525 research outputs found

    Alexithymia modulates the experience of the rubber hand illusion

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    Alexithymia is associated with lower awareness of emotional and non-emotional internal bodily signals. However, evidence suggesting that alexithymia modulates body awareness at an external level is scarce. This study aimed to investigate whether alexithymia is associated with disrupted multisensory integration by using the rubber hand illusion task.Fifty healthy individuals completed the Toronto Alexithymia Scale and underwent the rubber hand illusion measure. In this measure, one watches a rubber hand being stroked synchronously or asynchronously with one’s own hand, which is hidden from view. Compared to the asynchronous stimulation, the synchronous stimulation results in the illusion that the rubber hand and the participant’s hand are closer together than they really are and that the rubber hand belongs to them. Results revealed that higher levels of alexithymia are associated with a lower ownership illusion. In conclusion, our findings demonstrate that high alexithymia scorers integrate two simultaneous sensory and proprioceptive events into a single experience (lower multisensory integration) to a lesser extent than low alexithymia scorers. Higher susceptibility to the illusion in high alexithymia scorers may -indicate that alexithymia is associated with impaired multisensory integration and that this association results from an abnormal focus of one's own body

    Atypical Self-Focus Effect on Interoceptive Accuracy in Anorexia Nervosa

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    Background: Interoceptive abilities are known to be affected in anorexia nervosa (AN). Previous studies could show that private self-focus can enhance interoceptive accuracy (IAcc) in healthy participants. As body dissatisfaction is high in AN, confrontation with bodily features such as the own face might have a directly opposed effect in AN. Whether patients with AN can benefit from self-focus in their IAcc and whether this pattern changes over the time-course of cognitive behavioral therapy was investigated in this study. Methods: 15 patients with AN from the Psychosomatic Clinic in Windach were assessed three times in the time course of a standardized cognitive-behavioral therapy. They were compared to 15 controls, recruited from Ulm University and tested in a comparable setting. Both groups performed the heartbeat perception task assessing interoceptive accuracy (IAcc) under two conditions either enhancing (Self) or decreasing (Other) self-focused attention. Furthermore, body dissatisfaction was assessed by a subscale of the Eating Disorder Inventory 2. Results: Patients with AN scored higher in IAcc when watching others’ faces as compared to one’s own face while performing the heartbeat perception task. The opposite pattern was observed in controls. IAcc remained reduced in AN as compared to controls in the time-course of cognitive-behavioral therapy, while body-dissatisfaction improved in AN. High body dissatisfaction was related to poorer IAcc in the Self condition. Conclusions: Our findings suggest that using self-focused attention reduces IAcc in AN while the opposite pattern was observed in controls. Confronting anorexic patients with bodily features might increase body-related avoidance and therefore decrease interoceptive accuracy. The current study introduces a new perspective concerning the role of interoceptive processes in AN and generates further questions regarding the therapeutic utility of methods targeting self-focus in the treatment of AN

    Optimal Data Placement on Networks With Constant Number of Clients

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    We introduce optimal algorithms for the problems of data placement (DP) and page placement (PP) in networks with a constant number of clients each of which has limited storage availability and issues requests for data objects. The objective for both problems is to efficiently utilize each client's storage (deciding where to place replicas of objects) so that the total incurred access and installation cost over all clients is minimized. In the PP problem an extra constraint on the maximum number of clients served by a single client must be satisfied. Our algorithms solve both problems optimally when all objects have uniform lengths. When objects lengths are non-uniform we also find the optimal solution, albeit a small, asymptotically tight violation of each client's storage size by Ï”\epsilonlmax where lmax is the maximum length of the objects and Ï”\epsilon some arbitrarily small positive constant. We make no assumption on the underlying topology of the network (metric, ultrametric etc.), thus obtaining the first non-trivial results for non-metric data placement problems

    Neuroimaging and psychophysiological investigation of the link between anxiety, enhanced affective reactivity and interoception in people with joint hypermobility

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    Objective: Anxiety is associated with increased physiological reactivity and also increased “interoceptive” sensitivity to such changes in internal bodily arousal. Joint hypermobility, an expression of a common variation in the connective tissue protein collagen, is increasingly recognized as a risk factor to anxiety and related disorders. This study explored the link between anxiety, interoceptive sensitivity and hypermobility in a sub-clinical population using neuroimaging and psychophysiological evaluation. Methods: Thirty-six healthy volunteers undertook interoceptive sensitivity tests, a clinical examination for hypermobility and completed validated questionnaire measures of state anxiety and body awareness tendency. Nineteen participants also performed an emotional processing paradigm during functional neuroimaging. Results: We confirmed a significant relationship between state anxiety score and joint hypermobility. Interoceptive sensitivity mediated the relationship between state anxiety and hypermobility. Hypermobile, compared to non-hypermobile, participants displayed heightened neural reactivity to sad and angry scenes within brain regions implicated in anxious feeling states, notably insular cortex. Conclusions: Our findings highlight the dependence of anxiety state on bodily context, and increase our understanding of the mechanisms through which vulnerability to anxiety disorders arises in people bearing a common variant of collagen

