Productive vocabulary across discourse types

A Methodological Approach to Quantifying Silent Pauses, Speech Rate, and Articulation Rate across Distinct Narrative Tasks: Introducing the Connected Speech Analysis Protocol (CSAP)

The examination of connected speech may serve as a valuable tool for exploring speech output in both healthy speakers and individuals with language disorders. Numerous studies incorporate various fluency and silence measures into their analyses to investigate speech output patterns in different populations, along with the underlying cognitive processes that occur while speaking. However, methodological inconsistencies across existing studies pose challenges in comparing their results. In the current study, we introduce CSAP (Connected Speech Analysis Protocol), which is a specific methodological approach to investigate fluency metrics, such as articulation rate and speech rate, as well as silence measures, including silent pauses' frequency and duration. We emphasize the importance of employing a comprehensive set of measures within a specific methodological framework to better understand speech output patterns. Additionally, we advocate for the use of distinct narrative tasks for a thorough investigation of speech output in different conditions. We provide an example of data on which we implement CSAP to showcase the proposed pipeline. In conclusion, CSAP offers a comprehensive framework for investigating speech output patterns, incorporating fluency metrics and silence measures in distinct narrative tasks, thus allowing a detailed quantification of connected speech in both healthy and clinical populations. We emphasize the significance of adopting a unified methodological approach in connected speech studies, enabling the integration of results for more robust and generalizable conclusions.

Investigating silent pauses in connected speech: integrating linguistic, neuropsychological, and neuroanatomical perspectives across narrative tasks in post-stroke aphasia

Introduction

Silent pauses are regarded as integral components of the temporal organization of speech. However, it has also been hypothesized that they serve as markers for internal cognitive processes, including word access, monitoring, planning, and memory functions. Although existing evidence across various pathological populations underscores the importance of investigating silent pauses' characteristics, particularly in terms of frequency and duration, there is a scarcity of data within the domain of post-stroke aphasia.

Methods

The primary objective of the present study is to scrutinize the frequency and duration of silent pauses in two distinct narrative tasks within a cohort of 32 patients with chronic post-stroke aphasia, in comparison with a control group of healthy speakers. Subsequently, we investigate potential correlation patterns between silent pause measures, i.e., frequency and duration, across the two narrative tasks within the patient group, their performance in neuropsychological assessments, and lesion data.

Results

Our findings showed that patients exhibited a higher frequency of longer-duration pauses in both narrative tasks compared to healthy speakers. Furthermore, within-group comparisons revealed that patients tended to pause more frequently and for longer durations in the picture description task, while healthy participants exhibited the opposite trend. With regard to our second research question, a marginally significant interaction emerged between performance in semantic verbal fluency and the narrative task, in relation to the location of silent pauses-whether between or within clauses-predicting the duration of silent pauses in the patient group. However, no significant results were observed for the frequency of silent pauses. Lastly, our study identified that the duration of silent pauses could be predicted by distinct Regions of Interest (ROIs) in spared tissue within the left hemisphere, as a function of the narrative task.

Discussion

Overall, this study follows an integrative approach of linguistic, neuropsychological and neuroanatomical data to define silent pauses in connected speech, and illustrates interrelations between cognitive components, temporal aspects of speech, and anatomical indices, while it further highlights the importance of studying connected speech indices using different narrative tasks.

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.

The contribution of discursive and cognitive factors in referential choices made by elderly people during a narrative task

The present study focuses on referential choices made by healthy aged adults during narrative discourse, and their relationship with cognitive and socio-cognitive abilities. Previously, some studies have shown that, compared to young adults, older adults produce more pronouns when referring to various entities during discourse, regardless of the accessibility level of the referent for the addressee. This referential behavior has been interpreted in relation to the decrease of cognitive abilities, such as working memory abilities. There is, as of yet, little empirical evidence highlighting which cognitive competences preferentially support referential choices during discourse production. Here, we focus on three categories of referential markers (indefinite, definite markers and pronouns) produced by 78 participants from 60 to 91 years old. We used a storytelling task enabling us to examine the referential choices made at three discourse stages (introduction, maintaining or shift of the referent in focus) and in increasing levels of referential complexity (one vs two characters, and different vs same gender). In addition to specifically assessing how increasing age influences referential choices, we also examine the contribution of various cognitive and socio-cognitive skills that are presumed to play a specific role in referential choices. We found that both age and specific cognitive abilities (planification, inhibition, and verbal episodic memory) had an effect on referential choices, but that these effects depended on when (at which discourse stage) the referential markers were produced. Overall, our study highlights the complex interplay between discursive and cognitive factors in referential choices made by healthy older speakers.

Impaired discourse content in aphasia is associated with frontal white matter damage

Aphasia is a common consequence of stroke with severe impacts on employability, social interactions and quality of life. Producing discourse-relevant information in a real-world setting is the most important aspect of recovery because it is critical to successful communication. This study sought to identify the lesion correlates of impaired production of relevant information in spoken discourse in a large, unselected sample of participants with post-stroke aphasia. Spoken discourse (n = 80) and structural brain scans (n = 66) from participants with aphasia following left hemisphere stroke were analysed. Each participant provided 10 samples of spoken discourse elicited in three different genres, and 'correct information unit' analysis was used to quantify the informativeness of speech samples. The lesion correlates were identified using multivariate lesion-symptom mapping, voxel-wise disconnection and tract-wise analyses. Amount and speed of relevant information were highly correlated across different genres and with total lesion size. The analyses of lesion correlates converged on the same pattern: impaired production of relevant information was associated with damage to anterior dorsal white matter pathways, specifically the arcuate fasciculus, frontal aslant tract and superior longitudinal fasciculus. Damage to these pathways may be a useful biomarker for impaired informative spoken discourse and informs development of neurorehabilitation strategies.

