42 research outputs found

    Neuronal Generator Patterns At Scalp Elicited By Lateralized Aversive Pictures Reveal Consecutive Stages Of Motivated Attention

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    Event-related potential (ERP) studies have provided evidence for an allocation of attentional resources to enhance perceptual processing of motivationally salient stimuli. Emotional modulation affects several consecutive components associated with stages of affective-cognitive processing, beginning as early as 100–200 ms after stimulus onset. In agreement with the notion that the right parietotemporal region is critically involved during the perception of arousing affective stimuli, some ERP studies have reported asymmetric emotional ERP effects. However, it is difficult to separate emotional from non-emotional effects because differences in stimulus content unrelated to affective salience or task demands may also be associated with lateralized function or promote cognitive processing. Other concerns pertain to the operational definition and statistical independence of ERP component measures, their dependence on an EEG reference, and spatial smearing due to volume conduction, all of which impede the identification of distinct scalp activation patterns associated with affective processing. Building on prior research using a visual half-field paradigm with highly controlled emotional stimuli (pictures of cosmetic surgery patients showing disordered [negative] or healed [neutral] facial areas before or after treatment), 72channel ERPs recorded from 152 individuals (ages 13–68 years; 81 female) were transformed into reference-free current source density (CSD) waveforms and submitted to temporal principal components analysis (PCA) to identify their underlying neuronal generator patterns. Using both nonparametric randomization tests and repeated measures ANOVA, robust effects of emotional content were found over parietooccipital regions for CSD factors corresponding to N2 sink (212 ms peak latency), P3 source (385 ms) and a late centroparietal source (630 ms), all indicative of greater positivity for negative than neutral stimuli. For the N2 sink, emotional effects were right-lateralized and modulated by hemifield, with larger amplitude and asymmetry for left hemifield (right hemisphere) presentations. For all three factors, more positive amplitudes at parietooccipital sites were associated with increased ratings of negative valence and greater arousal. Distributed inverse solutions of the CSDPCA-based emotional effects implicated a sequence of maximal activations in right occipitotemporal cortex, bilateral posterior cingulate cortex, and bilateral inferior temporal cortex. These findings are consistent with hierarchical activations of the ventral visual pathway reflecting subsequent processing stages in response to motivationally salient stimuli

    Motivated Attention And Family Risk For Depression: Neuronal Generator Patterns At Scalp Elicited By Lateralized Aversive Pictures Reveal Blunted Emotional Responsivity

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    Behavioral and electrophysiologic evidence suggests that major depression (MDD) involves right parietotemporal dysfunction, a region activated by arousing affective stimuli. Building on prior event-related potential (ERP) findings (Kayser et al. 2016 NeuroImage 142:337–350), this study examined whether these abnormalities also characterize individuals at clinical high risk for MDD. We systematically explored the impact of family risk status and personal history of depression and anxiety on three distinct stages of emotional processing comprising the late positive potential (LPP). ERPs (72 channels) were recorded from 74 high and 53 low risk individuals (age 13–59 years, 58 male) during a visual half-field paradigm using highly-controlled pictures of cosmetic surgery patients showing disordered (negative) or healed (neutral) facial areas before or after treatment. Reference-free current source density (CSD) transformations of ERP waveforms were quantified by temporal principal components analysis (tPCA). Component scores of prominent CSD-tPCA factors sensitive to emotional content were analyzed via permutation tests and repeated measures ANOVA for mixed factorial designs with unstructured covariance matrix, including gender, age and clinical covariates. Factor-based distributed inverse solutions provided descriptive estimates of emotional brain activations at group level corresponding to hierarchical activations along ventral visual processing stream. Risk status affected emotional responsivity (increased positivity to negative-than-neutral stimuli) overlapping early N2 sink (peak latency 212 ms), P3 source (385 ms), and a late centroparietal source (630 ms). High risk individuals had reduced right-greater-thanleft emotional lateralization involving occipitotemporal cortex (N2 sink) and bilaterally reduced emotional effects involving posterior cingulate (P3 source) and inferior temporal cortex (630 ms) when compared to those at low risk. While the early emotional effects were enhanced for left hemifield (right hemisphere) presentations, hemifield modulations did not differ between risk groups, suggesting top-down rather than bottom-up effects of risk. Groups did not differ in their stimulus valence or arousal ratings. Similar effects were seen for individuals with a lifetime history of depression or anxiety disorder in comparison to those without. However, there was no evidence that risk status and history of MDD or anxiety disorder interacted in their impact on emotional responsivity, suggesting largely independent attenuation of attentional resource allocation to enhance perceptual processing of motivationally salient stimuli. These findings further suggest that a deficit in motivated attention preceding conscious awareness may be a marker of risk for depression

