subsequent implementation into clinical settings. Method A mixed-methods (quantitative and qualitative) survey was publicized to researchers and clinicians around the globe who have collected and/or analyzed spoken discourse data in aphasia. The survey data were collected between September and November 2019. Results Of the 201 individuals who consented to participate, 189 completed all mandatory questions in the survey (with fewer completing nonmandatory response questions). The majority of respondents reported barriers to utilizing discourse including transcription, coding, and analysis. The most common barrier was time (e.g., lack of time). Respondents also indicated that there was a lack of, and a need for, psychometric properties and normative data for spoken discourse use in the assessment and treatment of persons with aphasia. Quantitative and qualitative results are described in detail. Conclusions The current survey study evaluated spoken discourse methods in aphasia across research and clinical settings. Findings from this study will be used to guide development of process standardization in spoken discourse and for the creation of a psychometric and normative property database. Supplemental Material https://doi.org/10.23641/asha.166395100.

Assessing Language in Unstructured Conversation in People With Aphasia: Methods, Psychometric Integrity, Normative Data, and Comparison to a Structured Narrative Task

Purpose This study evaluated interrater reliability (IRR) and test-retest stability (TRTS) of seven linguistic measures (percent correct information units, relevance, subject-verb-[object], complete utterance, grammaticality, referential cohesion, global coherence), and communicative success in unstructured conversation and in a story narrative monologue (SNM) in persons with aphasia (PWAs) and matched participants without aphasia (M-PWoAs). Furthermore, the relationship of language in unstructured conversation and SNM was investigated for these measures. Methods Twenty PWAs and 20 M-PWoAs participated in two unstructured conversations on different days with different speech-language pathologists trained as social conversation partners. An 8- to 12-min segment of each conversation was analyzed. Additionally, a wordless picture book was used to elicit an SNM sample at each visit. Correlational analyses were conducted to address the primary research questions. Normative range and minimal detectable change data were also calculated for the measures in both conditions. Results IRR and TRTS were moderate to good for parametric measures and moderate to excellent for nonparametric measures for both groups, except for TRTS for referential cohesion for the PWAs in conversation. Furthermore, in PWAs, a strong correlation was demonstrated for three of eight measures across conditions. Moderate or weaker correlations were demonstrated for three of eight measures, and correlations for two of eight measures were not significant. An ancillary finding was no significant differences occurred for sample-to-sample variability between the two conditions for any measure. Conclusions This study replicates previous research demonstrating the feasibility to reliably measure language in unstructured conversation in PWAs. Furthermore, this study provides preliminary evidence that language production varies for some measures between unstructured conversation and SNM, contributing to a literature base that demonstrates language variation between different types of monologue. Thus, these findings suggest that inclusion of the specific types of discourse of interest to the PWA may be important for comprehensive assessment of aphasia. Supplemental Material https://doi.org/10.23641/asha.16569360.

A Comparison of Manual Versus Automated Quantitative Production Analysis of Connected Speech

Purpose Analysis of connected speech in the field of adult neurogenic communication disorders is essential for research and clinical purposes, yet time and expertise are often cited as limiting factors. The purpose of this project was to create and evaluate an automated program to score and compute the measures from the Quantitative Production Analysis (QPA), an objective and systematic approach for measuring morphological and structural features of connected speech. Method The QPA was used to analyze transcripts of Cinderella stories from 109 individuals with acute-subacute left hemisphere stroke. Regression slopes and residuals were used to compare the results of manual scoring and automated scoring using the newly developed C-QPA command in CLAN, a set of programs for automatic analysis of language samples. Results The C-QPA command produced two spreadsheet outputs: an analysis spreadsheet with scores for each utterance in the language sample, and a summary spreadsheet with 18 score totals from the analysis spreadsheet and an additional 15 measures derived from those totals. Linear regression analysis revealed that 32 of the 33 measures had good agreement; auxiliary complexity index was the one score that did not have good agreement. Conclusions The C-QPA command can be used to perform automated analyses of language transcripts, saving time and training and providing reliable and valid quantification of connected speech. Transcribing in CHAT, the CLAN editor, also streamlined the process of transcript preparation for QPA and allowed for precise linking of media files to language transcripts for temporal analyses.