Semantic Aspects of Verb Production in Various Discourse Tasks in People With Nonfluent Aphasia

PURPOSE

The purpose of this study was to investigate how people with nonfluent aphasia produce semantically weighted verbs compared to people without aphasia, as well as how a discourse elicitation task affects verb production in people with nonfluent aphasia and people without aphasia.

METHOD

This study included 30 people with nonfluent aphasia and 32 age-matched people without aphasia from AphasiaBank. Language samples of five different discourse tasks were obtained and coded for heavy, light, and be-copular verbs. The number of verbs per utterance and the proportion of heavy, light, and be-copular verbs were compared between groups and between tasks.

RESULTS

People with nonfluent aphasia showed a similar proportion of heavy verbs but reduced verbs per utterance and proportion of light verbs compared to people without aphasia. With regard to discourse task effects, we found a trend for a higher proportion of heavy verbs in sequential picture descriptions, and a higher proportion of be-copular verbs and lower proportion of heavy verbs for a recount compared to other tasks in people without aphasia. The discourse task effects were minimally found in people with nonfluent aphasia.

CONCLUSIONS

Our results suggest that people with nonfluent aphasia present with relatively preserved heavy verb production but with impaired production of light verbs in discourse. In addition, it appears that discourse tasks do not significantly influence the type of verbs produced by people with nonfluent aphasia possibly due to the floor effects and wide range of individual variability. This study is a preliminary effort to evaluate methodological factors that impact verb production; future studies are needed to develop a framework for clinical decision making when selecting a discourse elicitation task for people with aphasia.

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.

Identifying an Appropriate Picture Stimulus for a Bangla Picture Description Task

PURPOSE

The absence of culture- and language-specific aphasia assessment in Bangla underscores a critical problem in communication sciences and disorders. Aphasia occurs in ~41% of Bangla-speaking stroke survivors. In the past 40 years, stroke incidence has doubled in low- and middle-income countries, such as Bangladesh and India, where there are ~250 million native Bangla speakers. This study aims to initiate the first step toward identifying an appropriate picture stimulus for the Bangla picture description task (PDT) intended for inclusion in a Bangla aphasia assessment. Researchers have reported the importance of cultural relevance and three visuographic variables of a picture (high-context, color, and photograph vs. black-and-white line drawing) for faster comprehension and comprehensive language production in people with aphasia and neurologically healthy adults.

METHOD

Ninety-six neurologically healthy native Bangla speakers of three age groups (young 19-30, middle age 40-55, and older 65-89 years) were recruited to compare spontaneous language production for four selected culturally related and nonrelated picture stimuli with and without the three visuographic variables. Five linguistic variables were used to analyze the language samples.

RESULTS

The results demonstrated a significant (a) picture type effect for moving-average type-token ratio, words per minute (WPM), and mean length of utterance in morphemes (MLU) and (b) age group effect for WPM, MLU, and complexity index.

CONCLUSIONS

This study suggests that a culturally related high-context color photograph is the optimal choice for the Bangla PDT. This study also indicates reduced fluency, grammatical complexity, and syntactic complexity in healthy Bangla-speaking adults aged 65 years and above.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22233664.

Validation of Videoconference Administration of Picture Description From the Western Aphasia Battery-Revised in Neurotypical Canadian French Speakers

PURPOSE

During the COVID-19 pandemic, clinicians and researchers have increasingly used remote online assessments to pursue their activities, but mostly with tests not validated for videoconference administration. This study aims to validate the remote online administration of picture description in Canadian French neurotypical speakers and to explore the thematic unit (TU) checklist recently developed.

METHOD

Spoken discourse elicited through the picture description task of the Western Aphasia Battery-Revised (WAB-R) was collected from Canadian French neurotypical speakers from Québec aged between 50 and 79 years old. Forty-seven participants completed the task in person, and 49 participants completed the task by videoconference. Videos of each discourse sample were transcribed using CHAT conventions. Microstructural variables were extracted using the CLAN (Computerized Language ANalysis) program, whereas thematic informativeness was scored for each sample using TUs. Chi-square tests were conducted to compare both groups on each TU; t tests were also performed on the total score of TUs and microstructural variables.

RESULTS

Groups were matched on sex, age, and education variables. The t tests revealed no intergroup difference for the total TU score and for the microstructural variables (e.g., mean length of utterances and number of words per minute). Chi-square tests showed no significant intergroup difference for all 16 TUs.

CONCLUSIONS

These findings support remote online assessment of the picnic scene of the WAB-R picture description in Canadian French neurotypical speakers. These results also validate the 16 TUs most consistently produced. The use of videoconference could promote and improve the recruitment of participants who are usually less accessible, such as people using assistive mobility technologies.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21476961.

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.

Light verb production in healthy ageing and dementia

BACKGROUND

Light verbs are highly frequent and semantically impoverished words. It is currently not known whether light verb production in discourse tasks differs by age or for people with dementia of the Alzheimer's type (DAT).

AIMS

The purpose of the current study was two-fold: (1) to determine whether there is a relationship between age and the proportion of light verbs produce during a narrative discourse task; and (2) to determine whether people with DAT produce a different proportion of light verbs compared with neurotypical adults.

METHODS & PROCEDURES

A total of 469 neurotypical adults and 12 participants with DAT produced narratives from a wordless picture book.