    Demonstrating test‐retest reliability of electrophysiological measures for healthy adults in a multisite study of biomarkers of antidepressant treatment response

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    Growing evidence suggests that loudness dependency of auditory evoked potentials (LDAEP) and resting EEG alpha and theta may be biological markers for predicting response to antidepressants. In spite of this promise, little is known about the joint reliability of these markers, and thus their clinical applicability. New standardized procedures were developed to improve the compatibility of data acquired with different EEG platforms, and used to examine test‐retest reliability for the three electrophysiological measures selected for a multisite project—Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care (EMBARC). Thirty‐nine healthy controls across four clinical research sites were tested in two sessions separated by about 1 week. Resting EEG (eyes‐open and eyes‐closed conditions) was recorded and LDAEP measured using binaural tones (1000 Hz, 40 ms) at five intensities (60–100 dB SPL). Principal components analysis of current source density waveforms reduced volume conduction and provided reference‐free measures of resting EEG alpha and N1 dipole activity to tones from auditory cortex. Low‐resolution electromagnetic tomography (LORETA) extracted resting theta current density measures corresponding to rostral anterior cingulate (rACC), which has been implicated in treatment response. There were no significant differences in posterior alpha, N1 dipole, or rACC theta across sessions. Test‐retest reliability was .84 for alpha, .87 for N1 dipole, and .70 for theta rACC current density. The demonstration of good‐to‐excellent reliability for these measures provides a template for future EEG/ERP studies from multiple testing sites, and an important step for evaluating them as biomarkers for predicting treatment response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135271/1/psyp12758_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135271/2/psyp12758.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135271/3/psyp12758-sup-0001-suppinfo1.pd

    The Critical Role of Notch Ligand Delta-like 1 in the Pathogenesis of Influenza A Virus (H1N1) Infection

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    Influenza A viral infections have been identified as the etiologic agents for historic pandemics, and contribute to the annual mortality associated with acute viral pneumonia. While both innate and acquired immunity are important in combating influenza virus infection, the mechanism connecting these arms of the immune system remains unknown. Recent data have indicated that the Notch system is an important bridge between antigen-presenting cells (APCs) and T cell communication circuits and plays a central role in driving the immune system to overcome disease. In the present study, we examine the role of Notch signaling during influenza H1N1 virus infection, focusing on APCs. We demonstrate here that macrophages, but not dendritic cells (DCs), increased Notch ligand Delta-like 1 (Dll1) expression following influenza virus challenge. Dll1 expression on macrophages was dependent on retinoic acid-inducible gene-I (RIG-I) induced type-I IFN pathway, and not on the TLR3-TRIF pathway. We also found that IFNα-Receptor knockout mice failed to induce Dll1 expression on lung macrophages and had enhanced mortality during influenza virus infection. Our results further showed that specific neutralization of Dll1 during influenza virus challenge induced higher mortality, impaired viral clearance, and decreased levels of IFN-γ. In addition, we blocked Notch signaling by using γ-secretase inhibitor (GSI), a Notch signaling inhibitor. Intranasal administration of GSI during influenza infection also led to higher mortality, and higher virus load with excessive inflammation and an impaired production of IFN-γ in lungs. Moreover, Dll1 expression on macrophages specifically regulates IFN-γ levels from CD4+and CD8+T cells, which are important for anti-viral immunity. Together, the results of this study show that Dll1 positively influences the development of anti-viral immunity, and may provide mechanistic approaches for modifying and controlling the immune response against influenza H1N1 virus infection

    WHERE DOES THE ART LIVE / A look at architecture, art and urban space: Circle of Plastic Arts of Coimbra | The Mermaid Garden and São Paulo Museum of Modern Art | Ibirapuera Park.

