Reading for Meaning: The Influence of Reader Characteristics on Paragraph Understanding in Aphasia.

PURPOSE: The study improves our understanding of the reading comprehension difficulties seen in people with aphasia. It investigates the influence of reader characteristics, including personal demographic variables, and linguistic and wider cognitive skills, on text comprehension. METHOD: Seventy-five people with aphasia and 87 neurologically typical readers completed a test of paragraph comprehension. People with aphasia also completed background tests of language, attention, recognition memory, and executive functions. The influence of demographic variables (age, gender, and level of education) was analyzed separately in the group of people with aphasia and the typical readers using analyses of variance. In the people with aphasia, the relationship between paragraph comprehension and the language and cognitive tests was explored using correlational analyses. RESULTS: In the typical readers, there was a significant effect of gender and level of education and a significant three-way interaction. For the people with aphasia, there were no significant effects of demographic variables. Significant positive correlations were found between performance on paragraph comprehension and each of the language tests and with tests of auditory attention, executive functions, and recognition memory for words. CONCLUSIONS: In people with aphasia, the effects of demographic variables were overshadowed by the effect of their language difficulties. The association seen across language measures reflects the shared semantic representations across single-word, sentence, and text levels, across modalities. The study emphasizes the importance of attention, executive functions, and short-term memory in the comprehension of and memory for what we read. The contribution of both language difficulties and wider cognitive skills needs to be considered when planning intervention. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24695451.

Language-Specific Dual-Task Effects After Stroke: A Systematic Review.

PURPOSE: The dual-task paradigm has been frequently used to examine stroke-related deficits because it samples behavioral performance under conditions of distraction similar to functioning in real-life environments. This original systematic review synthesizes studies that examined dual-task effects involving spoken language production in adults affected by stroke, including transient ischemic attack (TIA) and poststroke aphasia. METHOD: Five databases were searched (inception to March 2022) for eligible peer-reviewed articles. The 21 included studies reported a total of 561 stroke participants. Thirteen studies focused on single word production, for example, word fluency, and eight on discourse production, for example, storytelling. Most studies included participants who had suffered a major stroke. Six studies focused on aphasia, whereas no study focused on TIA. A meta-analysis was not appropriate because of the heterogeneity of outcome measures. RESULTS: Some single word production studies found dual-task language effects whereas others did not. This finding was compounded by the lack of appropriate control participants. Most single word and discourse studies utilized motoric tasks in the dual-task condition. Our certainty (or confidence) assessment was based on a methodological appraisal of each study and information about reliability/fidelity. As 10 of the 21 studies included appropriate control groups and limited reliability/fidelity information, the certainty of the findings may be described as weak. CONCLUSIONS: Language-specific dual-task costs were identified in single word studies, especially those that focused on aphasia as well as half of the nonaphasia studies. Unlike single word studies, nearly all studies of discourse showed dual-task decrements on at least some variables. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23605311.

Semantic impairment in aphasia: A problem of control?

Purpose: The relationship between cognitive processes and language ability in aphasia has recently gained increasing attention, with some authors suggesting that control impairments may underlie difficulties with semantic tasks in aphasia. This paper aims to present an overview of the current research on the involvement of cognitive processes in semantic processing tasks and discuss the proposed relationship between cognitive control and semantic processing in aphasia.Method: The role of cognitive processes in semantic processing tasks commonly used in the aphasiology literature is discussed and two theoretical approaches to semantic processing that contribute to the understanding of the nature of semantic breakdown in aphasia are outlined. Finally, we examine the evidence put forward in the Controlled Semantic Cognition framework with regard to the interpretation of impaired performance on semantic processing tasks in people with aphasia.Result: Non-linguistic cognitive abilities such as working memory, inhibition and control are required by semantic processing tasks, in addition to access to conceptual information, making it difficult to dissociate these abilities. Several issues exist regarding the evidence put forward for a control deficit as the underlying cause of poor performance on semantic processing tasks in aphasia.Conclusion: It remains unclear whether impairment on semantic tasks in people with aphasia is related to problems with the representation and/or processing (activation/retrieval) of meaning or problems with cognitive control (or both). Further research is still needed to fully understand how non-linguistic cognitive processes interact with semantic processing, as well as clarify and consistency the definition of control.