OUTCOME & RESULTS

The results indicated that light verb production increases as a function of age, even when controlling for education, and people with DAT produced a higher light verb-word ratio compared with neurotypical adults when matched for age and education.

CONCLUSION & IMPLICATION

Light verb use may increase as a function of age due to declines in retrieval ability. These declines are not only more pronounced in people with DAT, but also semantic knowledge deficits may contribute to a reliance on light verbs.

WHAT THIS PAPER ADDS

Light verbs are typically some of the first verbs learned due to their simple semantic construction and high frequency. However, two things are unknown: (1) how light verbs changed across the adult lifespan; and (2) whether cognitive impairment changes light verb production. The study found that light verb production increases as a function of age, and that people with DAT used a higher ratio of light verbs to words in a narrative task compared with neurotypical adults. However, despite the findings, more research is needed to determine their clinical utility. Future research may wish to investigate whether light verbs (1) facilitate comprehension in older adults or (2) may be used in cognitive-linguistic assessments for cognitive impairments.

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.

How Do Clinicians Judge Fluency in Aphasia?

PURPOSE

Aphasia fluency is multiply determined by underlying impairments in lexical retrieval, grammatical formulation, and speech production. This poses challenges for establishing a reliable and feasible tool to measure fluency in the clinic. We examine the reliability and validity of perceptual ratings and clinical perspectives on the utility and relevance of methods used to assess fluency.

METHOD

In an online survey, 112 speech-language pathologists rated spontaneous speech samples from 181 people with aphasia (PwA) on eight perceptual rating scales (overall fluency, speech rate, pausing, effort, melody, phrase length, grammaticality, and lexical retrieval) and answered questions about their current practices for assessing fluency in the clinic.

RESULTS

Interrater reliability for the eight perceptual rating scales ranged from fair to good. The most reliable scales were speech rate, pausing, and phrase length. Similarly, clinicians' perceived fluency ratings were most strongly correlated to objective measures of speech rate and utterance length but were also related to grammatical complexity, lexical diversity, and phonological errors. Clinicians' ratings reflected expected aphasia subtype patterns: Individuals with Broca's and transcortical motor aphasia were rated below average on fluency, whereas those with anomic, conduction, and Wernicke's aphasia were rated above average. Most respondents reported using multiple methods in the clinic to measure fluency but relying most frequently on subjective judgments.

CONCLUSIONS

This study lends support for the use of perceptual rating scales as valid assessments of speech-language production but highlights the need for a more reliable method for clinical use. We describe next steps for developing such a tool that is clinically feasible and helps to identify the underlying deficits disrupting fluency to inform treatment targets.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19326419.

Task-Specific Iconic Gesturing During Spoken Discourse in Aphasia

PURPOSE

In persons living with aphasia, we will explore the relationship between iconic gesture production during spontaneous speech and discourse task, spoken language, and demographic information.

METHOD

Employing the AphasiaBank database, we coded iconic gestures in 75 speakers with aphasia during two spoken discourse tasks: a procedural narrative, which involved participants telling the experimenter how to make a sandwich ("Sandwich"), and a picture sequence narrative, which had participants describe the picture sequence to the experimenter ("Window"). Forty-three produced a gesture during both tasks, and we further evaluate data from this subgroup as a more direct comparison between tasks.

RESULTS

More iconic gestures, at a higher rate, were produced during the procedural narrative. For both tasks, there was a relationship between iconic gesture rate, modeled as iconic gestures per word, and metrics of language dysfluency extracted from the discourse task as well as a metric of fluency extracted from a standardized battery. Iconic gesture production was correlated with aphasia duration, which was driven by performance during only a single task (Window), but not with other demographic metrics, such as aphasia severity or age. We also provide preliminary evidence for task differences shown through the lens of two types of iconic gestures.

CONCLUSIONS

While speech-language pathologists have utilized gesture in therapy for poststroke aphasia, due to its possible facilitatory role in spoken language, there has been considerably less work in understanding how gesture differs across naturalistic tasks and how we can best utilize this information to better assess gesture in aphasia and improve multimodal treatment for aphasia. Furthermore, our results contribute to gesture theory, particularly, about the role of gesture across naturalistic tasks and its relationship with spoken language. Supplemental Material https://doi.org/10.23641/asha.14614941.

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.

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.

Vocabulary Size Influences Spontaneous Speech in Native Language Users: Validating the Use of Automatic Speech Recognition in Individual Differences Research

Previous research has shown that vocabulary size affects performance on laboratory word production tasks. Individuals who know many words show faster lexical access and retrieve more words belonging to pre-specified categories than individuals who know fewer words. The present study examined the relationship between receptive vocabulary size and speaking skills as assessed in a natural sentence production task. We asked whether measures derived from spontaneous responses to everyday questions correlate with the size of participants' vocabulary. Moreover, we assessed the suitability of automatic speech recognition (ASR) for the analysis of participants' responses in complex language production data. We found that vocabulary size predicted indices of spontaneous speech: individuals with a larger vocabulary produced more words and had a higher speech-silence ratio compared to individuals with a smaller vocabulary. Importantly, these relationships were reliably identified using manual and automated transcription methods. Taken together, our results suggest that spontaneous speech elicitation is a useful method to investigate natural language production and that automatic speech recognition can alleviate the burden of labor-intensive speech transcription.

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.