Dialectally-sensitive norms of the Spanish version of Main Concept Analysis (Span-MCA) for quantifying neurogenically impaired spoken discourse

Aphasia is an acquired language impairment caused by damage in the regions of the brain that support language. The Main Concept Analysis (MCA; Kong, 2016b) is a published formal assessment battery that allows the quantification of the presence, accuracy, completeness, and efficiency of content in spoken discourse produced by persons with aphasia (PWA). It utilizes a sequential picture description task (with four sets of pictures) for language sample elicitation. The MCA results can also be used clinically for targeting appropriate interventions of aphasic output. The purpose of this research is to develop a Spanish adaptation of the MCA (i.e., Span-MCA) by establishing normative data based on native unimpaired speakers of Spanish from four different dialect origins (Central American Caribbean, Andean-Pacific, Mexican, and Central-Southern Peninsular regions). A total of 91 unimpaired participants that consisted of different age groups, education levels, and dialect origins were recruited to establish four sets of dialect-specific norms and scoring criteria of Span-MCA, including target main concepts and corresponding lexical items related to the picture sets. The Span-MCA was also applied to one pilot native Spanish PWA. The normative data suggested that speakers who were younger or with a higher level of education levels produced significantly more accurate and complete main concepts in their spoken discourse. The application of Span-MCA to the pilot native Spanish PWA successfully identified impaired performance, as compared to the dialectally-sensitive norms established in this study. This study highlighted the clinical value of Span-MCA as a supplement to evaluate spoken discourse and target intervention by speech-language pathologists and related healthcare practitioners.

Standardizing Assessment of Spoken Discourse in Aphasia: A Working Group With Deliverables

Purpose The heterogeneous nature of measures, methods, and analyses reported in the aphasia spoken discourse literature precludes comparison of outcomes across studies (e.g., meta-analyses) and inhibits replication. Furthermore, funding and time constraints significantly hinder collecting test-retest data on spoken discourse outcomes. This research note describes the development and structure of a working group, designed to address major gaps in the spoken discourse aphasia literature, including a lack of standardization in methodology, analysis, and reporting, as well as nominal data regarding the psychometric properties of spoken discourse outcomes. Method The initial initiatives for this working group are to (a) propose recommendations regarding standardization of spoken discourse collection, analysis, and reporting in aphasia, based on the results of an international survey and a systematic literature review and (b) create a database of test-retest spoken discourse data from individuals with and without aphasia. The survey of spoken discourse collection, analysis, and interpretation procedures was distributed to clinicians and researchers involved in aphasia assessment and rehabilitation from September to November 2019. We will publish survey results and recommend standards for collecting, analyzing, and reporting spoken discourse in aphasia. A multisite endeavor to collect test-retest spoken discourse data from individuals with and without aphasia will be initiated. This test-retest information will be contributed to a central site for transcription and analysis, and data will be subsequently openly curated. Conclusion The goal of the working group is to create recommendations for field-wide standards in methods, analysis, and reporting of spoken discourse outcomes, as has been done across other related disciplines (e.g., Consolidated Standards of Reporting Trials, Enhancing the Quality and Transparency of Health Research, Committee on Best Practice in Data Analysis and Sharing). Additionally, the creation of a database through our multisite collaboration will allow the identification of psychometrically sound outcome measures and norms that can be used by clinicians and researchers to assess spoken discourse abilities in aphasia.

Measuring Global Coherence in People With Aphasia During Unstructured Conversation

Purpose Global coherence is an essential macrolinguistic discourse skill that speakers use to formulate discourse to convey meaning with maintenance to a topic. When global coherence is poor, the listener's ability to understand how the discourse makes sense as a whole is diminished. Measures exist to evaluate global coherence in people with aphasia during monologue tasks (e.g., picture description). The aim of the current research is to develop such a measure for unstructured conversation and to explore how global coherence is impacted by aphasia during conversation. A global coherence measure for conversation is required because markedly different cognitive and linguistic demands are made for production of different types of discourse. Thus, a structured monologue measure cannot be used with validity for unstructured conversation. To adequately evaluate global coherence during conversation, a measure specific to the demands of conversation is required. Method We adapted the 4-point Global Coherence Scale (Wright & Capilouto, 2012; Wright et al., 2013), a monologue-level measure of global coherence to conversation, resulting in the 4-point Global Coherence Scale in unstructured conversation (GCSconv). We conducted statistical evaluation of the reliability/stability of the 4-point GCSconv in 18 unstructured conversations held by nine people with aphasia. Utterances with low global coherence scores were classified following a recent methodology to describe how breakdown in these utterances contributed to diminished global coherence (Hazamy & Obermeyer, 2019). Results The 4-point GCSconv demonstrated excellent inter/intrarater reliability and test-retest stability. Nonspecific language and off-topic comments contributed most frequently to lowered global coherence. Conclusions Findings suggest the 4-point GCSconv may be a feasible and reliable measure of global coherence in conversation. This measure adds to a core of emerging reliable discourse measures for conversation. As such, it has potential to inform assessment and treatment of everyday conversation and to investigate the relationship of global coherence in structured monologue and unstructured conversation. Supplemental Material https://doi.org/10.23641/asha.12469187.

