1,720,964 research outputs found
5-HT7 receptors in the modulation of cognitive processes
No full textThe abundance of serotonin (5-HT) in the central nervous system can explain its role in the regulation of various functions, such as sleep, feeding,sexuality, emotional status, and pain. In addition, 5-HT localized in “cognitive pathways” with hippocampus and frontal cortex as the main target
structures, is involved in learning and memory processes. Recent studies led to the discovery of various types and subtypes of receptors, differentially
associated to cognitive mechanisms. Abundant data available reveals that the administration of 5-HT2A/2C and 5-HT4 receptor agonists, or 5-HT1A,5-HT3 and 5-HT1B antagonists improves memory and has a facilitatory effect on learning in situations involving a high cognitive demand. On the contrary 5-HT2A/2C and 5-HT4 receptors antagonists, or 5-HT1A, 5-HT3 and 5-HT1B receptors agonists have opposite effects. Although these results
are contradictory, or even opposite, it is important to take into account the effect of global, and unspecific, stimulation of serotonergic receptors and the activation of other neurotransmission systems, together with the type of task used, the way it is administered and the ligand affinity.
The aim of this review is to clarify the behavioral role of the recently discovered 5-HT7-type receptor and highlight its involvement in the modulation of learning and memory processes, thus providing a basis to obtain new therapeutic agents and strategies for the treatment of learning and memory disorders
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
Working memory for emotional facial expressions: role of the estrogen in young women
No full textPhysiological hormonal fluctuations during the menstrual cycle, postpartum, and menopause have been implicated in the modulation of mood, cognition, and affective disorders.
Taking into account that women’s performance in memory tasks can also fluctuate with
circulating hormones levels across the menstrual cycle, the cognitive performance in a working memory task for emotional facial expressions, using the six basic emotions as stimuli in the delayed matching-to-sample, was evaluated in young women in different phases of the menstrual cycle. Our findings suggest that high levels of estradiol in the follicular phase could have a negative effect on delayed matching-to-sample working memory task, using stimuli with emotional
valence. Moreover, in the follicular phase, compared to the menstrual phase, the percent of errors was significantly higher for the emotional facial expressions of sadness and disgust. The
evaluation of the response times (time employed to answer) for each facial expression with emotional valence showed a significant difference between follicular and luteal in reference to
the emotional facial expression of sadness. Our results show that high levels of estradiol in the follicular phase coul impair the performance of working memory. However, this effect is specific to selective facial expressions suggesting that, across the phases of the menstrual cycle, in which
conception risk is high, women could give less importance to the recognition of the emotional facial expressions of sadness and disgust. This study is in agreement with research conducted on non-human primates, showing that fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors. Moreover, our data could also represent a
useful tool for investigating emotional disturbances linked to menstrual cycle phases and
menopause in women
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
Explict Memory and Emotional Stimuli: An Event Related Potential Study
No full textGender-related lateralized effect of emotion on memory was evaluated through neutral/emotional stimuli and ERPs. We compared left/right hemisphere P300 at P3/P4 in response to emotional/neutral stimuli in men/women. Opposite to right hemisphere, in left hemisphere emotional story elicited stronger P300 in women. Sex/hemisphere constitute relevant, interacting influences on emotional memor
Emotional memory and migraine: Effects of amytriptyline and sex related difference
No full textMany studies suggest that emotional arousal improves memory storage. The aim of this study was to evaluate the effects of emotional content on explicit memory in untreated cephalalgic patients and in migraineurs treated with the antidepressant amitriptyline. We utilized an adaptation
of two versions of the same story, with different arousing properties (neutral or emotional), which have been already employed in experiments involving the enhancing effects of emotions on memory retention.
Subjects of the present study were healthy subjects and cephalalgic patients, suffering from migraine headache, which included untreated migraineurs and migraineurs treated with the antidepressant amitriptyline. The findings of our experiments suggest that chronic migraine is related
to memory impairment. Taking into account that migraine is associated with major depression, in the present research the effect of the antidepressant
amitriptyline was also evaluated. Our results showed that amitriptyline has an impairment effect on memory. In fact, the untreated migraineurs,compared to treated, recalled the most emotional phase of the arousal story significantly better. Then, our data suggest that amitriptyline prevents the enhancing effects of emotional content on memory processes. Moreover, in agreement with our previous data, this study suggests the existence
of gender differences in the processing of emotional stimuli and underscores the importance of sex on emotional memory mechanisms
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
- …
