1,721,040 research outputs found
Migraine in childhood: biobehavioural or psychosomatic disorder?
No full textIt is well documented that headache is a multifactorial disorder which includes not only genetic, biological, medical and neuropsychological factor but also psychological and personality traits. The close relationship between stress and migraine attacks and the significant psychiatric comorbidities in migraine provide evidence of a "paradigm" of tight interaction between somatic and psychological aspects in paediatric migraine. In particular in younger children, an uncomfortable situation, a psychological problem or an emotional distress is rarely expressed directly but usually through physical symptoms. So migraine may be considered as a disorder of psychobiological adaptation in which genetic predisposition interplays with internal and/or external environmental influences such as psycho-emotional, climatic, hormonal, dietary or other factors
Intracortical Inhibition and Facilitation in Migraine-A Transcranial Magnetic Stimulation Study
No full textObjective.-Migraine is a disease of altered cortical excitability between attacks. However, the mechanisms of abnormal excitability in migraine are insufficiently investigated. Hence, the aim of the study was to investigate intracortical inhibition/facilitation of the motor circuit in migraine. Methods.-Sixteen women suffering from migraine without aura and 15 healthy women were investigated using a suprathreshold transcranial magnetic stimulation (TMS) in the paired-pulse paradigm with long interstimulus intervals (ISI = 20, 60, 120 ms) and measurement of the cortical silent period. Results.-We found no differences for the cortical silent period and for the long intracortical inhibition between the groups. Concerning intracortical facilitation, this ability was significantly more pronounced in patients suffering from migraine compared with healthy controls. Conclusion.-Migraineurs produce an increased intracortical facilitation. The results may be discussed in line of glutamatergic mechanisms in migraine, which could be related to altered facilitation
Neural correlates of affective empathy and reinforcement learning in boys with conduct problems: fMRI evidence from a gambling task
No full textBackground Conduct problems (CP) comprise abnormal behaviors associated with aberrant aspects of affective empathy as well as learning. However, behavioral measures for affective empathy are challenging, and previous results concerning learning in patients with CP are inconsistent. Methods Nineteen boys with CP and 24 typically developing (TD) boys aged 11–17 years (M = 14.34, SD = 1.93) participated in the study. An ultimatum-game was applied in order to elicit the feeling of like or dislike towards the opponent for a subsequent gambling task, which was played by the opponents (OTHER-condition) and by the participants themselves (SELF-condition). Functional MRI data were recorded throughout the experiment. Results In accordance with the model of insensitivity to punishment, hypo-activation of the left amygdala, left anterior insula, ventral medial prefrontal cortex (MPFC), and bilateral temporo-parietal junction (TPJ) was observed as a response to losing in participants with CP during the SELF-condition. Callous-unemotional (CU)-traits correlated negatively with activation of amygdala and right TPJ. During the OTHER-condition, TD participants showed activation in brain areas associated with theory of mind (right TPJ, left IFG), and affect regulation (right DLPFC) rather than areas associated with affective empathy. This pattern was not found in adolescents with CP. Moreover, and independently of individual characteristics of their opponents, adolescents with CP demonstrated reward-associated activation (ventral striatum) observing others win, which was positively correlated with CU-traits. This may be interpreted in line with the theory of reward dominance. Conclusions The current study provides support for the theory of abnormal learning processing in adolescents with CP which yields implications for further research as well as clinical practice. The gambling task did not activate affective empathy networks, but was specific for cognitive empathy, inhibition, and affect regulation. © 2016 Elsevier B.V
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
Increased volume and impaired function: the role of the basal ganglia in writer's cramp
Full text linkEINLEITUNG:
Der Schreibkrampf ist eine aufgabenspezifische fokale Dystonieform der Hand. Die genaue Ätiologie ist bisher noch unklar. Ziel unserer Studie war die Untersuchung des Basalganglienkreislauf und des Cerebellums während Durchführung einer komplexen, motorische Finger-Tipp-Aufgabe, welche mit der linken, gesunden Hand durchgeführt wurde und keine Dystonie auslöste.
METHODEN:
Wir führten strukturelle und funktionelle Messungen an 25 Schreibkrampfpatienten und 31 angepassten Kontrollpersonen mit Hilfe eines 3 Tesla MR-Scanner durch. Die funktionelle Bildgebung erfolgte während der Durchführung einer aus 5 Elementen bestehenden komplexen, sequentiellen Finger-Tipp-Aufgabe mit der linken, gesunden Hand so schnell und so fehlerfrei wie möglich. Die Aufgabe war in insgesamt 15 Blöcke aus je 30 Sekunden Tippen und 30 Sekunden Pause unterteilt. Für die strukturelle Auswertung wurde das Volumen an grauer Substanz mit der Methode der Voxel basierten Morphometrie (VBM) ermittelt.
ERGEBNISSE:
Während die Verhaltensdaten für beide Gruppen ein vergleichbares motorisches Lernverhalten zeigten, sahen wir im anterioren rechten Putamen und im linken Pallidum ein reduziertes blood oxygen level dependent- (BOLD-) Signal während Ausführung der sequentiellen Finger-Tipp-Aufgabe. Die VBM-Analyse zeigte ein signifikant erhöhtes Volumen an grauer Substanz im posteriorem Anteil des Putamen und Pallidum beidseits. Für das Cerebellum zeigten sich keine Gruppenunterschiede.
ZUSAMMENFASSUNG:
Unsere Ergebnisse stärken die Hypothese eines insuffizient funktionierenden Basalganglien-Kreislauf während der Generierung komplexer sequentieller Bewegungen mit der gesunden Hand. Das erhöhte Volumen an grauer Substanz in Putamen und Pallidum könnte hierbei sowohl einen Kompensationsmechanismus als auch eine primäre Prädispositiom darstellen. Unsere Ergebnisse sind in Einklang mit denen vorherigen Studien.INTRODUCTION:
The pathophysiology of writer's cramp, a task-specific dystonia, remains unclear. The objective of this study was to investigate the basal ganglia circuit and the cerebellum during a complex motor sequence learning task carried out with the nonaffected hand in writer's cramp patients.
METHODS:
We applied structural and functional imaging in 25 writer's cramp patients and 31 matched controls using 3T MRI. With the asymptomatic left hand all participants learned a complex, sequential, five-element sequence-tapping task as accurately and quickly as possible. Functional imaging was measured during a repeated (15 times), fixed block design with tapping (30 sec) and rest (30 sec). Additionally, gray matter volume of the basal ganglia was analyzed using voxel-based morphometry (VBM).
RESULTS:
While behavior was comparable between groups, after small volume correction the anterior part of the right putamen and the left globus pallidus exhibited reduced blood oxygen level-dependent (BOLD) activity in patients during the sequential finger-tapping task. VBM analysis showed larger gray matter volume bilateral in the posterior part of the putamen and globus pallidus. There were no group differences in the cerebellum.
CONCLUSION:
The results indicate an impairment of anterior basal ganglia loops involved in producing complex sequential movements of the unaffected hand. These findings are in line with previous reports of reduced neuronal activity in the globus pallidus internus. Higher gray matter volume of the putamen and globus pallidus may stem from elevated activity of the direct pathway, which could reflect a compensatory phenomenon or a primary predisposition, that is, endophenotypic trait
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