1,720,959 research outputs found
Evidence for specific cognitive deficits in visual information processing in patients with OCD compared to patients with unipolar depression
No full textObjective: Neuropsychological studies comparing cognitive performance in patients suffering from Obsessive-Compulsive Disorder (OCD) or Major Depressive Disorder (MDD) revealed deficits in the domains of verbal fluency and viso-motor speed/set shifting in both groups. Spatial working memory deficits, however, have been identified as specific markers of OCD. As yet, it has not been substantiated whether deficits in visual organization and complex visual memory are also specific to OCD and are not shared by MDD. Method: Test performance in seven cognitive domains was assessed in 40 OCD patients, 20 MDD patients, and 40 healthy controls. Patient groups were matched according to severity of depressive symptoms. Results: Deficits shared by both patient groups, as compared to controls, were found in delayed spatial recall and verbal fluency while verbal memory was normal in both patient groups. Only patients with OCD, but not MDD patients were impaired in the domains visual memory, viso-motor speed/set shifting, visual organization, and problem solving. In addition, OCD patients differed significantly from MDD subjects in visual organization and problem solving. Visual organization scores correlated significantly with severity of current compulsions in the OCD group (r=.324). Conclusions: OCD patients demonstrate difficulties in visual organization and mental manipulation of complex visual material, which are not accounted for by depressive symptoms and which constitute a specific cognitive deficit of the disorder. (C) 2010 Elsevier Inc. All rights reserved.Deutsche Forschungsgemeinschaft (DFG
Antisaccade performance in patients with obsessive-compulsive disorder and unaffected relatives: further evidence for impaired response inhibition as a candidate endophenotype
No full textCognitive dysfunctions such as inhibitory deficits and visuospatial abnormalities are often found in patients with obsessive-compulsive disorder (OCD). Recent findings in unaffected relatives indicate that response inhibition and other neuropsychological functions may also constitute endophenotypes of OCD. In the present study, 30 OCD patients, 30 first-degree relatives, and 30 healthy control subjects were assessed using a comprehensive neuropsychological test battery. A subsample of 21 subjects of each group also performed an antisaccade task. The samples were matched according to age, gender, education, and verbal intelligence. The OCD patients and the unaffected OCD relatives showed increased antisaccade error rates compared with the healthy control group (p = 0.003, p = 0.028, respectively). Significantly prolonged antisaccade latencies as compared to prosaccade latencies were only found in the OCD patients compared with the healthy control group (p = 0.019). Only OCD patients but not the unaffected OCD relatives were impaired with regard to visuospatial functions, problem-solving, and processing speed. Antisaccade errors did not correlate with severity of OCD or depressive symptoms. This study confirms inhibitory deficits, as indicated by increased antisaccade error rates, as a candidate endophenotype of OCD. In agreement with previous findings from imaging studies, our data suggest that functional abnormalities in frontostriatal and parietal cortical regions form part of the vulnerability for OCD.Deutsche Forschungsgemeinschaft (DFG
Neuropsychologische Endophänotypen der Schizophrenie : Neurokognitive und neuromotorische Normabweichungen bei wahrscheinlichen Anlageträgern für Schizophrenie
No full textEinleitung: Die Schizophrenie ist eine klinisch heterogene und ätiologisch komplex determinierte psychiatrische Erkrankung. Die Identifikation von Endophänotypen – genetisch mit der Erkrankung assoziierten Normvarianten – kann eine Brücke zwischen dem Phänotyp und dem Genotyp schlagen, und so der weiteren molekulargenetischen Aufklärung der Erkrankung dienen. Neuropsychologische Störungen gehören zu den Kernmerkmalen der Schizophrenie, was sie potentiell zu geeigneten Kandidaten für die Suche nach endophänotypischen Markern für diese Erkrankung macht. In besonderem Maße informativ für die Suche nach Endophänotypen ist die Untersuchung sogenannter „more likely carrier“ (MLC) – eher wahrscheinlicher Anlageträger – bei denen aufgrund der familiären Position von einem hohen genetisch vermittelten Risiko ausgegangen werden kann. Nur eine einzige Studie untersuchte bislang neuropsychologische Leistungen bei wahrscheinlichen Anlageträgern für die