1,721,116 research outputs found
Cortical activation during imitative behavior: An fMRI study
Full text linkA previous behavioural study on healthy subjects and callosotomized patients showed that subjects imitated mainly in mirror mode when free to choose the imitation mode, using the right limb to copy a left limb gesture of the facing model; when asked to use the same limb as the model, patients still perform in mirror mode, but controls imitated in anatomical mode, using the right limb for imitating a right limb gesture. These data suggest that the anatomical mode of imitation recruites both hemispheres, being linked to the integrity of the corpus callosum.
The present study aims at investigating with fMRI the neural correlates of imitative perspective-taking, specially the anatomical mode.
Functional MRI was performed in 10 control subjects of the previously tested groups, asked to Observe or Imagine-to-Imitate-with-the-same-limb, in separete runs, intransitive gestures. Different cortical activation in the two conditions were observed: opercular part of left inferior frontal gyrus, left inferior parietal lobule, right temporo-parietal junction and bilateral parietal opercular cortices were activated in Imagine-to-Imitate condition only.
Present data confirm previous behavioural observations and indicate that neural circuitry underpinning the anatomical imitation of intransitive gesture likely requires the cooperation of both hemispheres, and therefore the integrity of the corpus callosum
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
Imitation Strategies in Subjects With Schizophrenia: A Behavioural Approach
No full textImitation is a basic human ability, present early in life. Previous studies on control subjects and callosotomized patients showed that imitation occurred mainly in mirror-mode in both groups (60% controls, 66% patients) when they imitate without instructions (free sessions). In contrast, when asked to use the same or opposite limb as the model (driven sessions), controls used anatomical mode (93%), callosotomized patients mainly mirror strategy (61%). It has been suggested that callosotomized subjects prefer the mirror mode because of an impaired capacity for mental rotation, likely due to the lack of the corpus callosum (CC). The present research investigated the imitation strategies used by schizophrenic patients, who also could present anomaly in the interhemispheric connections. Fifteen hospitalized patients with diagnosis of schizophrenia participated in the study. They were asked to imitate upper limb intransitive meaningful and meaningless gestures performed by a model in a video. The results were compared with those from 20 healthy individuals. In driven imitation, controls answered in anatomical mode (95% of the responses), versus 63% of patients' responses. In free imitation sessions the answers in anatomical mode decreased to 39% in control subjects and to 46% in schizophrenic patients. In both driven and free imitation, the differences between the two proportions, conditioned to Diagnosis, resulted significantly different. The present data, in line with previous studies on psychotic and neurological patients showing impairments on imitation, suggest that the neural circuitry leading patients to perform differently from controls likely relates with the functional efficiency of the CC
Right hemisphere or valence hypothesis, or both? The processing of hybrid faces in the intact and callosotomized brain
No full textThe valence hypothesis and the right hemisphere hypothesis in emotion processing have been alternatively supported. To better disentangle the two accounts, we carried out two studies, presenting healthy participants and an anterior callosotomized patient with 'hybrid faces', stimuli created by superimposing the low spatial frequencies of an emotional face to the high spatial frequencies of the same face in a neutral expression. In both studies we asked participants to judge the friendliness level of stimuli, which is an indirect measure of the processing of emotional information, despite this remaining "invisible". In Experiment 1 we presented hybrid faces in a divided visual field paradigm using different tachistoscopic presentation times; in Experiment 2 we presented hybrid chimeric faces in canonical view and upside-down. In Experiments 3 and 4 we tested a callosotomized patient, with spared splenium, in similar paradigms as those used in Experiments 1 and 2. Results from Experiments 1 and 3 were consistent with the valence hypothesis, whereas results of Experiments 2 and 4 were consistent with the right hemisphere hypothesis. This study confirms that the low spatial frequencies of emotional faces influence the social judgments of observers, even when seen for 28 ms (Experiment 1), possibly by means of configural analysis (Experiment 2). The possible roles of the cortical and subcortical emotional routes in these tasks are discussed in the light of the results obtained in the callosotomized patient. We propose that the right hemisphere and the valence accounts are not mutually exclusive, at least in the case of subliminal emotion processing
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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