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.

Reliability and validity of the Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39) for a Serbian population.

Purpose: Aphasia has a negative impact on a person's quality of life (QOL). The Stroke Aphasia Quality of Life-39 scale (SAQOL-39) is a widely-used measure of health-related quality of life (HRQOL) developed for people with aphasia that has been translated into several languages. Its psychometric properties have been examined not only in English, but also in other languages. This study examined the reliability and validity of a translation and adaptation of the SAQOL-39 into Serbian in Serbian-speaking people with aphasia.Method: Using forward and backward translation, the SAQOL-39 was translated and adapted from English into Serbian and its psychometric properties were examined in 90 Serbian-speaking people with a broad range of times post-onset of aphasia. Internal consistency, test-retest reliability and other analyses were conducted.Result: Internal consistency and test-retest reliability of the Serbian version was high (Cronbach's α > 0.9; ICC ≥0.87), which is similar to versions of the scale in other languages.Conclusion: The Serbian translation and adaptation of the SAQOL-39 was shown to be a valid and reliable measure of QOL in people with aphasia with reliable psychometric properties and is suitable for the assessment of Serbian people with aphasia.

Demystifying the Complexity of Aphasia Treatment: Application of the Rehabilitation Treatment Specification Systemx.

A considerable body of research supports the use of behavioral communication treatment as the standard of care for aphasia. In spite of robust progress in clinical aphasiology, many questions regarding optimal care remain unanswered. One of the major challenges to progress in the field is the lack of a common framework to adequately describe individual treatments, which, if available, would allow comparisons across studies as well as improved communication among researchers, clinicians, and other stakeholders. Here, we describe how aphasia treatment approaches can be systematically characterized using the Rehabilitation Treatment Specification System (RTSS). At the core of the RTSS is a tripartite structure that focuses on targets (the behavior that is expected to change as a result of treatment), ingredients (what a clinician does to affect change in the target), and mechanism(s) of action (why a given treatment works by linking the ingredients to the target). Three separate articles in the current issue specifically describe how the RTSS can be used to describe different kinds of aphasia treatment approaches: functional approaches, cognitive-linguistic approaches, and biological approaches. It is our hope that the application of the RTSS in clinical aphasiology will improve communication in published studies, grant proposals, and in the clinical care of persons with aphasia.

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

The Rehabilitation Treatment Specification System (RTSS) provides a framework to identify specific components of treatments developed within various rehabilitation disciplines (eg, physical, occupational, or speech-language therapy). Furthermore, this framework offers the opportunity to identify the target and active ingredients of a therapy approach as well as the mechanism of action by which it is hypothesized to effect change in abilities or functions. In this article, we apply the RTSS framework to the characterization of a sample of treatments for aphasia that are based on cognitive-linguistic models of language processing. Our discussion of these applications centers on the benefits of this classification system and additional criteria to consider when evaluating cognitive-linguistic treatments for aphasia.

An automatic sleep disorder detection based on EEG cross-frequency coupling and random forest model.

Objective. Sleep disorders are medical disorders of a subject's sleep architecture and based on their severity, they can interfere with mental, emotional and physical functioning. The most common ones are insomnia, narcolepsy, sleep apnea, bruxism, etc. There is an increased risk of developing sleep disorders in elderly like insomnia, periodic leg movements, rapid eye movement behavior disorders, sleep disorder breathing, etc. Consequently, their accurate diagnosis and classification are important steps towards an early stage treatment that could save the life of a patient.Approach. The electroencephalographic (EEG) signal is the most sensitive and important biosignal, which is able to capture the brain sleep activity that is sensitive to sleep. In this study, we attempt to analyze EEG sleep activity via complementary cross-frequency coupling (CFC) estimates, which further feed a classifier, aiming to discriminate sleep disorders. We adopted an open EEG database with recordings that were grouped into seven sleep disorders and a healthy control. The EEG brain activity from common sensors has been analyzed with two basic types of CFC.Main results. Finally, a random forest (RF) classification model was built on CFC patterns, which were extracted from non-cyclic alternating pattern epochs. Our RFCFCmodel achieved a 74% multiclass accuracy. Both types of CFC, phase-to-amplitude and amplitude-amplitude coupling patterns contribute to the accuracy of the RF model, thus supporting their complementary information.Significance. CFC patterns, in conjunction with the RF classifier proved a valuable biomarker for the classification of sleep disorders.