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    Relatório de Estágio do Mestrado em Estudos Curatoriais apresentado ao Colégio das ArtesRESUMO LÁRIOS, Karen Emmerich D’Arc Bruder. ONDE MORA A ARTE. Um olhar sobre a arquitetura, a arte e o espaço urbano: Círculo de Artes Plásticas de Coimbra | Jardim da Sereia e Museu de Arte Moderna de São Paulo | Parque Ibirapuera. 2017. Dissertação de Mestrado em Estudos Curatoriais, Colégio das Artes da Universidade de Coimbra, Coimbra. A abordagem central deste trabalho é a arquitetura com um olhar pela arte. A dissertação promove uma reflexão sobre o edifício expositivo contemporâneo e as tipologias museológicas herdadas; e analisa as relações interdisciplinares do complexo «arte-arquitetura-cidade», assinalando a valoração dos parques verdes envolventes nessa convivência. Através de dois casos-de-estudo, o Círculo de Artes Plásticas de Coimbra no Jardim da Sereia e o Museu de Arte Moderna de São Paulo no Parque Ibirapuera, a dissertação expõe os contextos históricos-culturais; analisa a ocupação da arquitetura concebida para função diversa e a adaptação espacial ao novo uso como centro de arte contemporânea; e reflete sobre as relações interdisciplinares entre a arquitetura, a arte contemporânea e os espaços verdes envolventes, sinalizando as articulações entre o interno e o externo e entre o público e o privado. Nessa demonstração, a dissertação manifesta-se sobre a arte, a arquitetura e a cultura a partir de uma análise das instalações, histórias e coleções, reafirmando a identidade e a vocação cultural do CAPC Sereia em Portugal e do MAM Ibirapuera no Brasil.Em síntese, o presente trabalho impulsiona uma reflexão sobre o fomento e a valorização do intercâmbio cultural entre a arquitetura, a arte e o contexto urbano.ABSTRACT LÁRIOS, Karen Emmerich D’Arc Bruder. WHERE DOES THE ART LIVE / A look at architecture, art and urban space: Circle of Plastic Arts of Coimbra | The Mermaid Garden and São Paulo Museum of Modern Art | Ibirapuera Park. 2017. Master’s thesis in Curatorial Studies, College of Arts at Coimbra University, Coimbra.The central approach of this study is architecture with an eye for art. The thesis promotes a reflection on the contemporary expository building and the inherited museological typologies; and analyzes the interdisciplinary relations of the complex «art-architecture-city», indicating the valuation of the surrounding green parks in this coexistence.Through two case studies, the Circle of Plastic Arts of Coimbra at The Mermaid Garden and São Paulo Museum of Modern Art at Ibirapuera Park, the thesis exposes the historical-cultural context; analyzes the occupation of the architecture designed for a diverse function and its spatial adaptation to its new use as a center of contemporary art; and reflects on the interdisciplinary relations between architecture, contemporary art and the green areas surrounding it, evidencing the links between internal and external and between public and private.In this demonstration, the thesis reveals art, architecture and culture from an analysis of the installations, stories and collections, reaffirming the identity and the cultural vocation of Circle of Plastic Arts of Coimbra at The Mermaid Garden, Portugal and São Paulo Museum of Modern Art at Ibirapuera Park, Brazil.In short, the present study promotes a reflection on the encouragement and appreciation of the cultural exchange between architecture, art and the urban context
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