Development of a measure of function word use in narrative discourse: core lexicon analysis in aphasia

BACKGROUND

Although discourse-level assessments contribute to predicting real-world performance in persons with aphasia (PWA), the use of discourse measures is uncommon in clinical settings due to resource-heavy procedures. Moreover, assessing function word use in discourse requires the arduous procedure of defining grammatical categories for each word in language transcripts.

AIMS

The purpose of this exploratory study was twofold: (1) to develop core function word lists as a clinician-friendly means of evaluating function word use in discourse; and (2) to examine the ability of the core function word measure to differentiate PWA from cognitively healthy adults and persons with fluent aphasia from non-fluent aphasia.

METHODS & PROCEDURES

The 25 most commonly used function words (core function words) were extracted from narrative language samples from 470 cognitively healthy adults, which were divided into seven age groups (20s, 30s, 40s, 50s, 60s, 70s and 80s). The percent agreement of core function words for 11 PWA (fluent aphasia = 5; non-fluent aphasia = 6) and 11 age- and education-matched controls were then calculated. Percent agreement for the core function words produced was compared between the controls and the PWA group, and between participants with fluent aphasia and non-fluent aphasia.

OUTCOMES & RESULTS

The results indicated that PWA produced fewer core function words from the lists than the control group, and that core function word use was strongly correlated with aphasia severity. Persons with non-fluent aphasia produced fewer core function words than those with fluent aphasia, although this could be a confound of aphasia classification from the use of the Western Aphasia Battery (WAB)-Revised.

CONCLUSIONS & IMPLICATIONS

Core function word lists consisting of a limited number of items for quantifying function word use in discourse remain in a nascent stage of development. However, the findings are consistent with previous studies analysing the total production of function words in language samples produced by PWA. Therefore, core function words may potentially serve as a clinician-friendly manner of quantifying function words produced in discourse. What this paper adds What is already known on the subject Function word analysis in discourse requires arduous processes of identifying the error production and grammatical category of function words in discourse. Previous studies have demonstrated that core lexicon measures are an efficient, simple means of quantifying discourse in PWA. However, function words have never been considered for generating an independent core lexicon list. What this paper adds to existing knowledge As an exploratory study, we focused primarily on developing a clinician-friendly measure to evaluate function word production in discourse, motivated by the idea of an adaptation strategy within the core lexicon framework. Our findings demonstrated that by using a simple scoring system that the core lexicon measure provides, we differentiated the control group from the PWA group, and persons with fluent aphasia from persons with non-fluent aphasia. Additionally, we found significant correlations between function word production and aphasia severity determined by WAB Aphasia Quotient (AQ). What are the potential or actual clinical implications of this work? The results add empirical evidence for the utility of core function word lists for quantifying function word usage in discourse in PWA. Counting the presence and absence of function words in discourse will allow clinicians to avoid labour-intensive preparatory work, and to obtain useful diagnostic information in a less time-consuming way.

Macrostructural Analyses of Cinderella Narratives in a Large Nonclinical Sample

Purpose Macrostructural narrative analyses are important clinical measures, revealing age-related declines and disorder-related impairments in the accuracy, completeness, logical sequencing, and organization of content. The current study aims to provide preliminary data on typical aging and psychometric evidence supporting multilevel Main Concept, Sequencing, and Story Grammar (MSSG) analyses that capture these aspects of narratives. Method Transcripts of Cinderella narratives for 92 healthy control participants stratified across four age brackets from the online database AphasiaBank were coded by Richardson and Dalton (2016) for main concept (MC) analysis. In the current study, MSSG analyses were completed for (a) logical sequencing, independently and in combination with MC accuracy and completeness (MC + sequencing), and (b) story grammar organization (i.e., inclusion of episodic components and complexity of episodes). Interrater agreement (99%-100%) revealed highly reliable scoring. Results Descriptive statistics for the typically aging sample are presented for sequencing, MC + sequencing, total episodic components, and episodic complexity. Scores for participants over 60 years of age were lower (poorer) than scores for those 20-59 years of age, supporting the construct validity of score use for identifying age-related declines in performance. Conclusions This study's novel MSSG analyses of narrative production efficiently assess the logical sequencing and story grammar organization of content in healthy controls. Preliminary reliability and validity evidence support the use of all scores to measure age-related changes in narrative macrostructure. Data from this typically aging sample provide a foundation for future research and clinical assessment aimed at quantifying narrative deficits in adults with communication disorders. Supplemental Material https://doi.org/10.23641/asha.12683495.

Concurrent Validity and Reliability of the Core Lexicon Measure as a Measure of Word Retrieval Ability in Aphasia Narratives

Purpose General agreement exists in the literature that clinicians struggle with quantifying discourse-level performance in clinical settings. Core lexicon analysis has gained recent attention as an alternative tool that may address difficulties that clinicians face. Although previous studies have demonstrated that core lexicon measures are an efficient means of assessing discourse in persons with aphasia (PWAs), the psychometric properties of core lexicon measures have yet to be investigated. The purpose of this study was (a) to examine the concurrent validity by using microlinguistic and macrolinguistic measures and (b) to demonstrate interrater reliability without transcription by raters with minimal training. Method Eleven language samples collected from PWAs were used in this study. Concurrent validity was assessed by correlating performance on the core lexicon measure with microlinguistic and macrolinguistic measures. For interrater reliability, 4 raters used the core lexicon checklists to score audio-recorded discourse samples from 10 PWAs. Results The core lexicon measures significantly correlated with microlinguistic and macrolinguistic measures. Acceptable interrater reliability was obtained among the 4 raters. Conclusions Core lexicon analysis is potentially useful for measuring word retrieval impairments at the discourse level. It may also be a feasible solution because it reduces the amount of preparatory work for discourse assessment.