Creating a Theoretical Framework to Underpin Discourse Assessment and Intervention in Aphasia

Discourse (a unit of language longer than a single sentence) is fundamental to everyday communication. People with aphasia (a language impairment occurring most frequently after stroke, or other brain damage) have communication difficulties which lead to less complete, less coherent, and less complex discourse. Although there are multiple reviews of discourse assessment and an emerging evidence base for discourse intervention, there is no unified theoretical framework to underpin this research. Instead, disparate theories are recruited to explain different aspects of discourse impairment, or symptoms are reported without a hypothesis about the cause. What is needed is a theoretical framework that would clarify the specific linguistic skills that create completeness, coherence, and complexity (i.e., richness) in discourse, and illuminate both the processes involved in discourse production and the reasons for breakdown. This paper reports a review and synthesis of the theoretical literature relevant to spoken discourse in aphasia discourse, and we propose a novel theoretical framework which unites these disparate sources. This framework is currently being tested as the foundation for Linguistic Underpinnings of Narrative in Aphasia (LUNA) treatment research. In this paper, we outline the novel framework and exemplify how it might be used to guide clinical practice and research. Future collaborative research is needed to develop this framework into a processing model for spoken discourse.

Breakdowns in Informativeness of Naturalistic Speech Production in Primary Progressive Aphasia

“Functional communication” refers to an individual’s ability to communicate effectively in his or her everyday environment, and thus is a paramount skill to monitor and target therapeutically in people with aphasia. However, traditional controlled-paradigm assessments commonly used in both research and clinical settings often fail to adequately capture this ability. In the current study, facets of functional communication were measured from picture-elicited speech samples from 70 individuals with mild primary progressive aphasia (PPA), including the three variants, and 31 age-matched controls. Building upon methods recently used by Berube et al. (2019), we measured the informativeness of speech by quantifying the content of each patient’s description that was relevant to a picture relative to the total amount of speech they produced. Importantly, form-based errors, such as mispronunciations of words, unusual word choices, or grammatical mistakes are not penalized in this approach. We found that the relative informativeness, or efficiency, of speech was preserved in non-fluent variant PPA patients as compared with controls, whereas the logopenic and semantic variant PPA patients produced significantly less informative output. Furthermore, reduced informativeness in the semantic variant is attributable to a lower production of content units and a propensity for self-referential tangents, whereas for the logopenic variant, a lower production of content units and relatively ”empty” speech and false starts contribute to this reduction. These findings demonstrate that functional communication impairment does not uniformly affect all the PPA variants and highlight the utility of naturalistic speech analysis for measuring the breakdown of functional communication in PPA.

Main Concept, Sequencing, and Story Grammar Analyses of Cinderella Narratives in a Large Sample of Persons with Aphasia

Recently, a multilevel analytic approach called Main Concept, Sequencing, and Story Grammar (MSSG) was presented along with preliminary normative information. MSSG analyses leverage the strong psychometrics and rich procedural knowledge of both main concept analysis and story grammar component coding, complementing it with easy-to-obtain sequencing information for a rich understanding of discourse informativeness and macrostructure. This study is the next critical step for demonstrating the clinical usefulness of MSSG’s six variables (main concept composite, sequencing, main concept+sequencing, essential story grammar components, total episodic components, and episodic complexity) for persons with aphasia (PWAs). We present descriptive statistical information for MSSG variables for a large sample of PWAs and compare their performance to a large sample of persons not brain injured (PNBIs). We observed significant differences between PWAs and PNBIs for all MSSG variables. These differences occurred at the omnibus group level and for each aphasia subtype, even for PWAs with very mild impairment that is not detected with standardized aphasia assessment. Differences between PWAs and PNBIs were also practically significant, with medium to large effect sizes observed for nearly all aphasia subtypes and MSSG variables. This work deepens our understanding of discourse informativeness and macrostructure in PWAs and further develops an efficient tool for research and clinical use. Future research should investigate ways to expand MSSG analyses and to improve sensitivity and specificity.

