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Neurodegenerative disorders of language and speech: Non-language-dominant diseases
No full textSpeech and language networks span vast cortical and subcortical regions in the human brain, including putative perisylvian areas but extending well beyond them. Accordingly, relevant functions can be compromised by diverse neural disruptions even in non-language-dominant neurodegenerative diseases (nldNDs) i.e., conditions that are not primarily typified by speech or language dysfunction. The present chapter offers a systematic overview of this topic, focusing on the three most prevalent nldNDs (Alzheimers disease, Parkinsons disease, and behavioral variant frontotemporal dementia). In each case, we offer detailed descriptions of spared and impaired skills across speech/language levels (phonetics, phonology, lexicosemantics, morphosyntax, discourse-level processing) and multidimensional accounts of their core neural signatures (including patterns of brain atrophy and tractographic abnormalities as well as alterations in regional activation, functional connectivity, event-related potentials, and oscillatory modulations). Next, we offer a brief contrastive summary of the core patterns in each disease. Finally, we address the main implications of the evidence and the prime challenges facing the field in the immediate future. Briefly, this chapter provides a fine-grained, multimodal, transnosological view of speech and language disruptions beyond the diseases typically associated with them.Fil: García, Adolfo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Educación Elemental y Especial; Argentina. Universidad de San Andrés; Argentina. University of California; Estados UnidosFil: DeLeon, Jessica. University of California; Estados UnidosFil: Tee, Boon Lead. University of California; Estados Unido
A systematic review of the quantitative markers of speech and language of the frontotemporal degeneration spectrum and their potential for cross-linguistic implementation
Full text linkFrontotemporal dementia (FTD) is a neurodegenerative disease spectrum with an urgent need for reliable biomarkers for early diagnosis and monitoring. Speech and language changes occur in the early stages of FTD and offer a potential non-invasive, early, and accessible diagnostic tool. The use of speech and language markers in this disease spectrum is limited by the fact that most studies investigate English-speaking patients. This systematic review examines the literature on psychoacoustic and linguistic features of speech that occur across the FTD spectrum across as many different languages as possible. 76 papers were identified that investigate psychoacoustic and linguistic markers in discursive speech. 75 % of these papers studied English-speaking patients. The most generalizable features found across different languages, are speech rate, articulation rate, pause frequency, total pause duration, noun-verb ratio, and total number of nouns. While there are clear interlinguistic differences across patient groups, the results show promise for implementation of cross-linguistic markers of speech and language across the FTD spectrum particularly for psychoacoustic features.</p
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Primary progressive aphasia: a model for neurodegenerative disease.
Full text linkPURPOSE OF REVIEW: Knowledge on primary progressive aphasia (PPA) has expanded rapidly in the past few decades. Clinical characteristics, neuroimaging correlates, and neuropathological features of PPA are better delineated. This facilitates scientific studies on the disease pathophysiology and allows speech and language therapy to be more precisely targeted. This review article begins with a summary of the current understanding of PPA and discusses how PPA can serve as a model to promote scientific discovery in neurodegenerative diseases.
RECENT FINDINGS: Studies on the different variants of PPA have demonstrated the high compatibility between clinical presentations and neuroimaging features, and in turn, enhances the understanding of speech and language neuroanatomy. In addition to the traditional approach of lesion-based or voxel-based mapping, scientists have also adopted functional connectivity and network topology approaches that permits a more multidimensional understanding of neuroanatomy. As a result, pharmacological and cognitive therapeutic strategies can now be better targeted towards specific pathological/molecular and cognitive subtypes.
SUMMARY: Recent scientific advancement in PPA potentiates it to be an optimal model for studying brain network vulnerability, neurodevelopment influences and the effects of nonpharmacological intervention in neurodegenerative diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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