Sentence Recall in Latent and Anomic Aphasia: An Exploratory Study of Semantics and Syntax.

We investigated whether semantic plausibility and syntactic complexity affect immediate sentence recall in people with latent and anomic aphasia. To date, these factors have not been explored in these types of aphasia. As with previous studies of sentence recall, we measured accuracy of verbatim recall and uniquely real-time speech measures. The results showed that accuracy did not distinguish performance between latent aphasia and neurotypical controls. However, some of the real-time speech measures distinguished performance between people with latent aphasia and neurotypical controls. There was some evidence, though not pervasive, that semantic plausibility and syntactic complexity influenced recall performance. There were no interactions between semantic plausibility and syntactic complexity. The speed of preparation of responses was slower in latent aphasia than controls; it was also slower in anomic aphasia than both latent and control groups. It appears that processing speed as indexed by temporal speech measures may be differentially compromised in latent and anomic aphasia. However, semantic plausibility and syntactic complexity did not show clear patterns of performance among the groups. Notwithstanding the absence of interactions, we advance an explanation based on conceptual short-term memory as to why semantically implausible sentences are typically more erroneous and possibly also slower in recall.

Systematic review of subjective memory measures to inform assessing memory limitations after stroke and stroke-related aphasia.

AIM: Primary aims of this systematic review were to: (1) identify the range of subjective memory measures used in the stroke and stroke-related aphasia literature and (2) critically appraise their psychometric properties as well as (3) the methodological qualities of studies that included them, (4) investigate whether such measures provide an accurate reflection of memory impairments (i.e., in comparison to norms from age-matched, neurotypical participants), (5) document the representation of individuals with stroke-related aphasia, and (6) examine the extent to which subjective memory measures correlate with objective memory measures. METHODS: Systematic review of the literature from 1970 to June 2019 using a comprehensive range of relevant search terms in EMBASE, Medline, PsychINFO, SCOPUS, and Web of Science. Eligibility criteria were for studies to include adults who had suffered of clinical stroke, to report a subjective memory measure that was completed by the stroke survivors, to be reported in a peer-reviewed journal, and to be published in English or Dutch. Quality appraisal was carried out for the included studies as well as the subjective memory measures they employed. RESULTS: A total of 7,077 titles or abstracts were screened, with 41 studies included in the quantitative and qualitative synthesis. Twenty-six subjective memory measures were used in the included studies. The critical appraisal of their psychometric properties and the methodological quality of the included studies revealed significant shortcomings; for example, neurotypical participants were included in only 14 of the 41 studies. When statistical comparisons were made, different outcomes arose. Only eight studies statistically compared subjective with objective memory measures. CONCLUSIONS: This literature domain currently provides an unclear picture as to how memory limitations affect participation in stroke and stroke-related aphasia.IMPLICATIONS FOR REHABILITATIONA broad range of subjective memory measures have been used to determine stroke survivors' perceptions of their everyday memory issues.Because of psychometric weaknesses such as inadequate reliability and cross-cultural validity among subjective memory measures, there remains a need to carefully review a given measure's properties to determine if it is appropriate for use with a given stroke survivor.Stroke survivors with aphasia have been infrequently included or inadequately described in studies of subjective memory measures, and thus how these individuals perceive their everyday memory abilities requires further investigation.Although the relationship between subjective and objective memory measures has been infrequently investigated by stroke researchers, both types of measures should be considered as they likely offer complementary rather than redundant information about stroke survivors' memory abilities.

The impact of aphasia on Internet and technology use.