Making Sense of Right Hemisphere Discourse Using RHDBank

PURPOSE

Right hemisphere brain damage (RHD) commonly causes pragmatic language disorders that are apparent in discourse production. Specific characteristics and approaches to assessment, diagnosis, and treatment of these disorders are not well-defined. RHDBank, a shared database of multimedia interactions for the study of communication using discourse, was created to address these gaps. The database, materials, and related analysis programs are free resources to clinicians, researchers, educators, and students.

METHOD

A standard discourse protocol was developed to elicit multiple types of discourse: free speech, conversation, picture description, storytelling, procedural discourse, and question-asking. Testing included measures of cognition, unilateral neglect, and communicative participation. Language samples were video-recorded and transcribed in CHAT format. Currently, the database includes 24 adults with RHD and 24 controls.

RESULTS

Illustrative analyses show how RHDBank can facilitate research using micro- and macrolinguistic discourse analysis techniques both within this population and across populations. Educational resources, such as the Grand Rounds tutorial, were developed using case studies from the database.

CONCLUSIONS

RHDBank is a shared database of resources that can facilitate educational and research efforts to address the gaps in knowledge about RHD communication and improve the clinical management of individuals with RHD.

Automation of the Northwestern Narrative Language Analysis System

Purpose Analysis of spontaneous speech samples is important for determining patterns of language production in people with aphasia. To accomplish this, researchers and clinicians can use either hand coding or computer-automated methods. In a comparison of the two methods using the hand-coding NNLA (Northwestern Narrative Language Analysis) and automatic transcript analysis by CLAN (Computerized Language Analysis), Hsu and Thompson (2018) found good agreement for 32 of 51 linguistic variables. The comparison showed little difference between the two methods for coding most general (i.e., utterance length, rate of speech production), lexical, and morphological measures. However, the NNLA system coded grammatical measures (i.e., sentence and verb argument structure) that CLAN did not. Because of the importance of quantifying these aspects of language, the current study sought to implement a new, single, composite CLAN command for the full set of 51 NNLA codes and to evaluate its reliability for coding aphasic language samples. Method Eighteen manually coded NNLA transcripts from eight people with aphasia and 10 controls were converted into CHAT (Codes for the Human Analysis of Talk) files for compatibility with CLAN commands. Rules from the NNLA manual were translated into programmed rules for CLAN computation of lexical, morphological, utterance-level, sentence-level, and verb argument structure measures. Results The new C-NNLA (CLAN command to compute the full set of NNLA measures) program automatically computes 50 of the 51 NNLA measures and generates the results in a summary spreadsheet. The only measure it does not compute is the number of verb particles. Statistical tests revealed no significant difference between C-NNLA results and those generated by manual coding for 44 of the 50 measures. C-NNLA results were not comparable to manual coding for the six verb argument measures. Conclusion Clinicians and researchers can use the automatic C-NNLA to analyze important variables required for quantification of grammatical deficits in aphasia in a way that is fast, replicable, and accessible without extensive linguistic knowledge and training.

UK speech and language therapists' views and reported practices of discourse analysis in aphasia rehabilitation

BACKGROUND

Discourse assessment and treatment in aphasia rehabilitation is a priority focus for a range of stakeholder groups. However, a significant majority of speech and language therapists (SLTs) infrequently conduct discourse analysis, and do not feel competent in doing so. Known barriers identified in other countries, specifically a lack of time, training, expertise and resources, affect use of discourse analysis in clinical practice.

AIMS

To investigate UK SLTs' reported practices and views of discourse analysis, barriers and facilitators, and clinical feasibility in aphasia rehabilitation.

METHODS & PROCEDURES

An online survey of 52 questions adapted from existing research and incorporating behaviour change literature was created for the study and piloted. UK SLTs working in aphasia rehabilitation for at least 6 months were invited to participate. Potential participants were contacted through national and local clinical excellence networks, a National Health Service (NHS) bespoke e-mail list, and national magazine advertisement, and the study was also advertised on social media (Twitter). Therapists read an online participant information sheet and submitted individual electronic consent online; then progressed to the Qualtrics survey. Descriptive, correlational and inferential statistical analyses were conducted, and content analysis was carried out on the questions requiring text.

