61 research outputs found

    Cerebral differences in explicit and implicit emotional processing - An fMRI study

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    The processing of emotional facial expression is a major part of social communication and understanding. In addition to explicit processing, facial expressions are also processed rapidly and automatically in the absence of explicit awareness. We investigated 12 healthy subjects by presenting them with an implicit and explicit emotional paradigm. The subjects reacted significantly faster in implicit than in explicit trials but did not differ in their error ratio. For the implicit condition increased signals were observed in particular in the thalami, the hippocampi, the frontal inferior gyri and the right middle temporal region. The analysis of the explicit condition showed increased blood-oxygen-level-dependent signals especially in the caudate nucleus, the cingulum and the right prefrontal cortex. The direct comparison of these 2 different processes revealed increased activity for explicit trials in the inferior, superior and middle frontal gyri, the middle cingulum and left parietal regions. Additional signal increases were detected in occipital regions, the cerebellum, and the right angular and lingual gyrus. Our data partially confirm the hypothesis of different neural substrates for the processing of implicit and explicit emotional stimuli. Copyright (c) 2007 S. Karger AG, Basel

    Neural processing of social rejection: the role of schizotypal personality traits

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    A fear of being rejected can cause perceptions of more insecurity and stress in close relationships. Healthy individuals activate the dorsal anterior cingulate cortex (dACC) when experiencing social rejection, while those who are vulnerable to depression deactivate the dACC presumably to downregulate salience of rejection cues and minimize distress. Schizotypal individuals, characterized by unusual perceptual experiences and/or odd beliefs, are more rejection sensitive than normal. We tested the hypothesis, for the first time, that individuals with high schizotypy also have an altered dACC response to rejection stimuli. Twenty-six healthy individuals, 14 with low schizotypy (LS) and 12 with high schizotypy (HS), viewed depictions of rejection and acceptance and neutral scenes while undergoing functional MRI. Activation maps in LS and HS groups during each image type were compared using SPM5, and their relation to participant mood and subjective ratings of the images was examined. During rejection relative to neutral scenes, LS activated and HS deactivated the bilateral dACC, right superior frontal gyrus, and left ventral prefrontal cortex. Across both groups, a temporo-occipito-parieto-cerebellar network was active during rejection, and a left fronto-parietal network during acceptance, relative to neutral scenes, and the bilateral lingual gyrus during rejection relative to acceptance scenes. Our finding of dACC-dorso-ventral PFC activation in LS, but deactivation in HS individuals when perceiving social rejection scenes suggests that HS individuals attach less salience to and distance themselves from such stimuli. This may enable them to cope with their higher-than-normal sensitivity to rejection

    Real-World Evidence: How Long Do Our Patients Fast?—Results from a Prospective JAGO-NOGGO-Multicenter Analysis on Perioperative Fasting in 924 Patients with Malignant and Benign Gynecological Diseases

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    Simple Summary: The concept of ERAS (Enhanced Recovery After Surgery) was introduced to reduce perioperative morbidity through a multimodal approach. Optimized and shortened perioperative fasting is a fundamental part of this modern concept of perioperative patient management, as prolonged fasting before and after surgery is associated with unfavorable outcomes. So far, it remains unclear whether increasingly established ERAS protocols lead to adequate short fasting intervals in clinical routines. We therefore conducted this prospective multicenter study and collected real-world data from 924 patients to evaluate actual perioperative fasting behavior. Patients reported drastically prolonged perioperative fasting durations. Even longer fasting intervals were reported for oncological and extensive procedures. Our data suggest that modern optimized fasting management is poorly implemented in clinical routine practice. This study should draw attention to the need for adequate implementation of ERAS protocols and sensitize clinicians to appropriate patient education about perioperative fasting. Background: Despite the key role of optimized fasting in modern perioperative patient management, little current data exist on perioperative fasting intervals in routine clinical practice. Methods: In this multicenter prospective study, the length of pre- and postoperative fasting intervals was assessed with the use of a specifically developed questionnaire. Between 15 January 2021 and 31 May 2022, 924 gynecology patients were included, from 13 German gynecology departments. Results: On average, patients remained fasting for about three times as long as recommended for solid foods (17:02 +/- 06:54 h) and about five times as long as recommended for clear fluids (9:21 +/- 5:48 h). The average perioperative fasting interval exceeded one day (28:23 +/- 14:02 h). Longer fasting intervals were observed before and after oncological or extensive procedures, while shorter preoperative fasting intervals were reported in the participating university hospitals. Smoking, treatment in a non-university hospital, an increased Charlson Comorbidity Index and extensive surgery were significant predictors of longer preoperative fasting from solid foods. In general, prolonged preoperative fasting was tolerated well and quality of patient information was perceived as good. Conclusion: Perioperative fasting intervals were drastically prolonged in this cohort of 924 gynecology patients. Our data indicate the need for better patient education about perioperative fasting