Purpose: This study compared Internet use post-stroke in people with aphasia (n = 25) and without aphasia (n = 17). The purpose was to understand how people with aphasia were using the Internet and to investigate the impact of aphasia on their use.Materials and methods: A face-to-face supported questionnaire explored the use of technologies, types of Internet use, traditional and Internet communication, the perception of abilities, and possible barriers to acquiring or improving Internet skills. Descriptive and inferential statistics were used to analyze the data.Results: Internet use ranged from fully independent to by proxy across both groups. Most participants perceived their aphasia as a barrier, but for the majority, it was not the sole reason for failing to acquire or improve skills. Aphasia was related to difficulties with technology-based written communication. Educational attainment was related to participant's feelings about their own skills. Whilst aphasia was important, analysis revealed that age was a stronger predictor of Internet use per se.Conclusions: It is clear that aphasia often negatively affects Internet use and proficiency. However, this research clearly demonstrates that it is important to consider the influence of factors such as age, proxy use, education, and previous technology use and experience.Implications for rehabilitationPost-stroke aphasia contributes negatively to Internet use, particularly in the use of online communication tools such as email and messaging services.Sub-groups of people with aphasia are likely to be more vulnerable to exclusion from the benefits of the Internet; specifically, older people and those with lower levels of educational attainment.It is common for both older adults with and without aphasia to use the Internet via a proxy. Independent use may not always be the desired goal within rehabilitation.People with aphasia may perceive their age and disability as barriers to using the Internet and may lack confidence in their own ability or potential.

Temporal and Episodic Analyses of the Story of Cinderella in Latent Aphasia.

Purpose The purpose of this study was to improve our understanding of the language characteristics of people with latent aphasia using measures that examined temporal (i.e., real-time) and episodic organization of discourse production. Method Thirty AphasiaBank participants were included (10 people with latent aphasia, 10 people with anomic aphasia, and 10 neurotypical control participants). Speech material of Cinderella narratives was analyzed with Praat software. We devised a protocol that coded the presence and duration of all speech segments, dysfluencies such as silent and filled pauses, and other speech behaviors. Using these durations, we generated a range of temporal measures such as speech, articulation, and pure word rates. Narratives were also coded into episodes, which provided information about the discourse macrostructure abilities of the participants. Results The latent aphasia group differed from controls in number of words produced, silent pause duration, and speech rate, but not articulation rate or pure word rate. Episodic organization of the narratives was similar in these 2 groups. The latent and anomic aphasia groups were similar in most measures, apart from articulation rate, which was lower in the anomic group. The anomic aphasia group also omitted more episodes than the latent aphasia group. Conclusions The differences between latent aphasia and neurotypical controls can be attributed to a processing speed deficit. We propose that this deficit results in an impaired ability to process information from multiple cognitive domains simultaneously.

The Methodological Quality of Short-Term/Working Memory Treatments in Poststroke Aphasia: A Systematic Review.

Purpose The aims of this systematic review are to provide a critical overview of short-term memory (STM) and working memory (WM) treatments in stroke aphasia and to systematically evaluate the internal and external validity of STM/WM treatments. Method A systematic search was conducted in February 2014 and then updated in December 2016 using 13 electronic databases. We provided descriptive characteristics of the included studies and assessed their methodological quality using the Risk of Bias in N-of-1 Trials quantitative scale ( Tate et al., 2015 ), which was completed by 2 independent raters. Results The systematic search and inclusion/exclusion procedure yielded 17 single-case or case-series studies with 37 participants for inclusion. Nine studies targeted auditory STM consisting of repetition and/or recognition tasks, whereas 8 targeted attention and WM, such as attention process training including n-back tasks with shapes and clock faces as well as mental math tasks. In terms of their methodological quality, quality scores on the Risk of Bias in N-of-1 Trials scale ranged from 4 to 17 ( M = 9.5) on a 0-30 scale, indicating a high risk of bias in the reviewed studies. Effects of treatment were most frequently assessed on STM, WM, and spoken language comprehension. Transfer effects on communication and memory in activities of daily living were tested in only 5 studies. Conclusions Methodological limitations of the reviewed studies make it difficult, at present, to draw firm conclusions about the effects of STM/WM treatments in poststroke aphasia. Further studies with more rigorous methodology and stronger experimental control are needed to determine the beneficial effects of this type of intervention. To understand the underlying mechanisms of STM/WM treatment effects and how they relate to language functioning, a careful choice of outcome measures and specific hypotheses about potential improvements on these measures are required. Future studies need to include outcome measures of memory functioning in everyday life and psychosocial functioning more generally to demonstrate the ecological validity of STM and WM treatments.

