1,721,172 research outputs found
From lab to daily life: determining the acute neurochemical effects of intrusive thinking in pathological and non-pathological worriers
No full textBackground: Intrusive thinking (IT) is a transdiagnostic psychiatric symptom that causes clinically significant distress and impairments in important areas of functioning. Alterations in glutamate and GABA metabolism are posited to be implicated in the pathophysiology of many neuropsychiatric disorders, such as depression and generalized anxiety disorder[1,2]. However, in humans, levels of such metabolites are quantified ex vivo or in circulating plasma. Moreover, comparisons between pathological and healthy individuals are primarily at rest[3] and not during specific disease states, making it difficult to understand the psychobiological processes underpinning IT.
The present study had two Aims: i) investigating the acute effects of an experimental induction of IT on levels of glutamate and GABA in pathological and non-pathological worriers; ii) testing daily-life validity of the results by ecological momentary assessment (EMA) of IT on the same participants.
Methods: 3T-proton magnetic resonance spectroscopy (MRS) was applied in the bilateral Anterior Cingulate Cortex (ACC) and regional levels of Glx (Glutamate+Glutamine) and GABA were in vivo quantified before and after a well-replicated experimental induction of IT[4]. ACC was selected since it regulates the central autonomic network and it is involved in the clinical maintenance of IT[5]. After completed a psychiatric and clinical screening, both pathological (n = 16; 7 males) and control individuals (n = 17; 8 males) were asked to recall and describe an episode/image that had been recently intruding in their mind over and over without them wanting this to happen. Visual analog scales were administered at four time points to assess manipulation effects on self-reported momentary mood and levels of thoughts intrusiveness, repetitiveness and stuckness. Heart rate and respiration were recorded throughout MRS sessions to assess the physiological concomitants of IT[4]. Laboratory session was followed-up by a two-day EMA aimed at measuring daily-life emergence of IT. Repeated measures ANOVA and random effect regression models were used as methods of analysis.
Results: The two groups did not differ in any of the examined socio-demographic and baseline variables. The induction strongly engendered levels of thoughts intrusiveness, repetitiveness and stuckness in both groups. Results showed a trend toward an increase in regional levels of GABA from pre- to post-induction in both pathological and healthy individuals, though they were not statistically significant. Notably, an opposite pattern emerged for Glx where a statistically significant Time x Goup interaction emerged (for Glx/Water: p = .04, ηp2= .18; for Glx/Cre: p=.03, ηp2= .17), with a pre- to post-induction increase in controls (ps < .05) and a decrease in pathological worriers (ps < .05). Resting levels of GABA and Glx in ACC predicted subjective responses to the induction (ps < .05) as well as daily life levels of thoughts intrusiveness and repetitiveness (ps < .05).
Conclusion: Current findings suggest that dysfunctions in glutamatergic neurometabolism within ACC may contribute to the maintenance of IT in pathological individuals, and they are in line with a dimensional view of psychopathology, showing that IT has the effect of making healthy individuals neurally-like disordered ones. If replicated, present results may inform personally-tailored treatments in the framework of precision psychiatry.
References
[1] Brambilla P, Perez J, Barale F, Schettini G, Soares JC. GABAergic dysfunction in mood disorders. Mol Psychiatry. 2003;8(8):721-737. [2] Lener MS, Niciu MJ, Ballard ED, et al. Glutamate and Gamma-Aminobutyric Acid Systems in the Pathophysiology of Major Depression and Antidepressant Response to Ketamine. Biological Psychiatry. 2017;81(10):886-897. [3] Moriguchi S, Takamiya A, Noda Y, et al. Glutamatergic neurometabolite levels in major depressive disorder: a systematic review and meta-analysis of proton magnetic resonance spectroscopy studies. Mol Psychiatry. 2019;24(7):952-964. [4] Ottaviani C, Thayer JF, Verkuil B, et al. Physiological concomitants of perseverative cognition: A systematic review and meta-analysis. Psychological Bulletin. 2016;2016;142(3):231-25959. [5] Makovac E, Fagioli S, Rae CL, Critchley HD, Ottaviani C. Can’t get it off my brain: Meta-analysis of neuroimaging studies on perseverative cognition. Psychiatry Research: Neuroimaging. 2020;295:111020
Face your heart: resting vagally mediated Heart Rate Variability Shapes Social Attributions from facial appearance
No full textPhylogenetic theories suggest resting vagally mediated heart rate variability (vmHRV) as a biomarker for adaptive behavior in social encounters. Until now, no study has examined whether vmHRV can predict individual differences in inferring personality traits and intentions from facial appearance. To test this hypothesis, resting vmHRV was recorded in 83 healthy individuals before they rated a series of faces based on their first impression of trustworthiness, dominance, typicality, familiarity, caring, and attractiveness. We found an association between individual differences in vmHRV and social attributions from facial appearance. Specifically, higher levels of vmHRV predicted higher scores on ratings of caring and trustworthiness, suggesting that strangers’ faces are more likely to be perceived as safer. The present results suggest that higher levels of vmHRV (compared with lower levels of vmHRV) are associated with the tendency to minimize social evaluative threat and maximize affiliative social cues at a first glance of others’ faces
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
Trusting your heart: long-term memory for bad and good people is influenced by resting vagal tone
No full textSeveral studies have highlighted the role of heart rate variability (HRV) in social engagement and social cognition. However, whether HRV is involved in the ability to remember faces associated with affectively salient behavioural information remains unexplored. The present study aims to close this gap by investigating long-term face-memory accuracy in individuals differing in resting vagally-mediated HRV. Individuals with high or low resting HRV viewed faces associated with episodic information differing in affective valence (positive, neutral, negative) or without any behavioural description. After one week, a face recognition test was administered. High HRV individuals were better at recognizing faces paired with positive and negative behavioural descriptions compared to neutral faces or faces without descriptions. Conversely, low HRV participants did not show any face memory advantage from personal information. The present results suggest that HRV may provide a novel biological marker of long-term face recognition
Lumbricus terrestris as a simplified animal model to approach the study of the intrinsic contractility of vertebrate lymphatic vessels: a pilot study
No full textDispelling 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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