    Neural arbitration between social and individual learning systems

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    Decision making requires integrating self-gathered information with advice from others. However, the arbitration process by which one source of information is selected over the other has not been fully elucidated. In this study, we formalised arbitration as the relative precision of predictions, afforded by each learning system, using hierarchical Bayesian modelling. In a probabilistic learning task, participants predicted the outcome of a lottery using recommendations from a more informed advisor and/or self-sampled outcomes. Decision confidence, as measured by the number of points participants wagered on their predictions, varied with our relative precision definition of arbitration. Functional neuroimaging demonstrated arbitration signals that were independent of decision confidence and involved modality-specific brain regions. Arbitrating in favour of self-gathered information activated the dorsolateral prefrontal cortex and the midbrain, whereas arbitrating in favour of social information engaged the ventromedial prefrontal cortex and the amygdala. These findings indicate that relative precision captures arbitration between social and individual learning systems at both behavioural and neural levels

    Sex Differences in Neural Activation to Facial Expressions Denoting Contempt and Disgust

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    The facial expression of contempt has been regarded to communicate feelings of moral superiority. Contempt is an emotion that is closely related to disgust, but in contrast to disgust, contempt is inherently interpersonal and hierarchical. The aim of this study was twofold. First, to investigate the hypothesis of preferential amygdala responses to contempt expressions versus disgust. Second, to investigate whether, at a neural level, men would respond stronger to biological signals of interpersonal superiority (e.g., contempt) than women. We performed an experiment using functional magnetic resonance imaging (fMRI), in which participants watched facial expressions of contempt and disgust in addition to neutral expressions. The faces were presented as distractors in an oddball task in which participants had to react to one target face. Facial expressions of contempt and disgust activated a network of brain regions, including prefrontal areas (superior, middle and medial prefrontal gyrus), anterior cingulate, insula, amygdala, parietal cortex, fusiform gyrus, occipital cortex, putamen and thalamus. Contemptuous faces did not elicit stronger amygdala activation than did disgusted expressions. To limit the number of statistical comparisons, we confined our analyses of sex differences to the frontal and temporal lobes. Men displayed stronger brain activation than women to facial expressions of contempt in the medial frontal gyrus, inferior frontal gyrus, and superior temporal gyrus. Conversely, women showed stronger neural responses than men to facial expressions of disgust. In addition, the effect of stimulus sex differed for men versus women. Specifically, women showed stronger responses to male contemptuous faces (as compared to female expressions), in the insula and middle frontal gyrus. Contempt has been conceptualized as signaling perceived moral violations of social hierarchy, whereas disgust would signal violations of physical purity. Thus, our results suggest a neural basis for sex differences in moral sensitivity regarding hierarchy on the one hand and physical purity on the other

    Neural correlates of verbal working memory: an fMRI meta-analysis

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    Verbal Working memory (vWM) capacity measures the ability to maintain and manipulate verbal information for a short period of time. The specific neural correlates of this construct are still a matter of debate. The aim of this study was to conduct a coordinate-based meta-analysis of 42 fMRI studies on visual vWM in healthy subjects (n=795, males=459, females=325, unknown=11; age range: 18-75). The studies were obtained after an exhaustive literature search on PubMed, Scopus, Web of Science, and Brainmap database. We analyzed regional activation differences during fMRI tasks with the anisotropic effect-size version of seed-based d mapping software (ES-SDM). The results were further validated by performing jackknife sensitivity analyses and heterogeneity analyses. We investigated the effect of numerous relevant influencing factors by fitting corresponding linear regression models. We isolated consistent activation in a network containing fronto-parietal areas, right cerebellum, and basal ganglia structures. Regarding lateralization, the results pointed towards a bilateral frontal activation, a left-lateralization of parietal regions and a right-lateralization of the cerebellum, indicating that the left-hemisphere concept of vWM should be reconsidered. We also isolated activation in regions important for response inhibition, emphasizing the role of attentional control in vWM. Moreover, we found a significant influence of mean reaction time, load and age on activation associated with vWM. Activation in left medial frontal gyrus, left precentral gyrus and left precentral gyrus turned out to be positively associated with mean reaction time whereas load was associated with activation across the PFC, fusiform gyrus, parietal cortex and parts of the cerebellum. In the latter case activation was mainly detectable in both hemispheres whereas the influence of age became manifest predominantly in the left hemisphere. This led us to conclude that future vWM studies should take these factors into consideration

    Untersuchung der Grobreinigung von Kohlenmonoxid mit einem Wassergas-Shift-Reaktor im Reformatgas eines mit Biodiesel betriebenen Dampfreformers

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    Für APU-Anwendungen im Nutzfahrzeugbereich wird seit einiger Zeit der Einsatz von kompakten Reformer-Brennstoffzellensystem diskutiert. Erste kommerzielle Systeme sind bereits verfügbar. Prinzipiell können Reformer-Brennstoffzellen-Systeme auch mit Flüssigbrennstoffen wie Diesel und Biodiesel betrieben werden. Diese bieten den Vorteil einer bereits vorhandenen Infrastruktur und einer hohen Energiedichte. Im Rahmen der vorliegenden Arbeit wurde die CO-Entfernung im Reformatgas eines mit Biodiesel betriebenen Dampfreformers untersucht. Es konnte gezeigt werden, dass eine CO-Reduktion auf < 0,2 Vol.-% mit nur einer Wassergas-Shift-Stufe (WGS) möglich ist. Eine Kopplung des Biodiesel-Dampfreformers mit der HT-PEM ist damit ohne zusätzliche CO-Feinreinigung möglich
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