Investigating Gray and White Matter Structural Substrates of Sex Differences in the Narrative Abilities of Healthy Adults

Linguistic aspects of narration have been investigated in healthy populations, in a wide variety of languages and speech genres with very different results. There is some evidence indicating that linguistic elements, such as speech rate (i.e., the measure indicating the amount of speech produced in a certain time period), mean length of utterance (MLU) (i.e., the index reflecting sentence grammatical structure), frequency of nouns and verbs, might be affected by non-linguistic factors such as sex. On the other hand, despite the existence of neuroimaging evidence of structural differences between males and females, it is yet unknown how such differences could explain between-sex disparities in linguistic abilities in natural speech contexts. To date, no study has evaluated discourse production elements in relation to sex differences and their neural correlates in terms of brain structure, a topic that could provide unique insights on the relationship between language and the brain. The aim of the present study was to determine sex differences in narrative skills in healthy adults and to investigate white and gray matter structural correlates of linguistic skills in each group. Twenty-seven male and 30 female (N = 57) right-handed, neurologically intact, monolingual Greek speakers, matched for age and years of education, participated. Narrations of a personal medical event were elicited. Linguistic elements of speech rate (words per minute), MLUs, frequency of nouns and verbs were calculated for each speech sample, by two independent raters. Structural 3D T1 images were segmented and parcellated using FreeSurfer and whole-brain between-sex differences in cortical thickness, cortical volume and surface area, were obtained. Between-group differences in white matter diffusion tensor scalars were examined via Tract-Based Spatial-Statistics and whole-brain tractography and automated tract delineation using Automated Fiber Quantification. Speech rate and noun frequency were significantly lower for men, while verb frequency was significantly higher for women, but no differences were identified for MLU. Regarding cortical measures, males demonstrated increased volume, surface area and cortical thickness in several bilateral regions, while no voxel-wise or tractography-based between-group differences in white matter metrics were observed. Regarding the relationship between sex and speech variables, hierarchical regression analyses showed that the superior/middle frontal cluster in surface area may serve as a significant predictor of speech rate variance, but only in females. We discuss several possible interpretations of how sex-related speech abilities could be represented differently in men and women in gray matter structures within the broad language network.

A Comparison of Three Discourse Elicitation Methods in Aphasia and Age-Matched Adults: Implications for Language Assessment and Outcome

Purpose Discourse analysis is commonly used to assess language ability and to evaluate language change following intervention in aphasia. The purpose of this study was to identify differences in language produced during different discourse tasks in a large aphasia group and an age- and education-matched control group. Method Four structured discourse tasks across 3 discourse types (expositional, narrative, and procedural) were evaluated in a group of adults with aphasia (n = 90) and an age-matched control group (n = 84) drawn from AphasiaBank. CLAN software was used to extract primary linguistic variables (mean length of utterance, propositional density, type-token ratio, words per minute, open-closed class word ratio, noun-verb ratio, and tokens), which served as proxies for various language abilities. Using a series of repeated-measures analyses of covariance, with significantly correlated demographic and descriptive variables as covariates, main effects of discourse type were evaluated. Results Despite an impoverished output from the aphasia group (i.e., the control group produced significantly more overall output), there was a main effect of discourse type on most primary linguistic variables in both groups, suggesting that, in adults with and without language impairments, each discourse type taxed components of the spoken language system to varying extents. Post hoc tests fleshed out these results, demonstrating that, for example, narrative discourse produced speech highest in propositional density. Conclusion Each discourse type taxes the language system in different ways, verifying the importance of using several discourse tasks and selecting the most sensitive discourse tasks when evaluating specific language abilities and outcomes.

Measuring word retrieval in narrative discourse: core lexicon in aphasia

BACKGROUND

Discourse analysis procedures are time consuming and impractical in a clinical setting. Critical to clinicians are simple and informative discourse measures that require minimal time and labour to complete. Many studies, however, have overlooked difficulties that clinicians face. We recently developed core lexicon lists for nouns, verbs, adjectives and adverbs for two narrative discourse tasks with healthy control groups. Core lexicon lists consist of important lexical items required to produce coherently meaningful discourse in response to discourse tasks. Measuring core lexicon is useful for quantifying word retrieval impairments at the discourse level in clinical populations.

AIMS

To apply an age-based core lexicon list for nouns, verbs, adjectives and adverbs for the wordless picture books Good Dog Carl (1985) and Picnic (1984) and to determine how well the lists measured linguistic impairments in persons with aphasia (PWA).

MATERIALS & METHODS

Lemma forms were extracted from 470 control participants who were divided into seven age groups. Twenty-five core lexicons were identified for four word classes (nouns, verbs, adjectives and adverbs) among the seven age groups. The nouns, verbs, adjectives and adverbs for each PWA (N = 11) were then compared with the core lexicon for their respective age group. Per cent agreement was computed by comparing the number of total items within each list to the number of items that PWA produced. A Spearman's correlation coefficient was computed between the WAB-R AQ and the per cent agreement for each word type for PWA.

OUTCOMES & RESULTS

The percentage of agreement for each word type among the age cohorts ranged between 56% and 96%. Of the four word types, core verbs significantly correlated with the WAB AQs for both discourse tasks. A post-hoc analysis found significant differences between fluent and non-fluent aphasia for core verbs.

CONCLUSIONS & IMPLICATIONS

Core lexicon analysis appears to be a practical way to capture impairments in word retrieval at the discourse level. Core verbs may be a better indicator to understand holistic language performances for PWA. Use of the core lexicon checklist can serve as an option to reconcile ecological validity with clinical usability.