Equipping Nurses and Care Staff to Manage Mealtime Difficulties in People With Dementia: A Systematic Scoping Review of Training Needs and Interventions.

Purpose Mealtime difficulties are prevalent in dementia, posing major challenges to people with dementia (PWD), carers, and clinical services. Speech-language pathologists have a recognized role in providing training to carers of PWD who have mealtime difficulties. The aims of this study are (a) to identify the training needs of nurses and care staff with regard to managing mealtime difficulties in PWD, (b) to describe existing training interventions on this topic, and (c) to investigate the extent to which these interventions are relevant to the needs of nurses and care staff. Method A systematic search was carried out to identify studies relevant to the aims of the review. Data were extracted and then synthesized using thematic analysis and a synthesis matrix. Study quality was appraised using a validated appraisal tool. Results Various themes were identified in relation to the training needs of nurses and other care staff who manage mealtime difficulties in PWD. These were as follows: person-centered care; dealing with uncertainty; strategies, skills, and knowledge; and creating the right environment. Existing training interventions were described and compared against the training needs. The review found some correspondence between interventions and staff needs, but also some gaps. Conclusions Training interventions on this topic should be more systematically developed and better reported to facilitate effective implementation. Evidence to date indicates that training should do more to help staff deal with uncertainty. Further research assessing the benefits of speech-language pathologists' involvement in the development of training interventions is recommended because of this profession's specialist skills and knowledge with regard to both dysphagia and communication.

Short-term memory span in aphasia: Insights from speech-timing measures.

Auditory-verbal short-term memory impairments are part and parcel of aphasia and interfere with linguistic processing. To date, the science about short-term memory impairments in aphasia has been generated and dominated by studying measures of accuracy, that is, span length. Because accuracy is expressed through speech, examining the speech-timing characteristics of persons with aphasia as they engage in spoken recall could reveal insights about the manner in which accuracy is achieved. Six speech-timing measures (e.g., response durations, pause durations) were elicited from the speech waveform of word span tasks from twelve people with aphasia. Speech-timing measures were compared to neuro-typical control participants. Speech-timing performance between erroneous and correct responses in the aphasia group was also examined. Across all measures, people with aphasia produced considerably longer speech-timing patterns in comparison to control participants. Memory load affected some measures in people with aphasia and control participants. Speech-timing in correct response trials was shorter than responses in erroneous trials. Memory span correlated only with one measure, namely, speech time (defined as the sum of each individual word duration in a response). Speech time also correlated with the following measures: Aphasia severity (Aphasia Quotient of the Western Aphasia Battery), spontaneous speech, and language comprehension (also measured by the Western Aphasia Battery). Some protracted speech-timing patterns in the aphasia group may be explained by a deregulation of activation-decay patterns. However, in the absence of further evidence from people with aphasia, possible issues around the sensitivity of some speech-timing measures limit firmer conclusions. Speech-timing measures are response-time measures, which have not been systematically studied in studies of short-term or working memory in aphasia and as such, can push the current boundaries of knowledge of short-term and working memory impairments in aphasia, not only in stroke related aphasia but also other neurological conditions.

An International Survey of Assessment Practices for Short-Term and Working Memory Deficits in Aphasia.

