1,720,977 research outputs found
Anatomy of oral apraxia and speech apraxia: A VLSM study in a cohort of left-hemisphere brain-damaged patients
No full textThe neural bases of limb and oral apraxia: A VLSM study in a cohort of left-hemisphere brain-damaged patients
No full textIntroduction : Notwithstanding the high number of experimental studies examining limb and oral apraxia from a
clinical, cognitive (Tessari et al., 2004) and neuroimaging point of view, the neural mechanisms underlying this
impairment are still little clarified. Motor programming abilities have been recently investigated with f-MRI
techniques (Martin et al., 2016) but lesions-to-symptoms mapping is still a fundamental method to underpin the
anatomical basis of complex behaviors (Goldenberg et al., 2015). The aim of the present study is to investigate
the anatomical basis of ideomotor, ideational, and oral apraxia in a cohort of left-hemisphere brain-damaged
patients using the subtraction and voxel-based lesion-symptom mapping (VLSM) localization procedures.
Methods : Ideomotor (arm and hand movements vs. finger movements), ideational and oral apraxia were studied
through an anatomo-clinical correlative procedure in a sample of 48 left-hemisphere brain-damaged patients.
Subtraction and VLSM procedures were used to localize the anatomical bases of these impairments.
Results : Lesions of the left supramarginal gyrus and of the left angular gyrus were associated with ideomotor
apraxia of the upper limb and hand; lesions of the left supramarginal gyrus and of the left middle frontal gyrus
were associated with ideomotor apraxia of finger movement. Ideational apraxia was associated with lesions of
the left supramarginal gyrus, left middle frontal gyrus and left inferior frontal gyrus (pars opercularis) suggesting
a partial common neural substrate with ideomotor apraxia. A network of left perisylvian areas did emerge as
anatomical correlate of oral apraxia, including the left insular cortex, and the left frontal and central opercula,
the left inferior frontal gyrus (pars opercularis).
Discussion : Our results confirm the existence of relatively independent anatomical specializations in the left
hemisphere (Basso et al., 1985; Mengotti et al., 2015), with regards to the hierarchical level of limb apraxia
(ideational vs. ideomotor), body parts (upper limb and hand vs. finger movements), and of oral apraxia (Tognola
& Vignolo, 1980).
References : Goldenberg G. Neuropsychologia (2015) 75: 40-49.
Martin M. Brain (2016) 139: 1497-1516.
Mengotti P. Neuropsychologia (2015) 79: 256-27
Types of dyslexia in aphasia: A multiple single-case study in a shallow orthography language.
No full textReading disorders in a language with shallow orthography: A multiple single-case study in Italian.
No full text
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
- …
