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

Discourse- and lesion-based aphasia quotient estimation using machine learning

Discourse is a fundamentally important aspect of communication, and discourse production provides a wealth of information about linguistic ability. Aphasia commonly affects, in multiple ways, the ability to produce discourse. Comprehensive aphasia assessments such as the Western Aphasia Battery-Revised (WAB-R) are time- and resource-intensive. We examined whether discourse measures can be used to estimate WAB-R Aphasia Quotient (AQ), and whether this can serve as an ecologically valid, less resource-intensive measure. We used features extracted from discourse tasks using three AphasiaBank prompts involving expositional (picture description), story narrative, and procedural discourse. These features were used to train a machine learning model to predict the WAB-R AQ. We also compared and supplemented the model with lesion location information from structural neuroimaging. We found that discourse-based models could estimate AQ well, and that they outperformed models based on lesion features. Addition of lesion features to the discourse features did not improve the performance of the discourse model substantially. Inspection of the most informative discourse features revealed that different prompt types taxed different aspects of language. These findings suggest that discourse can be used to estimate aphasia severity, and provide insight into the linguistic content elicited by different types of discourse prompts.

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.

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.

Reactivity of the triple task on writing processes and product in adults with dyslexia

Introduction

The triple task (TT) is a method for assessing the dynamics of writing processes. It involves three tasks in one: writing a text, responding to a sound, and reporting the process. Previous research has mostly shown that the TT does not affect the writing process or the product. However, individuals with dyslexia often show difficulties in tasks that require organization, automation, integration of multiple processes, inhibition, and shifting/cognitive flexibility. The aim of this study was therefore to investigate whether TT affects the writing process and written product differently in adults with dyslexia compared to a control group of adults with typical reading skills.

Methods

Two groups of adult native Croatian speakers were included in this study: 20 adults with developmental dyslexia and 20 adults with typical reading skills; evenly distributed by: age (18-38 years), gender (13 males, 7 females per group), educational level, and nonverbal cognitive abilities. All participants wrote one text with a TT and another without. The writing of the text was tracked with a keystroke logging program - Inputlog. The two texts were compared at process and product level.

Results and discussion

The results showed that measures of writing processes and text quality in the groups of adults with dyslexia and adults with typical reading skills were unlikely to be differentially affected by TT. However, in the condition without TT, the total number of characters per minute was higher, more keys were typed per minute and more words were deleted. As expected, adults with dyslexia produced shorter texts of lower quality and with more errors; they also produced fewer characters per minute, used fewer keystrokes and typed fewer.

Conclusion

The study suggests that TT is unlikely to have a different impact on the writing process or written product in adults with dyslexia compared to adults with typical reading skills.

Analyzing Language in the Picnic Scene Picture and in Conversation: The Type of Discourse Sample We Choose Influences Findings in People With Aphasia

PURPOSE

People with aphasia express that improved conversational discourse is a primary rehabilitation goal. Discourse is usually assessed using monologue, such as a picture description task, but research shows that language in monologue varies from language in everyday conversation. Consequently, we investigated the relationship of language in unstructured conversation and in the picnic scene picture because it is a part of the most often used aphasia battery (Western Aphasia Battery-Revised) and thus is frequently used to inform therapy. Second, because previous research suggests people with severe aphasia may not demonstrate language production variability between types of monologue-level discourse, we evaluated the relationship of severity and the difference in scores between conversation and the picnic scene task.

METHOD

Thirty-four people with mild-to-severe aphasia described the picnic scene and provided a conversation sample. We measured language production and communicative success using seven measures with established psychometrics in conversation/monologue. We conducted correlations to answer the research questions.

RESULTS

Correlations were moderate and weaker for the measures in the two conditions. A strong negative relationship was demonstrated between aphasia severity and global coherence. All other relationships were moderate and weaker for the remaining measures when correlated with aphasia severity (also negative).

CONCLUSIONS

Results are consistent with other studies indicating that language varies in different types of discourse. We conclude that for accurate, meaningful assessment, discourse sampling needs to include the specific type of discourse the individual wishes to address in therapy, because discourse samples and their findings are not interchangeable.