Measuring discourse coherence in anomic aphasia using Rhetorical Structure Theory

PURPOSE

The existing body of work regarding discourse coherence in aphasia has provided mixed results, leaving the question of coherence being impaired or intact as a result of brain injury unanswered. In this study, discourse coherence in non-brain-damaged (NBD) speakers and speakers with anomic aphasia was investigated quantitatively and qualitatively.

METHOD

Fifteen native speakers of Cantonese with anomic aphasia and 15 NBD participants produced 60 language samples. Elicitation tasks included story-telling induced by a picture series and a procedural description. The samples were annotated for discourse structure in the framework of Rhetorical Structure Theory (RST) in order to analyse a number of structural parameters. After that 20 naïve listeners rated coherence of each sample.

RESULT

Disordered discourse was rated as significantly less coherent. The NBD group demonstrated a higher production fluency than the participants with aphasia and used a richer set of semantic relations to create discourse, particularly in the description of settings, expression of causality, and extent of elaboration. People with aphasia also tended to omit essential information content.

CONCLUSION

Reduced essential information content, lower degree of elaboration, and a larger amount of structural disruptions may have contributed to the reduced overall discourse coherence in speakers with anomic aphasia.

Oral and written picture description in individuals with aphasia

BACKGROUND

Aphasia is characterized by difficulties in connected speech/writing.

AIMS

To explore the differences between the oral and written description of a picture in individuals with chronic aphasia (IWA) and healthy controls. Descriptions were controlled for productivity, efficiency, grammatical organization, substitution behaviour and discourse organization.

METHODS & PROCEDURES

Fifty IWA and 50 healthy controls matched for age, gender and education provided an oral and written description of a black-and-white situational drawing from the Dutch version of the Comprehensive Aphasia Test. Between- and within-group analyses were carried out and the reliability of the test instrument was assessed.

OUTCOMES & RESULTS

The language samples of the healthy controls were more elaborate, more efficient, syntactically richer, more coherent, and consisted of fewer spoken and written language errors than the samples of the IWA. Within-group comparisons showed that connected writing is more sensitive than connected speech to capture aphasic symptoms.

CONCLUSIONS & IMPLICATIONS

The analysis of both modalities (speech and writing) at the discourse level allows one to assess simultaneously micro- and macro-linguistic skills and their potential interrelations in a given IWA. Connected writing appears to be more sensitive in discriminating IWA from healthy controls than connected speech. This method for analyzing language samples should, however, be used in conjunction with other assessment tools.

Manual Versus Automated Narrative Analysis of Agrammatic Production Patterns: The Northwestern Narrative Language Analysis and Computerized Language Analysis

PURPOSE

The purpose of this study is to compare the outcomes of the manually coded Northwestern Narrative Language Analysis (NNLA) system, which was developed for characterizing agrammatic production patterns, and the automated Computerized Language Analysis (CLAN) system, which has recently been adopted to analyze speech samples of individuals with aphasia (a) for reliability purposes to ascertain whether they yield similar results and (b) to evaluate CLAN for its ability to automatically identify language variables important for detailing agrammatic production patterns.

METHOD

The same set of Cinderella narrative samples from 8 participants with a clinical diagnosis of agrammatic aphasia and 10 cognitively healthy control participants were transcribed and coded using NNLA and CLAN. Both coding systems were utilized to quantify and characterize speech production patterns across several microsyntactic levels: utterance, sentence, lexical, morphological, and verb argument structure levels. Agreement between the 2 coding systems was computed for variables coded by both.

RESULTS

Comparison of the 2 systems revealed high agreement for most, but not all, lexical-level and morphological-level variables. However, NNLA elucidated utterance-level, sentence-level, and verb argument structure-level impairments, important for assessment and treatment of agrammatism, which are not automatically coded by CLAN.

CONCLUSIONS

CLAN automatically and reliably codes most lexical and morphological variables but does not automatically quantify variables important for detailing production deficits in agrammatic aphasia, although conventions for manually coding some of these variables in Codes for the Human Analysis of Transcripts are possible. Suggestions for combining automated programs and manual coding to capture these variables or revising CLAN to automate coding of these variables are discussed.

Connected Language in Late Middle-Aged Adults at Risk for Alzheimer's Disease

Connected language is often impaired among people with Alzheimer's disease (AD), yet little is known about when language difficulties first emerge on the path to a clinical diagnosis. The objective of this study was to determine whether individuals with psychometric (preclinical) evidence of amnestic mild cognitive impairment (pMCI) showed deficits in connected language measures. Participants were 39 pMCI and 39 cognitively healthy (CH) adults drawn from the Wisconsin Registry for Alzheimer's Prevention, who were matched for age, literacy, and sex. Participants completed a connected language task in which they described the Cookie Theft picture from the Boston Diagnostic Aphasia Examination. Language samples were analyzed across three language domains: content, syntactic complexity, and speech fluency. Paired t-tests were used to compare CH and pMCI groups on all variables, and Cohen's d effect sizes were calculated for each comparison. The CH and pMCI groups differed significantly on measures of content (e.g., CH group produced more semantic units, more unique words and had larger idea density, on average, than the pMCI group). The picture description findings are consistent with previous retrospective studies showing semantic language differences in adults with autopsy-confirmed AD. Given that these comparisons are between cognitively healthy and pMCI individuals (before a clinical MCI diagnosis), these findings may represent subtle language difficulty in spontaneous speech, and may be predictive of larger language changes over time.

