1,721,030 research outputs found
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
Transcranial cerebellar direct current stimulation enhances Verb Generation but not Verb Naming in Poststroke Aphasia
No full textAlthough the role of the cerebellum in motor function is well recognized, its involvement in the lexical domain remains to be further elucidated. Indeed, it has not yet been clarified whether the cerebellum is a language structure per se or whether it contributes to language processing when other cognitive com- ponents (e.g., cognitive effort, working memory) are required by the language task. Neuromodulation studies on healthy partici- pants have suggested that cerebellar transcranial direct current stimulation (tDCS) is a valuable tool to modulate cognitive func- tions. However, so far, only a single case study has investigated whether cerebellar stimulation enhances language recovery in aphasic individuals. In a randomized, crossover, double-blind de- sign, we explored the effect of cerebellar tDCS coupled with lan-
INTRODUCTION
During the past two decades, converging neuroscientific evidence has largely documented that the human cere- bellum contributes to a much wider range of higher-level cerebral functions than previously accepted. Indeed, although, traditionally, there has been a unanimous agreement that the cerebellum is primarily involved in autonomic and somatic motor processes (Leiner, 2010; Schmahmann, 2010; Strick, Dum, & Fiez, 2009; De Smet, Baillieux, De Deyn, Mariën, & Paquier, 2007; Holmes, 1939), particularly after aphasia reports, there has been a rapidly increasing interest in the cerebellum’s role in cognition (Reeber, Otis, & Sillitoe, 2013; Manto & Haines, 2012; Strick et al., 2009). Indeed, several linguistic dis- orders after acquired cerebellar lesions have been docu- mented (De Smet et al., 2007), such as impaired verbal fluency (Meinzer, Yetim, McMahon, & de Zubicaray, 2016; Stoodley & Schmahmann, 2009; Richter et al., 2007; Leggio, Silveri, Petrosini, & Molinari, 2000; Schmahmann & Sherman, 1998; Molinari, Leggio, & Silveri, 1997; Appollonio, Grafman, Schwartz, Massaquoi, & Hallett, 1993; Akshoomoff,
1Università Federico II, Naples, Italy, 2IRCCS Fondazione Santa Lucia, Rome, Italy, 3Università degli Studi di Roma Tor Vergata, Rome, Italy, 4Università degli Studi di Milano, Milan, Italy
© 2017 Massachusetts Institute of Technology
guage treatment for verb improvement in 12 aphasic individuals. Each participant received cerebellar tDCS (20 min, 2 mA) in four experimental conditions: (1) right cathodal and (2) sham stimu- lation during a verb generation task and (3) right cathodal and (4) sham stimulation during a verb naming task. Each ex- perimental condition was run in five consecutive daily sessions over 4 weeks. At the end of treatment, a significant improve- ment was found after cathodal stimulation only in the verb gen- eration task. No significant differences were present for verb naming among the two conditions. We hypothesize that cere- bellar tDCS is a viable tool for recovery from aphasia but only when the language task, such as verb generation, also demands the activation of nonlinguistic strategies
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
Stairways to the brain: Transcutaneous spinal direct current stimulation (tsDCS) modulates a cerebellar-cortical network enhancing verb recovery
No full textIt has long been assumed that the language function is hierarchically organized into specific cortical areas. Here, for the first time, we present direct evidence that the spinal cord takes part in language processing. In a randomized-double blind design, sixteen aphasics underwent a language treatment combined with transcutaneous spinal direct current stimulation (tsDCS). During the treatment, each subject received tsDCS (20 min, 2 mA) over the thoracic vertebrae (IX-X vertebrae) in two different conditions: (1) anodal, and (2) sham while performing a verb naming task. Each experimental condition was run in five consecutive daily sessions over two weeks. Before and after each condition, all patients underwent a resting state functional magnetic resonance imaging (rs-fMRI). After anodal tsDCS, significant functional connectivity changes were found in a cerebellar-cortical network recruiting regions such as the left cerebellum, the right parietal and premotor cortex known to be also involved in action-related verb processing. Indeed, this increase of connectivity significantly correlated with the greatest amount of improvement found in verb naming. In line with our experimental data, we also found a greater improvement after anodal tsDCS also on untreated items of the language test but only on tasks which required the use of verbs, such as verb naming and picture description. No significant changes were found in noun naming. Thus, this evidence emphasizes, for the first time, that the neural response due to tsDCS combined with language treatment changes during the course of recovery by enhancing activity into cortical regions which influence verb processing
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