OUTCOMES & RESULTS

A total of 211 valid responses were received from primarily female SLTs, aged 20-40 years, working full-time in the NHS in England, in community, inpatient and acute/subacute multidisciplinary settings. A total of 30% SLTs collected discourse analysis often, were mostly very experienced, and working part-time in community settings. Years of experience was predictive of use. Discourse was most often collected using standardized picture descriptions and recounts during initial assessment. Samples were infrequently recorded, and typically transcribed in real-time. Most SLTs (53-95%) reported making clinical judgements or manually counted words, sentences, communication of ideas and errors, and were confident in doing so. Barriers included time constraints; lack of expertise, confidence, training, resources and equipment; and patient severity. Discourse 'super-users' were distinguished by significantly higher professional motivation for discourse and workplace opportunity than other SLTs, and 'non-users' were distinguished by significantly less knowledge and skills in discourse analysis than other SLTs. SLTs reported a desire and need for training, new/assistive tools and time to do more discourse analysis in practice.

CONCLUSIONS & IMPLICATIONS

Clinicians were highly engaged and relatively active in at least some aspects of discourse analysis practice. Interventions that target individual clinicians as well as organizations and systems are needed to improve the uptake of discourse analysis in practice. What this paper adds What is already known on the subject? Discourse in aphasia rehabilitation is a priority in clinical practice and research. However, the majority of clinicians infrequently collect and analyse discourse. Research in Australia and the United States indicated that lack of time, assessment resources and relevant knowledge and skills are the main barriers to use. What this paper adds to existing knowledge Compared with existing research, UK SLTs were more likely to see discourse analysis as part of their role and experienced fewer barriers, and more SLTs did it at least sometimes in clinic. However, practices were limited by lack of training, giving rise to challenges in selecting and interpreting findings for clients. More use was predicted by more experience and commitment to discourse analysis, particularly where workplaces supported this approach. Less use was associated with less knowledge and skills in discourse analysis. Practice and decision-making were influenced by client factors and constrained to a lesser degree by logistical challenges. What are the potential or actual clinical implications of this study? Education and training in discourse analyses and in specific procedures are needed to improve individual clinicians' knowledge, skills and confidence in using discourse analysis for clients' rehabilitation. Equally, organizational and systems changes are needed to promote, support and reinforce discourse analysis in the workplace.

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.

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.

Impact of Combined Transcranial Direct Current Stimulation and Speech-language Therapy on Spontaneous Speech in Aphasia: A Randomized Controlled Double-blind Study

OBJECTIVE

Aphasia recovery depends on neural reorganization, which can be enhanced by speech-language therapy and noninvasive brain stimulation. Several studies suggested that transcranial direct current stimulation (tDCS) associated with speech-language therapy may improve verbal performance evaluated by analytic tests, but none focused on spontaneous speech. We explored the effect of bihemispheric tDCS on spontaneous speech in patients with poststroke aphasia.

METHODS

In this multicentric controlled randomized cross-over double-blind study, we included 10 patients with poststroke aphasia (4 had aphasia >6 months and 6 with aphasia <6 months). We combined the sessions of speech-language therapy and bihemispheric tDCS (2 mA, 20 min). After three baseline speech evaluations (1/week), two different conditions were randomly consecutively proposed: active and sham tDCS over 3 weeks with 1 week of washout in between. The main outcome measure was the number of different nouns used in 2 min to answer the question "what is your job."

RESULTS

There was no significant difference between conditions concerning the main outcome measure (p = .47) nor in the number of verbs, adjectives, adverbs, pronouns, repetitions, blank ideas, ideas, utterances with grammatical errors or paraphasias used. Other cognitive functions (verbal working memory, neglect, or verbal fluency) were not significantly improved in the tDCS group. No adverse events occurred.

CONCLUSION

Our results differed from previous studies using tDCS to improve naming in patients with poststroke aphasia possibly due to bihemispheric stimulation, rarely used previously. The duration of the rehabilitation period was short given the linguistic complexity of the measure. This negative result should be confirmed by larger studies with ecological measures.

Evaluating informative content and global coherence in fluent and non-fluent aphasia

BACKGROUND

Discourse analysis is an important component of aphasia assessment because it can provide an insight into functional communication abilities. However, there are many unknowns regarding the levels of discourse breakdowns that occur across aphasia types. The purpose of the current study is to explore the possible differences in discourse-level communication in persons with fluent and non-fluent aphasia during picture description.