Schizophrenie; die Stichprobe umfasste acht MLC.Methode: Es wurden 25 Patienten mit einer Schizophrenie vom paranoiden Typus (nach DSM-IV), 55 Eltern schizophren Erkrankter ohne eine Lebenszeitdiagnose einer psychotischen Störung, darunter 13 eher wahrscheinliche Anlageträger (MLC) und 11 weniger wahrscheinliche Anlageträger (LLC), sowie 80 Kontrollprobanden neuropsychologisch untersucht. Eingesetzt wurden Verfahren zur Erfassung von Aufmerksamkeits-, Gedächtnis- und Exekutivfunktionen sowie neuromotorischen Störungen.Ergebnisse: Die schizophrenen Patienten wiesen in allen neuropsychologischen Funktionsbereichen signifikante Beeinträchtigungen auf; der alle neurokognitiven Variablen zusammenfassende Globale Kognitive Index ergab eine signifikante Normabweichung von etwa zwei Standardabweichungen. Die biologischen Eltern schizophren Erkrankter zeigten ebenfalls bedeutsame – wenn auch im Vergleich zu den Patienten quantitativ geringere – neuropsychologische Defizite in allen erfassten Bereichen; bei ihnen fand sich im Globalen Kognitiven Index eine signifikante Normabweichung von etwa einer halben Standardabweichung. Besonders interessant waren die differentiellen Befunde zu den neuropsychologischen Leistungen der als eher wahrscheinliche (MLC) versus weniger wahrscheinliche (LLC) Anlageträger klassifizierten Elternteile. Während die MLC ausgeprägte Normabweichungen in allen drei erfassten kognitiven Funktionsbereichen – dem Gedächtnis, den Exekutivfunktionen und (ohne Ausschlüsse) auch der Aufmerksamkeit – sowie im neuromotorischen Bereich zeigten, wiesen die LLC ausschließlich im Bereich des Gedächtnisses signifikante Beeinträchtigungen auf. Der Globale Kognitive Index ergab bei den MLC eine signifikante Normabweichung von etwa einer Standardabweichung, bei den LLC war die Abweichung nicht bedeutsam. Der direkte Vergleich der beiden genetisch unterschiedlich belasteten Elterngruppen erbrachte besonders ausgeprägte und signifikante Leistungsdifferenzen im exekutiven Funktionsbereich. Die neuropsychologischen Defizite bei den Eltern schizophren Erkrankter zeigten sich als unabhängig von schizophrenierelevanten psychopathologischen Auffälligkeiten. Eine geschlechtsspezifische Analyse der Eltern-Daten ergab keine bedeutsamen geschlechtsgebundenen Effekte; Mütter und Väter schizophren Erkrankter wiesen vergleichbar stark ausgeprägte neuropsychologische Defizite auf.Schlussfolgerungen: Nach den Ergebnissen der Studie kommen in erster Linie Störungen der Exekutivfunktionen als mögliche neuropsychologische Endophänotypen der Schizophrenie, d.h. genetisch mit der Erkrankung assoziierte neuropsychologische Normvarianten, in Betracht
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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
Early onset of obsessive-compulsive disorder and associated comorbidity
No full textBackground: Previous studies have aimed to identify subtypes of obsessive-compulsive disorder (OCD) based on their age of onset (AOO). Obsessive-compulsive spectrum disorders (OCS disorders) such as tic disorders have been particularly associated with an early onset in some studies. However, subtypes of early- and late-onset OCD are unevenly determined, and the biological and the clinical validity of these subtypes are unknown. This study was undertaken to discriminate the subtypes of OCD in different AOO levels and to test the hypothesis that different AOO bands are associated with a differential pattern of comorbidity. Methods: Two hundred fifty-two patients with OCD were interviewed directly with the German version of the Schedule for Affective Disorders and Schizophrenia-Lifetime Anxiety Version, which provides DSM-IV diagnosis. Subgroups with different ages of onset were investigated (cut-off levels of 10, 15, and 18 years). Results: Subjects with an early AOO (onset <= 10 years) were significantly more likely to have OCS disorders (odds ratio [OR] = 3.46, P =. 001; 95% confidence interval [CI]: 1.72-6.96), in particular tic/Tourette's disorders (OR = 4.63; P =. 002; 95% CI. 1.78-12.05), than were late-onset subjects. Conclusions: For most mental disorders (e.g., anxiety and mood disorders), no associations with A 00 of OCD were identified. However, subjects in the early-onset group (<= 10 years) had a significant increase in comorbid tic and Tourette's disorders. Future research should examine potential neurobiological features associated with early-onset presentations of OCD. Early detection and management of comorbidities may offset impairments later in life. Depression and Anxiety 26.1012-1017, 2009. (C) 2009 Wiley-Liss, Inc
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