1,720,995 research outputs found
Writing errors in primary progressive aphasia
No full textPeripheral errors in writing, that is errors produced download the spelling, have been occasionally described in primary progressive aphasia (PPA), but the possibility that these errors might be a marker of parkinsonism associated to some subtypes of PPA has not been explored. We investigated whether errors of peripheral nature characterize the writing disorder in PPA when associated with parkinsonian signs (PSs). Subgroups of PPA without PSs and with PSs were studied. The proportion of the central and peripheral errors in writing words and pseudowords was calculated in each group. In writing words, central errors significantly exceeded peripheral errors in subgroups without PSs. The higher the number of peripheral errors, the higher the probability of presenting PSs. No relation emerged between any error and the Unified Parkinson’s Disease Rating Scale, but both types of errors correlated with measures of cognitive ability. Peripheral errors emerge when PSs are associated with PPA and may be linked to a decay of the cognitive control on movement, possibly involving the right hemisphere. Peripheral errors have clinical relevance in PPA, to the extent that they may assume the significance of a marker of specific subtypes and can help to outline the specific clinical picture of individual patients
Emotional valence may influence memory performance for visual artworks in Parkinson’s disease
No full textBackground: Non-motor symptoms in Parkinson’s disease (PD) include reduced reactivity to emotional stimuli. Visual artworks can evoke emotional responses. Motor, sensorial and cognitive networks implicated in the aesthetic experience and in the emotional-reward domain show a significant overlap with the pathological nigrostriatal, mesocortical and mesolimbic circuitry that characterises PD. Methods: Memory enhancement by emotional stimuli such as visual artwork-stimuli was explored in 12 right-sided and 12 left-sided non-demented-PD patients, 12 Alzheimer’s disease patients (AD) and 13 healthy controls (HC). Ten emotional and 10 non-emotional stimuli were previously identified based on the ratings of the emotional impact provided by 45 non-PD subjects on 82 pictures of paintings. Only figurative artworks were included. Patients and HC were requested to rate on a 7-point scale the emotional impact of 20 pictures; they were then requested to recognise the 20 pictures amongst 20 distractors (incidental memory task). Results and Conclusion: Recognition of emotional stimuli was more accurate compared to non-emotional stimuli in AD, left-sided PD and HC; right-sided PD did not show sensitivity to the emotional valence of the stimuli suggesting the involvement of the nigrostriatal, mesocortical and mesolimbic circuitry of the left hemisphere in the emotional-reward system related to the aesthetic experience
Impaired processing of conspecifics in Parkinson’s disease
No full textExperimental evidence indicates that the inferior frontal gyrus (IFG) processes emotional/affective features crucial to elaborate knowledge about social groups and that knowledge of social concepts is stored in the anterior temporal lobe (ATL). We investigated whether knowledge about social groups is impaired in Parkinson's disease (PD), in which dysfunctional connectivity between IFG and ATL has been demonstrated. PD patients (N = 20) and healthy controls (HC, N = 16) were given a lexical decision task in a semantic priming paradigm: the prime-targets included 144 words and 144 pseudowords, each preceded by three types of prime ("animals," "things," "persons"). Out of these 288 prime-targets, forty-eight were congruent (same category) and 96 incongruent (different category). Out of 48 congruent prime-targets, 24 denoted social items and 24 nonsocial items. Thus, four types of trials were obtained: congruent social; congruent nonsocial; incongruent social; incongruent nonsocial. Congruent target-words were recognized better than incongruent target-words by all groups. The semantic priming effect was preserved in PD; however, accuracy was significantly lower in PD than in HC in social items. No difference emerged between the two groups in nonsocial items. Impaired processing of words denoting social groups in PD may be due to impairment in accessing the affective/emotional features that characterize conceptual knowledge of social groups, for the functional disconnection between the IFG and the ATL
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
Measuring the effect of rhythmic auditory stimuli on parkinsonian gait in challenging settings
No full textRhythmic auditory stimuli (RAS) improve the disabling motor symptom of Parkinson's disease patients. In the large majority of studies, the effect of RAS has been assessed during common activities such as walking and turning. However, how RAS modulates parkinsonian behaviors in more challenging settings of daily living and whether a machine learning algorithm could classify them remains unclear. Eleven patients with idiopathic PD (age 72±7 years) were asked to walk under four conditions: straight walking, walking over an irregular surface, walking within a narrow pathway, and walking along a curving path (eight-shaped), with and without external stimulation. RAS pace was set at 110% of the normal cadence and spatio-temporal gait parameters were measured through two inertial measurement units placed on feet. k-Nearest Neighbor (k-NN) algorithm, with and without principal component analysis (PCA) as feature selector, was used for the classification of walking conditions. Cadence, gait speed, and gait time improved during RAS walking, regardless of challenging walking conditions. On the contrary, stride length increased only in straight walking, while gait speed showed improvement also in walking over an irregular surface and walking within narrow pathway conditions. k-NN algorithm reported higher accuracy (72.4%) in the classification of eight- shaped curving path both considering the overall feature set and a reduced one. These results open to the possibility of measuring RAS-induced effects on PD mobility in an ecological scenario and improving their administration based on the actual motor activity
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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