AIMS

To examine if persons with fluent and non-fluent aphasia differ on utterance-level discourse measures when evaluating informative content and global coherence. Additionally, to evaluate and compare the types of global coherence violations made by each group.

METHODS & PROCEDURES

Data from 31 people with aphasia was collected from AphasiaBank, which included 13 people with fluent aphasia and 18 people with non-fluent aphasia. Discourse samples from three picture descriptions were analysed. Discourse outcomes included utterances with new information (UNIs-relevant utterances containing new information) and global coherence (the extent to which each utterance maintained the overall discourse theme). Additionally, seven types of errors were identified to explore the nature of breakdowns in global coherence.

OUTCOMES & RESULTS

People with fluent aphasia produced significantly higher proportions of UNIs and had significantly higher average global coherence ratings than those with non-fluent aphasia. Differences in global coherence violations were identified with people with fluent aphasia producing more non-specific, incorrect and off-topic utterances and people with non-fluent aphasia producing more incomplete utterances. One of the most common global coherence error types in both groups was commentary.

CONCLUSIONS & IMPLICATIONS

Although people with fluent aphasia produced more types of global coherence errors, including incorrect, non-specific and off-topic utterances, the group was still rated significantly higher on utterance relevance and topic maintenance, indicating that the ability to produce a complete utterance plays an important role in some aspects of discourse production. Additionally, these findings provide an insight into potential targets for intervention.

Revisiting the Correct Information Unit: Measuring Informativeness in Unstructured Conversations in People With Aphasia

Purpose The purpose of this study was to determine whether the correct information unit (CIU) can be reliably applied to unstructured conversational discourse in people with aphasia (PWA). The CIU was developed by Nicholas and Brookshire (1993) to measure word-level informativeness in structured monologue-level discourse and is widely used by clinicians and researchers for this purpose. A case study (Oelschlaeger & Thorne, 1999) investigating the use of the CIU in conversation has suggested potential issues with interrater reliability (IRR), which has discouraged application of the CIU to this discourse context. However, no further research has been conducted to replicate or extend this finding. Given a clinical and research need for reliable linguistic measures appropriate for use in unstructured conversation, revisiting the reliability, stability, and suitability of the CIU is indicated. Method The CIU protocol developed by Nicholas and Brookshire (1993) was modified according to the needs of conversational discourse, resulting in the CIU in conversation (CIUconv) protocol. Two speech-language pathology graduate student research assistants completed training on use of the CIUconv with the 1st author. Sixteen conversations held by 8 PWA (i.e., 2 conversations each) were used as language samples to determine IRR of percent CIU (%CIU) in conversation through use of the CIUconv. Test-retest stability of %CIU as applied per this protocol was then assessed across the 2 conversations collected for each PWA. Results Use of the CIUconv resulted in excellent IRR of %CIU for each research assistant and the 1st author. Likewise, test-retest stability for the measure was excellent. Results were evaluated at both the group and individual levels. Conclusions %CIU demonstrated excellent interrater and test-retest reliability when applied to unstructured conversation using the CIUconv procedure, which was developed to account for expected linguistic characteristics of conversation. These findings suggest that %CIU may be a feasible, reliable measure of informativeness in unstructured conversation in PWA when the CIUconv is used by trained raters.

Evaluating Personal Stroke Narratives from Bilingual Greek-English Immigrants with Aphasia

OBJECTIVE

For people with aphasia (PWA) and their significant others, narratives are intricately intertwined with quality of life, culture, and social participation. This paper reports stories told by bilingual people with aphasia (bPWA), describing the events or consequences of a stroke on their lives.

PATIENTS AND METHODS

Six participants with chronic mild-moderate anomia (mean age 70 years) spontaneously produced a narrative recounting their personal experience of stroke in their native language (Greek) and in their second language (English). All bPWA had learned English in early adulthood upon migration from Greece to Australia, not through formal teaching but on the job (e.g., in the factory). The bPWA had lived in Australia for 46 years (average) and were less than 4 years post-stroke.

RESULTS

Narratives in the two languages underwent quantitative (number of propositions, noun/verb tokens) and qualitative analyses (ratings of coherence, ratings of clarity). Most bPWA produced coherent "tellable" stories despite disruptions in language because of aphasia. Overall, stories were better told (length, complexity of content, temporal-causal sequencing, reference) in Greek - their native language.

CONCLUSION

The results have implications for policy-makers providing health and welfare services to ageing immigrant populations. The findings are also relevant to other countries that have large immigrant populations of stroke survivors.