Clinical Guidelines for Eliciting Discourse Using the RHDBank Protocol

PURPOSE

Examining discourse after right hemisphere brain damage (RHD) can provide invaluable clinical data and insight into functional communication capabilities. Yet, clinicians preparing to enter the field may have limited experience eliciting and analyzing discourse for therapeutic purposes. The purpose of this work is to present a practical guide for the clinical use of the RHDBank protocol.

METHOD

Following a brief overview of the RHDBank protocol, elicitation guidelines and protocol administration considerations are offered. Measures that should be considered when analyzing RHDBank-elicited discourse are summarized. The RHDBank protocol is positioned as an accessible resource for discourse elicitation in the clinical setting, and examples for the clinical use of the protocol are provided.

CONCLUSIONS

Discourse production can be a key source of information regarding communication ability following RHD. The RHDBank provides a structured and scripted approach to the clinical elicitation of language and consideration of discourse production. Its immediate clinical utility will assist developing clinicians with the acquisition of a clinically relevant elicitation approach and more comprehensive view of the RHD communication impairments. Application of the protocol can aid in collective knowledge advancement that will promote a better understanding of RHD language production as a clinical entity with an array of possible characteristics.

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.

Adaptation and validation of the main concept analysis of spoken discourse by native Japanese adults

Many people with aphasia demonstrate problems of oral production at the discourse level. The Main Concept Analysis (MCA) for oral discourse production is a published evidence-based battery for quantifying the degree of presence, accuracy, completeness, and efficiency of targeted main concepts in oral discourse. In Japan, such a standardized tool specialized for assessing spoken discourse is currently lacking. The purpose of this study was to adapt the Japanese version of MCA for oral discourse production (the Japanese-MCA) and examine its validity and reliability. Stage 1 of the study involved the establishment of linguistically-specific main concepts (MCs) of the Japanese-MCA. Ten speech-language-hearing therapists and 60 healthy participants who were native monolingual Japanese speakers were recruited to determine MCs. Stage 2 examined the criterion validity and reliability of the Japanese-MCA. Language samples of 20 participants with aphasia, as verified by Standard Language Test of Aphasia (SLTA), and 20 healthy older participants were used. Results of Stage 1 of the study yielded normative data with a set of target MCs that were geographically and linguistically specific for use in Japan. The results also revealed the comparability of the Japanese-MCA and previously reported versions of other languages. Stage 2 findings indicated not only a high correlation of criterion validity, but also good reliability of the test. With established norms and specific scoring criteria of the Japanese-MCA, it is believed that this new tool will become a useful addition to clinical management and research of aphasia in Japan.

Assessment of language impairment and function

This chapter is written for the qualified neurologist or related professional working with persons who have had a stroke or other sudden brain injury. It is critical that the presence of aphasia is detected, no matter how mild the presentation, and to support that assertion, this chapter highlights the plight of persons with latent aphasia. At the individual level, the impact of aphasia is devastating, with overwhelming evidence that aphasia negatively impacts psychosocial outcomes. At the global level, sensitive detection and accurate diagnosis of aphasia are critical for accurate characterization and quantification of the global burden of aphasia. The word "LANGUAGE" is leveraged as an acronym to create a useful and memorable checklist to guide navigation of aphasia screening and assessment: it begins with the definition of language (L), followed by the definition and diagnostic criteria for aphasia (A). Then language abilities and characteristics to be considered in assessment are presented: naming (N); grammar and syntax (G); unintelligible words, jargon, and paraphasias (U); auditory comprehension and repetition (A); graphemic abilities-reading and writing (G); and everyday communication and discourse (E). Recommendations for improving procedural adherence are provided, and a list of potential brief assessment measures are introduced.