The effect of cortical and subcortical lesions on spontaneous expression of memory-encoded and emotionally infused information: Evidence for a role of the ventral stream

The ventral stream of language processing has been implicated in the spontaneous expression of memory-encoded and emotionally infused information. The present study investigated whether left hemispheric lesions in post-stroke right-handed aphasic patients may be selectively associated with specific language functions. Speech rate was assessed with two tasks, one based on autobiographical memory of an emotionally infused event (stroke story narration) and the other based on information that is visually available at the time of speech generation ("cookie theft" picture description). CT and/or MRI scans were obtained for each patient and lesions located in 16 regions of the left hemisphere were identified and coded. The total number of cortical and subcortical areas affected served as a measure of lesion extent. While mean speech rates were similar across conditions, there were different patterns of association between each index and specific lesion sites. Non-parametric quantile regression statistical models constructed to assess dependence of both speech rate indices on each lesion locus indicated that the speech rate in the stroke story had significant inverse associations with total number of lesioned areas, as well as lesions in the inferior frontal gyrus and the external/extreme capsule region. The cookie theft speech rate had significant inverse associations with total number of lesioned areas as well as lesion in the inferior frontal gyrus, but not with the external/extreme capsule region. In sum, integrity of the extreme/external capsule region appears to be important selectively for the Stroke Story task, supporting the hypothesis that the ventral stream plays a central role in spontaneous expression of memory-encoded and emotionally infused information.

Semantic Knowledge Use in Discourse: Influence of Age

Semantic memory is relatively stable across the lifespan (Rönnlund, Nyberg, & Bäckman, 2005; Spaniol, Madden, & Voss, 2006); however, most research has been conducted at the single concept level. Few researchers have examined how semantic knowledge is used in discourse. The purpose of the study, then, was to determine the proportion of semantic knowledge and category domains used in discourse produced by younger and older participants. Cognitively healthy, younger (n=30, 20-39) and older (n=30; 60-89) participants told stories that were transcribed and coded for 10 domains of semantic knowledge and also living and nonliving things. Results indicated group differences for the proportion of semantic knowledge type, sound, and for the category type, living things. These findings extend previous research on semantic features into the realm of discourse and indicate the importance of studying semantic features and categories within discourse.

Do age-related word retrieval difficulties appear (or disappear) in connected speech?

We conducted a comprehensive literature review of studies of word retrieval in connected speech in healthy aging and reviewed relevant aphasia research that could shed light on the aging literature. Four main hypotheses guided the review: (1) Significant retrieval difficulties would lead to reduced output in connected speech. (2) Significant retrieval difficulties would lead to a more limited lexical variety in connected speech. (3) Significant retrieval difficulties would lead to an increase in word substitution errors and in pronoun use as well as to greater dysfluency and hesitation in connected speech. (4) Retrieval difficulties on tests of single-word production would be associated with measures of word retrieval in connected speech. Studies on aging did not confirm these four hypotheses, unlike studies on aphasia that generally did. The review suggests that future research should investigate how context facilitates word production in old age.

Microlinguistic processes that contribute to the ability to relay main events: influence of age

The purpose of the current study was to determine the microlinguistic processes that contribute to picture description in healthy adults across the life span. Two-hundred forty healthy adults were separated into three groups, young (n = 80; 20-39), middle (n = 80; 40-69), and older (n = 80; 70-89). Participants provided language samples in response to two single and two sequential pictures analyzed for total number of words, informativeness, lexical diversity, syntactic complexity, and main events. The older group produced a significantly lower proportion of main events for the single and sequential pictures compared to the other groups. Group differences on the microlinguistic measures varied depending on the measure and the stimulus type. Further, regardless of task, total number of words significantly related to main event production for the young and middle aged groups, but not the older group. Results of the current study extend previous findings by researchers who have investigated discourse production in cognitively healthy, older adults. Using a multi-level approach, we found that linguistic processes across different levels interact; however, the relationship is age-dependent. By including a middle-aged group we identify the potential course of documented change and our results indicate that the changes in language processes with age may not be linear.

Core-Lexicon and Main-Concept Production During Picture-Sequence Description in Adults Without Brain Damage and Adults With Aphasia

PURPOSE

We sought to identify the core lexicon of a picture-description task using transcripts from the AphasiaBank database and to determine differences in core-lexicon usage between control speakers and persons with aphasia (PWAs). We also investigated the relationship between core lexicon and an established discourse measure, main-concept analysis.

METHOD

A core lexicon was developed by identifying lemmas produced by 92 control speakers. Transcripts were scored-165 control transcripts and 238 PWA transcripts-using the core lexicon and a recently developed main-concept list. Median tests examined differences between controls, PWAs, and aphasia subtypes. Spearman's correlations assessed the relationship between core-lexicon and main-concept performance.

RESULTS

A 24-item core lexicon was identified. Significant differences were found between control speakers and PWAs, and between aphasia subtypes, for core-lexicon and main-concept scores. Core-lexicon and main-concept performance was significantly and positively correlated for all groups.

CONCLUSIONS

We report the development of a core lexicon, differences in core-lexicon usage between speakers, and the relationship between core-lexicon and main-concept scores. Research is needed to determine the clinical utility and psychometric properties of these discourse measures and their potential contribution to multilevel discourse analysis of functional communication.

Evaluating measures of global coherence ability in stories in adults

BACKGROUND

Discourse coherence is a reflection of the listener's ability to interpret the overall meaning conveyed by the speaker. Measuring global coherence (maintenance of thematic unity of the discourse) is useful for quantifying communication impairments at the discourse level in clinical populations and for measuring response to discourse-level treatments.