Conversation in Aphasia Across Communication Partners: Exploring Stability of Microlinguistic Measures and Communicative Success

Purpose The aim of this study was to determine if people with aphasia demonstrate differences in microlinguistic skills and communicative success in unstructured, nontherapeutic conversations with a home communication partner (Home-P) as compared to a speech-language pathologist communication partner (SLP-P). Method Eight persons with aphasia participated in 2 unstructured, nontherapeutic 15-minute conversations, 1 each with an unfamiliar SLP-P and a Home-P. Utterance-level analysis evaluated communicative success. Two narrow measures of lexical relevance and sentence frame were used to evaluate independent clauses. Two broad lexical and morphosyntactic measures were used to evaluate elliptical and dependent clauses and to evaluate independent clauses for errors beyond lexical relevance and sentence frame (such as phonological and morphosyntactic errors). Utterances were further evaluated for presence of behaviors indicating lexical retrieval difficulty (pauses, repetitions, and false starts) and for referential cohesion. Results No statistical differences occurred for communicative success or for any of the microlinguistic measures between the SLP-P and Home-P conversation conditions. Four measures (2 of lexical retrieval and 1 each of communicative success and grammaticality) showed high correlations across the 2 conversation samples. Individuals showed variation of no more than 10 percentage points between the 2 conversation conditions for 46 of 56 data points. Variation greater than 10 percentage points tended to occur for the measure of referential cohesion and primarily for 1 participant. Conclusions Preliminary findings suggest that these microlinguistic measures and communicative success have potential for reliable comparison across Home-P and SLP-P conversations, with the possible exception of referential cohesion. However, further research is needed with a larger, more diverse sample. These findings suggest future assessment and treatment implications for clinical and research needs. Supplemental Material https://doi.org/10.23641/asha.7616312.

A Large-Scale Comparison of Main Concept Production Between Persons With Aphasia and Persons Without Brain Injury

Purpose The purposes of this study are to provide clinicians and researchers with introductory psychometric data for the main concept analysis (MCA), a measure of discourse informativeness, and specifically, to provide descriptive and comparative statistical information about the performance of a large sample of persons not brain injured (PNBIs) and persons with aphasia (PWAs) on AphasiaBank discourse tasks. Method Transcripts of 5 semi-spontaneous discourse tasks were retrieved from the AphasiaBank database and scored according to detailed checklists and scoring procedures. Transcripts from 145 PNBIs and 238 PWAs were scored; descriptive statistics, median tests, and effect sizes are reported. Results PWAs demonstrated overall lower informativeness scores and more frequent production of statements that were inaccurate and/or incomplete. Differences between PNBIs and PWAs were observed for all main concept measures and stories. Comparisons of PNBIs and aphasia subtypes revealed significant differences for all groups, although the pattern of differences and strength of effect sizes varied by group and discourse task. Conclusions These results may improve the investigative and clinical utility of the MCA by providing descriptive and comparative information for PNBIs and PWAs for standardized discourse tasks that can be reliably scored. The results indicate that the MCA is sensitive to differences in discourse as a result of aphasia. Supplemental Material https://doi.org/10.23641/asha.7485647.

Main concepts for two picture description tasks: An addition to

BACKGROUND

Proposition analysis of the discourse of persons with aphasia has a long history, yielding important advancements in our understanding of communication impairments in this population. Recently, discourse measures have been considered primary outcome measures, and multiple calls have been made for improved psychometric properties of discourse measures.

AIMS

To advance the use of discourse analysis in persons with aphasia by providing Main Concept Analysis checklists and descriptive statistics for healthy control performance on the analysis for the Cat in the Tree and Refused Umbrella narrative tasks utilized in the AphasiaBank database protocol.

METHODS & PROCEDURES

Ninety-two control transcripts, stratified into four age groups (20-39 years; 40-59; 60-79; 80+), were downloaded from the AphasiaBank database. Relevant concepts were identified, and those spoken by at least one-third of the control sample were considered to be a main concept. A multi-level coding system was used to determine the accuracy and completeness of the main concepts produced by control speakers.

OUTCOMES & RESULTS

Main concept checklists for two discourse tasks are provided. Descriptive statistics are reported and examined to assist readers with evaluation of the normative data.

CONCLUSIONS

These checklists provide clinicians and researchers with a tool to reliably assess the discourse of persons with aphasia. They also help address the gap in available psychometric data with which to compare persons with aphasia to healthy controls.