Purpose: Recent research has highlighted the clinical relevance of understanding the nature of short-term memory (STM) and working memory (WM) deficits in persons with aphasia and the way these deficits affect linguistic processing and functional communication in activities of daily living. The psychometric properties of tests commonly used to identify STM/WM problems in individuals with aphasia, however, have been questioned. No previous study has sought to investigate assessment practices and attitudes by speech-language pathologists involved in aphasia management. Accordingly, the aims of this study were (a) to investigate both attitudes toward STM/WM assessment in individuals with aphasia, as well as the types and frequency of STM/WM tests used with individuals with aphasia, and (b) to explore factors (e.g., educational background) that may influence STM/WM assessment practices. Method: Respondents recruited via professional and aphasia support organizations completed an online survey. The survey elicited information about the respondents' demographic and clinical backgrounds and STM/WM assessment clinical practices and views, including frequency and preferred use of specific STM/WM tests. Results: The majority of respondents reported regular use of STM/WM tests as part of aphasia management. Positive attitudes toward STM/WM assessments were also reported. The most popular rankings of tests were the Cognitive Linguistic Quick Test (Helm-Estabrooks, 2001), the Comprehensive Aphasia Test (Swinburn, Porter, & Howard, 2005), and the Token Test (McNeil & Prescott, 1978). Results suggested limited knowledge about measures that assess self-perceptions of functional memory abilities. Regression analyses showed that the frequency of reported STM/WM test use was similar between clinicians and dual-role researchers/clinicians, but their attitudes toward the value of STM/WM differed. U.S. and UK respondents reported similar assessment practices. Conclusions: It is reassuring that STM/WM is taken into consideration by clinicians when providing aphasia management. Two of the most popular tests, however, have poor psychometric properties, and caution should be exercised in clinical decision making. The different value placed on STM/WM testing by clinicians and researchers/clinicians has implications for continuing professional development.

A novel, fast and efficient single-sensor automatic sleep-stage classification based on complementary cross-frequency coupling estimates.

OBJECTIVE: Limitations of the manual scoring of polysomnograms, which include data from electroencephalogram (EEG), electro-oculogram (EOG), electrocardiogram (ECG) and electromyogram (EMG) channels have long been recognized. Manual staging is resource intensive and time consuming, and thus considerable effort must be spent to ensure inter-rater reliability. As a result, there is a great interest in techniques based on signal processing and machine learning for a completely Automatic Sleep Stage Classification (ASSC). METHODS: In this paper, we present a single-EEG-sensor ASSC technique based on the dynamic reconfiguration of different aspects of cross-frequency coupling (CFC) estimated between predefined frequency pairs over 5 s epoch lengths. The proposed analytic scheme is demonstrated using the PhysioNet Sleep European Data Format (EDF) Database with repeat recordings from 20 healthy young adults. We validate our methodology in a second sleep dataset. RESULTS: We achieved very high classification sensitivity, specificity and accuracy of 96.2 ±â€¯2.2%, 94.2 ±â€¯2.3%, and 94.4 ±â€¯2.2% across 20 folds, respectively, and also a high mean F1 score (92%, range 90-94%) when a multi-class Naive Bayes classifier was applied. High classification performance has been achieved also in the second sleep dataset. CONCLUSIONS: Our method outperformed the accuracy of previous studies not only on different datasets but also on the same database. SIGNIFICANCE: Single-sensor ASSC makes the entire methodology appropriate for longitudinal monitoring using wearable EEG in real-world and laboratory-oriented environments.

The use of standardised short-term and working memory tests in aphasia research: a systematic review.

Impairments of short-term and working memory (STM, WM), both verbal and non-verbal, are ubiquitous in aphasia. Increasing interest in assessing STM and WM in aphasia research and clinical practice as well as a growing evidence base of STM/WM treatments for aphasia warrant an understanding of the range of standardised STM/WM measures that have been utilised in aphasia. To date, however, no previous systematic review has focused on aphasia. Accordingly, the goals of this systematic review were: (1) to identify standardised tests of STM and WM utilised in the aphasia literature, (2) to evaluate critically the psychometric strength of these tests, and (3) to appraise critically the quality of the investigations utilising these tests. Results revealed that a very limited number of standardised tests, in the verbal and non-verbal domains, had robust psychometric properties. Standardisation samples to elicit normative data were often small, and most measures exhibited poor validity and reliability properties. Studies using these tests inconsistently documented demographic and aphasia variables essential to interpreting STM/WM test outcomes. In light of these findings, recommendations are provided to foster, in the future, consistency across aphasia studies and confidence in STM/WM tests as assessment and treatment outcome measures.

Mining Time-Resolved Functional Brain Graphs to an EEG-Based Chronnectomic Brain Aged Index (CBAI).