AIMS

The aim was to determine feasibility of a four-point global coherence scale developed by the authors. Specifically, they were (1) to estimate measurement reliability of the four-point global coherence scale; and (2) to estimate construct validity for the four-point global coherence scale.

METHOD & PROCEDURES

Fifty cognitively healthy adults aged between 28 and 58 years participated in the study. Participants viewed and then told the stories depicted in two wordless picture books. Participants' stories were orthographically transcribed and segmented into communication units (C-unit). Raters scored each participant's story for global coherence using two global coherence scales (four- and five-point scales). Each C-unit received an individual score, then the mean global coherence score was computed, resulting in two mean global coherence scores for each coherence scale, one for each story, for all participants.

OUTCOMES & RESULTS

Results indicated high reliability estimates for the scale. In addition, construct validity, specifically face validity and convergent validity, was effectively estimated for using the four-point scale as a measure of maintenance of global coherence in stories told by cognitively healthy adults. Lastly, it was found that the wordless picture books elicited stories that are comparable and can be reliably interchanged as different forms to evaluate maintenance of global coherence.

CONCLUSIONS & IMPLICATIONS

The assumptions that the measure is feasible were achieved and face and convergent validity were adequately estimated. Future investigations should consider estimating predictive validity, concurrent validity and discriminant validity of the measure.

Considering a multi-level approach to understanding maintenance of global coherence in adults with aphasia

BACKGROUND: Discourse is a naturally occurring, dynamic form of communication. Coherence is one aspect of discourse and is a reflection of the listener's ability to interpret the overall meaning conveyed by the speaker. Adults with aphasia may present with impaired maintenance of global coherence, which, in turn, may contribute to their difficulties in overall communicative competence. AIMS: The aim of the study was to determine if microlinguistic processes contribute to maintenance of global coherence in adults with and without aphasia. METHOD AND PROCEDURES: Participants included 15 adults with aphasia (PWA) and 15 healthy controls (HC). Study participants told stories conveyed in wordless picture books. The discourse samples were transcribed and then analyzed for percent of information units produced, lexical diversity, syntactic complexity, and maintenance of global coherence. OUTCOMES AND RESULTS: Several linear regression models were carried out to investigate the relationship among the microlinguistic and macrolinguistic measures. For the control group, percent of information units conveyed was a significant predictor of maintenance of global coherence for stories told. For the aphasia group, percent of information units conveyed and lexical diversity were significant predictors of maintenance of global coherence for stories told. CONCLUSIONS: Results indicated that microlinguistic processes contribute to the maintenance of global coherence in stories told by adults with aphasia. These findings have important clinical implications for using a multi-level discourse model for analyzing discourse ability in adults with aphasia and measuring individual response to treatment.

AphasiaBank: Methods for Studying Discourse

BACKGROUND: AphasiaBank is a computerized database of interviews between persons with aphasia (PWAs) and clinicians. By February 2011, the database had grown to include 145 PWAs and 126 controls from 12 sites across the United States. The data and related analysis programs are available free over the web. AIMS: The overall goal of AphasiaBank is the construction of a system for accumulating and sharing data on language usage by PWAs. To achieve this goal, we have developed a standard elicitation protocol and systematic automatic and manual methods for transcription, coding, and analysis. METHODS #ENTITYSTARTX00026; PROCEDURES: We present sample analyses of transcripts from the retelling of the Cinderella story. These analyses illustrate the application of our methods for the study of phonological, lexical, semantic, morphological, syntactic, temporal, prosodic, gestural, and discourse features. MAIN CONTRIBUTION: AphasiaBank will allow researchers access to a large, shared database that can facilitate hypothesis testing and increase methodological replicability, precision, and transparency. CONCLUSIONS: AphasiaBank will provide researchers with an important new tool in the study of aphasia.

Lexical diversity for adults with and without aphasia across discourse elicitation tasks

BACKGROUND: Differences in lexical diversity (LD) across different discourse elicitation tasks have been found in neurologically intact adults (NIA) (Fergadiotis, Wright, & Capilouto, 2010) but have not been investigated systematically in people with aphasia (PWA). Measuring lexical diversity in PWA may serve as a useful clinical tool for evaluating the impact of word retrieval difficulties at the discourse level. AIMS: The study aims were (a) to explore the differences between the oral language samples of PWA and NIA in terms of LD as measured by dedicated computer software (voc-D), (b) to determine whether PWA are sensitive to discourse elicitation task in terms of LD, and (c) to identify whether differences between PWA and NIA vary in magnitude as a function of discourse task. METHOD #ENTITYSTARTX00026; PROCEDURES: Oral language samples from 25 PWA and 27 NIA were analysed. Participants completed three commonly used discourse elicitation tasks (single pictures, sequential pictures, story telling) and voc-D was used to obtain estimates of their LD. OUTCOMES #ENTITYSTARTX00026; RESULTS: A mixed 2 × 3 ANOVA revealed a significant group task interaction that was followed by an investigation of simple main effects and tetrad×comparisons. Different patterns of LD were uncovered for each group. For the NIA group results were consistent with previous findings in the literature according to which LD varies as a function of elicitation technique. However, for PWA sequential pictures and story telling elicited comparable estimates of LD. CONCLUSIONS: Results indicated that LD is one of the microlinguistic indices that are influenced by elicitation task and the presence of aphasia. These findings have important implications for modelling lexical diversity and selecting and interpreting results from different discourse elicitation tasks.