Psychometric properties of discourse measures in aphasia: acceptability, reliability, and validity

BACKGROUND

Discourse in adults with aphasia is increasingly the focus of assessment and therapy research. A broad range of measures is available to describe discourse, but very limited information is available on their psychometric properties. As a result, the quality of these measures is unknown, and there is very little evidence to motivate the choice of one measure over another.

AIMS

To explore the quality of a range of discourse measures, targeting sentence structure, coherence, story structure and cohesion. Quality was evaluated in terms of the psychometric properties of acceptability (data completeness and skewness), reliability (inter- and intra-rater), and validity (content, convergent, discriminant and known groups).

METHODS & PROCEDURES

Participants with chronic mild-to-moderate aphasia were recruited from community groups. They produced a range of discourses which were grouped into Cinderella and everyday discourses. Discourses were then transcribed orthographically and analyzed using macro- and microlinguistic measures (Story Grammar, Topic Coherence, Local Coherence, Reference Chains and Predicate Argument Structure-PAS). Data were evaluated against standard predetermined criteria to ascertain the psychometric quality of the measures.

OUTCOMES & RESULTS

A total of 17 participants took part in the study. All measures had high levels of acceptability, inter- and intra-rater reliability, and had good content validity, as they could be related to a level of the theoretical model of discourse production. For convergent validity, as expected, 8/10 measures correlated with the Western Aphasia Battery-Revised (WAB-R) spontaneous speech scores, and 7/10 measures correlated with the Kissing and Dancing Test (KDT) scores (r ≥ 0.3), giving an overall positive rating for construct validity. For discriminant validity, as predicted, all measures had low correlations with Raven's Coloured Progressive Matrices (RCPM) and WAB-R Auditory Verbal Comprehension scores (r < 0.3), giving an overall positive rating for construct validity. Finally, for known groups validity, all measures indicated a difference between speakers with mild and moderate aphasia except for the Local Coherence measures. Overall, Story Grammar, Topic Coherence, Reference Chains and PAS emerged as the strongest measures in the current study because they achieved the predetermined thresholds for quality in terms of each of the psychometric parameters profiled.

CONCLUSIONS & IMPLICATIONS

The current study is the first to psychometrically profile measures of discourse in aphasia. It contributes to the field by identifying Story Grammar, Topic Coherence, Reference Chains and PAS as the most psychometrically robust discourse measures yet profiled with speakers with aphasia. Until further data are available indicating the strength of other discourse measures, caution should be applied when using them.

Information Content and Efficiency in the Spoken Discourse of Individuals With Parkinson's Disease

PURPOSE

This study compared the information content and information efficiency of spoken language in individuals with Parkinson's disease (PD) to a healthy comparator group.

METHOD

Nineteen participants with PD and 19 healthy older adults completed the prospective, cross-sectional study. In the primary analysis, 2 language samples elicited by standardized protocols were analyzed for group differences using standard discourse informativeness measures including main events (MEs; Wright, Capilouto, Wagovich, Cranfill, & Davis, 2005) analyzed as %MEs and correct information units (CIUs; Nicholas & Brookshire, 1993) analyzed as %CIUs and CIUs/min. In exploratory analyses, the following were examined: (a) associations among conceptual (%MEs) and lexical (%CIUs and CIUs/min) measures and (b) associations among informativeness measures and age, education, disease severity/duration, global cognition, speech intelligibility, and a verb confrontation naming measure.

RESULTS

In the primary analysis, the PD group differed significantly from the control group on conceptual (%MEs) and lexical measures of content (%CIUs) and efficiency (CIUs/min). In exploratory analyses, for the control group %MEs were significantly correlated with CIUs/min. Significant associations among conceptual and lexical measures of informativeness were not found in the PD group. For controls, there were no significant correlations between informativeness measures and any of the demographic or speech/cognitive/language variables. In the PD group, there was a significant and positive association between CIUs/min and Dementia Rating Scale-Second Edition scores (Mattis, 2001). A significant but negative correlation was found between CIUs/min and motor severity scores. However, %MEs and verb naming were significantly and positively correlated.

CONCLUSIONS

Individuals with PD without dementia demonstrated reduced discourse informativeness that reflects disruptions to both conceptual and lexical discourse processes. In exploratory analyses, reduced efficiency of information content was associated with global cognition and motor severity. Clinical and research implications are discussed within a Cognitivist framework of discourse production (Sheratt, 2007).