The brain at rest consists of spatially and temporal distributed but functionally connected regions that called intrinsic connectivity networks (ICNs). Resting state electroencephalography (rs-EEG) is a way to characterize brain networks without confounds associated with task EEG such as task difficulty and performance. A novel framework of how to study dynamic functional connectivity under the notion of functional connectivity microstates (FCµstates) and symbolic dynamics is further discussed. Furthermore, we introduced a way to construct a single integrated dynamic functional connectivity graph (IDFCG) that preserves both the strength of the connections between every pair of sensors but also the type of dominant intrinsic coupling modes (DICM). The whole methodology is demonstrated in a significant and unexplored task for EEG which is the definition of an objective Chronnectomic Brain Aged index (CBAI) extracted from resting-state data (N = 94 subjects) with both eyes-open and eyes-closed conditions. Novel features have been defined based on symbolic dynamics and the notion of DICM and FCµstates. The transition rate of FCµstates, the symbolic dynamics based on the evolution of FCµstates (the Markovian Entropy, the complexity index), the probability distribution of DICM, the novel Flexibility Index that captures the dynamic reconfiguration of DICM per pair of EEG sensors and the relative signal power constitute a valuable pool of features that can build the proposed CBAI. Here we applied a feature selection technique and Extreme Learning Machine (ELM) classifier to discriminate young adults from middle-aged and a Support Vector Regressor to build a linear model of the actual age based on EEG-based spatio-temporal features. The most significant type of features for both prediction of age and discrimination of young vs. adults age groups was the dynamic reconfiguration of dominant coupling modes derived from a subset of EEG sensor pairs. Specifically, our results revealed a very high prediction of age for eyes-open (R2 = 0.60; y = 0.79x + 8.03) and lower for eyes-closed (R2 = 0.48; y = 0.71x + 10.91) while we succeeded to correctly classify young vs. middle-age group with 97.8% accuracy in eyes-open and 87.2% for eyes-closed. Our results were reproduced also in a second dataset for further external validation of the whole analysis. The proposed methodology proved valuable for the characterization of the intrinsic properties of dynamic functional connectivity through the age untangling developmental differences using EEG resting-state recordings.

Topological Filtering of Dynamic Functional Brain Networks Unfolds Informative Chronnectomics: A Novel Data-Driven Thresholding Scheme Based on Orthogonal Minimal Spanning Trees (OMSTs).

The human brain is a large-scale system of functionally connected brain regions. This system can be modeled as a network, or graph, by dividing the brain into a set of regions, or "nodes," and quantifying the strength of the connections between nodes, or "edges," as the temporal correlation in their patterns of activity. Network analysis, a part of graph theory, provides a set of summary statistics that can be used to describe complex brain networks in a meaningful way. The large-scale organization of the brain has features of complex networks that can be quantified using network measures from graph theory. The adaptation of both bivariate (mutual information) and multivariate (Granger causality) connectivity estimators to quantify the synchronization between multichannel recordings yields a fully connected, weighted, (a)symmetric functional connectivity graph (FCG), representing the associations among all brain areas. The aforementioned procedure leads to an extremely dense network of tens up to a few hundreds of weights. Therefore, this FCG must be filtered out so that the "true" connectivity pattern can emerge. Here, we compared a large number of well-known topological thresholding techniques with the novel proposed data-driven scheme based on orthogonal minimal spanning trees (OMSTs). OMSTs filter brain connectivity networks based on the optimization between the global efficiency of the network and the cost preserving its wiring. We demonstrated the proposed method in a large EEG database (N = 101 subjects) with eyes-open (EO) and eyes-closed (EC) tasks by adopting a time-varying approach with the main goal to extract features that can totally distinguish each subject from the rest of the set. Additionally, the reliability of the proposed scheme was estimated in a second case study of fMRI resting-state activity with multiple scans. Our results demonstrated clearly that the proposed thresholding scheme outperformed a large list of thresholding schemes based on the recognition accuracy of each subject compared to the rest of the cohort (EEG). Additionally, the reliability of the network metrics based on the fMRI static networks was improved based on the proposed topological filtering scheme. Overall, the proposed algorithm could be used across neuroimaging and multimodal studies as a common computationally efficient standardized tool for a great number of neuroscientists and physicists working on numerous of projects.