1,720,960 research outputs found
HIGH ORDER VISUOPERCEPTUAL IMPAIRMENTS UNDERSCORE SPECIFIC PERCEPTUAL PERFORMANCES ON ILLUSORY FIGURES IN PATIENTS WITH PARKINSON’S DISEASE: IMPLICATIONS FOR VISUAL HALLUCINATIONS
No full textLe allucinazioni visive sono definibili come esperienze percettive che si producono in assenza di stimolazione effettiva dell’organo di senso. Esse costituiscono un sintomo non-motorio particolarmente prevalente e potenzialmente invalidante della malattia di Parkinson, che può interessare sino al 70% di questi pazienti. La fisiopatologia di questi fenomeni non è ancora nota nel dettaglio. Si ritiene tuttavia che il progressivo deterioramento delle funzioni visive afferenti possa comportare la graduale attivazione di meccanismi percettivi superiori coinvolti nella modulazione dell’attenzione visiva, nel reperimento di referenze visive pregresse e nella soppressione di potenziali stimoli interferenti. Tali funzioni “top-down” non sarebbero però sufficienti nè adeguate per compensare sistematicamente alla perdita di qualità dell’informazione visiva. Ciò faciliterebbe, nel tempo, l’emergere di esperienze percettive erronee.
In psicologia percettiva, le illusioni rappesentano fenomeni di erronea interpretazione dello stimolo visivo. Esse possono essere elicitate sistematicamente attraverso la manipolazione parametrica di alcune variabili dello stimolo visivo quali luminanza, colore, risoluzione temporale, configurazione spaziale ecc. Tali fenomeni non possiedono valenza patologica di per se, in quanto sono attribuili alle fisiologiche caratteristiche computazionali del sistema visivo umano. In tale contesto, la performance percettiva dell’individuo in risposta a stimoli illusori può fornire importanti informazioni circa i processi neurofisiologici alla base della percezione visiva cosciente.
Il presente progetto di ricerca si è articolato attraverso uno studio esplorativo osservazionale in singolo cieco avente come scopo la caratterizzazione della performance percettiva di una popolazione di pazienti affetti da malattia di Parkinson di grado moderato e senza significativa disfunzione cognitiva. I pazienti sono stati suddivisi in due gruppi, rispettivamente con (PD_Hal) e senza (PD-NonHal) storia di allucinazioni visive, sulla base del punteggio a un questionario dedicato (University of Miami Parkinson’s Disease Hallucinations Questionnaire), ottimizzato per il riconoscimento delle allucinazioni visive tipicamente sperimentate da questi pazienti.
Successivamente, sono state somministrate due figure illusorie computerizzate ritenute in grado di ingaggiare direttamente funzioni percettive verosimilmente intaccate dal processo neurodegenerativo associato alla malattia di Parkinson: l’illusione di DelBoeuf e l’illusione di restringimento da completamento amodale. Le potenziali differenze nella performance percettiva elicitata in risposta a tali stimoli sono state analizzate e confrontate con quelle di un guppo di controlli sani di pari età. Inoltre, il presente progetto di ricerca ha esplorato i sostrati neurali alla base delle possibili differenze percettive trai pazienti mediante lo studio nelle differenze nel metabolismo regionale corticale con tomografia per emissione di positroni (PET). I risultati originali di questa sperimentazione suggeriscono che, nei pazienti senza storia di allucinazioni visive, le alterazioni visuospaziopercettive associate alla malattia di Parkinson comportino un profilo di paradossale resilienza a stimoli illusori che nei soggetti sani normalmente implicano una integra rappresentazione della scena visiva globale e un adeguato shift attentivo. Tale pattern non risulta rilevabile nei pazienti con storia di allucinazioni visive, i quali, per contro, manifestano una maggior vulnerabilità a stimoli illusori che normalmente vengono contrastati, nei soggetti sani, da funzioni percettive quali segregazione figura/contrasto e identificazione di figure sovrapposte
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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