Predicting Severity in People with Aphasia: A Natural Language Processing and Machine Learning Approach

Speech language pathologists need an accurate assessment of the severity of people with aphasia (PWA) to design and provide the best course of therapy. Currently, severity is evaluated manually by an increasingly scarce pool of experienced and well-trained clinicians, taking considerable time resources. By analyzing the transcripts from three discourse elicitation methods, this study combines natural language processing (NLP) and machine learning (ML) to predict the severity of PWA, both by score and severity level. By engineering language features from PWA tasks, an unstructured k-means clustering presents distinct aphasia types, showing validity of the selected features. We develop regression models to predict severity scores along with a classification of severity by level (Mild, Moderate, Severe, and Very Severe) to assist clinicians to easily plan and monitor the course of treatment. Our best ML regression model uses a deep neural network and results in a mean absolute error (MAE) of 0.0671 and root mean squared error (RMSE) of 0.0922. Our best classification model uses a random forest and result in an overall accuracy of 73%, with the highest accuracy of 87.5% for mild severity. Our results suggest that using NLP and ML provides an accurate and cost-effective approach to evaluate the severity levels in PWA to consequently help clinicians determine rehabilitation procedures.

Enhancing the Classification of Aphasia: A Statistical Analysis Using Connected Speech

BACKGROUND

Large shared databases and automated language analyses allow for the application of new data analysis techniques that can shed new light on the connected speech of people with aphasia (PWA).

AIMS

To identify coherent clusters of PWA based on language output using unsupervised statistical algorithms and to identify features that are most strongly associated with those clusters.

METHODS & PROCEDURES

Clustering and classification methods were applied to language production data from 168 PWA. Language samples were from a standard discourse protocol tapping four genres: free speech personal narratives, picture descriptions, Cinderella storytelling, procedural discourse.

OUTCOMES & RESULTS

Seven distinct clusters of PWA were identified by the K-means algorithm. Using the random forests algorithm, a classification tree was proposed and validated, showing 91% agreement with the cluster assignments. This representative tree used only two variables to divide the data into distinct groups: total words from free speech tasks and total closed class words from the Cinderella storytelling task.

CONCLUSION

Connected speech data can be used to distinguish PWA into coherent groups, providing insight into traditional aphasia classifications, factors that may guide discourse research and clinical work.

Spectral Resting-State EEG (rsEEG) in Chronic Aphasia Is Reliable, Sensitive, and Correlates With Functional Behavior

We investigated spectral resting-state EEG in persons with chronic stroke-induced aphasia to determine its reliability, sensitivity, and relationship to functional behaviors. Resting-state EEG has not yet been characterized in this population and was selected given the demonstrated potential of resting-state investigations using other neuroimaging techniques to guide clinical decision-making. Controls and persons with chronic stroke-induced aphasia completed two EEG recording sessions, separated by approximately 1 month, as well as behavioral assessments of language, sensorimotor, and cognitive domains. Power in the classic frequency bands (delta, theta, alpha, and beta) was examined via spectral analysis of resting-state EEG data. Results suggest that power in the theta, alpha, and beta bands is reliable for use as a repeated measure. Significantly greater theta and lower beta power was observed in persons with aphasia (PWAs) than controls. Finally, in PWAs theta power negatively correlated with performance on a discourse informativeness measure, while alpha and beta power positively correlated with performance on the same measure. This indicates that spectral rsEEG slowing observed in PWAs in the chronic stage is pathological and suggests a possible avenue for directly altering brain activation to improve behavioral function. Taken together, these results suggest that spectral resting-state EEG holds promise for sensitive measurement of functioning and change in persons with chronic aphasia. Future studies investigating the utility of these measures as biomarkers of frank or latent aphasic deficits and treatment response in chronic stroke-induced aphasia are warranted.

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.

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.

Moving Toward Non-transcription based Discourse Analysis in Stable and Progressive Aphasia

Measurement of communication ability at the discourse level holds promise for predicting how well persons with stable (e.g., stroke-induced), or progressive aphasia navigate everyday communicative interactions. However, barriers to the clinical utilization of discourse measures have persisted. Recent advancements in the standardization of elicitation protocols and the existence of large databases for development of normative references have begun to address some of these barriers. Still, time remains a consistently reported barrier by clinicians. Non-transcription based discourse measurement would reduce the time required for discourse analysis, making clinical utilization a reality. The purpose of this article is to present evidence regarding discourse measures (main concept analysis, core lexicon, and derived efficiency scores) that are well suited to non-transcription based analysis. Combined with previous research, our results suggest that these measures are sensitive to changes following stroke or neurodegenerative disease. Given the evidence, further research specifically assessing the reliability of these measures in clinical implementation is warranted.