    KardiosensibilitÀt, Emotionen und kortikales Geschehen

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    In der vorgelegten Dissertation wird der Zusammenhang zwischen KardiosensibilitĂ€t, Emotionen und kortikalem Geschehen beleuchtet. HierfĂŒr wurden vier empirischen Studien durchgefĂŒhrt, die als ein Hauptanliegen solche zerebralen Strukturen identifizieren sollten, die sowohl an der Herzwahrnehmung als auch an der Entstehung des sog. Herzschlag-evozierten Potentials (HEP) beteiligt sind. Dabei wurde ausgehend von aktuellen Forschungsbefunden vermutet, dass es sich hierbei um viszerale Regulationsstrukturen wie die Insula, das anteriore Cingulum, den prĂ€frontalen Kortex und die somatosensorischen Kortizes handeln könnte. Des weiteren wurde postuliert, dass Unterschiede in der KardiosensibilitĂ€t sich sowohl in der Amplitude des HEP als auch in den Dipol-QuellstĂ€rken des HEP sowie in der AktivitĂ€t wĂ€hrend der Herzwahrnehmung nieder-schlagen. Die Ergebnisse der beiden HEP-Studien sowie der fMRT-Studie haben diese Hypothesen eindrucksvoll bestĂ€tigt. Über die verschiedenen Methoden hinweg (EEG, Dipolanalyse nach BESA, fMRT) wurde eine Aktivierung in den beschriebenen viszeralen Regulationsstrukturen gefunden, welche zudem mit der KardiosensibilitĂ€t positiv korrelierte. In der vierten Studie wurde das Zusammenspiel von Emotionen und KardiosensibilitĂ€t bei emotionaler BilderprĂ€sentation in einer EEG-Studie mit anschließender Stromdichterekon-struktion untersucht. Auch hierbei zeigte sich eine deutliche Modulation der visuell-evozierten Potentiale durch die KardiosensibilitĂ€t. Neben subjektiv berichteten höheren Arousal war die P300 und die Slow Wave in der Gruppe der guten Herzwahrnehmer erhöht. Die Stromdichterekonstruktion ergab wiederum positive Korrelationen zwischen der KardiosensibilitĂ€t und der AktivierungsstĂ€rke des anterioren Cingulums, des dorsolateralen Kortex, der Insula und der somatosensorischen Kortizes. Aufgrund der hier vorgelegten Ergebnisse wurden die genannten Strukturen als Koordinationszentren fĂŒr Emotionen und viszerale Regulation identifiziert, da die Areale ĂŒbereinstim-mend bei kardialer und emotionaler Aufgabenstellung eine Aktivierung aufwiesen sowie in gleichbleibender Weise durch die KardiosensibilitĂ€t modulierbar waren

    Complaints as starting point for vicious cycles in customer-employee-interactions

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    A ring-model of vicious cycles in customer employee-interaction is proposed: service employees perceive complaints as a threat to their self-esteem resulting in defense responses such as an increased need for cognitive closure, a devaluation of the customer and their information and degrading service behavior. Confronted with such degrading service behavior, customers react defensively as well, by devaluing the employee for example with regard to his/her competence and by reducing repurchase and positive word-of-mouth (WOM). Three studies investigated each link in this ringmodel. In study 1, participants were confronted with an aggressive or neutral customer complaint. Results show that motivated closed-mindedness (one aspect of the need for cognitive closure) increases after an aggressive complaint leading to a devaluation of the customer and their information, and in turn to a degrading service reaction. In study 2, participants were confronted with a degrading or favorable service reaction. Results show that they devaluate the employees' competence after receiving a degrading service reaction and thus reduce their intention to repurchase. In study 3, we finally examined our predictions investigating real customer employee-interactions: we analyzed data from an evaluation study in which mystery callers tested the service hotline of an airline. Results show that the employees' competence is devaluated after degrading behavior and thus reduces positive WOM

    Tree-based Focused Web Crawling with Reinforcement Learning

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    A focused crawler aims at discovering as many web pages relevant to a target topic as possible, while avoiding irrelevant ones. Reinforcement Learning (RL) has been utilized to optimize focused crawling. In this paper, we propose TRES, an RL-empowered framework for focused crawling. We model the crawling environment as a Markov Decision Process, which the RL agent aims at solving by determining a good crawling strategy. Starting from a few human provided keywords and a small text corpus, that are expected to be relevant to the target topic, TRES follows a keyword set expansion procedure, which guides crawling, and trains a classifier that constitutes the reward function. To avoid a computationally infeasible brute force method for selecting a best action, we propose Tree-Frontier, a decision-tree-based algorithm that adaptively discretizes the large state and action spaces and finds only a few representative actions. Tree-Frontier allows the agent to be likely to select near-optimal actions by being greedy over selecting the best representative action. Experimentally, we show that TRES significantly outperforms state-of-the-art methods in terms of harvest rate (ratio of relevant pages crawled), while Tree-Frontier reduces by orders of magnitude the number of actions needed to be evaluated at each timestep

    A cortical potential reflecting cardiac function

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    Emotional trauma and psychological stress can precipitate cardiac arrhythmia and sudden death through arrhythmogenic effects of efferent sympathetic drive. Patients with preexisting heart disease are particularly at risk. Moreover, generation of proarrhythmic activity patterns within cerebral autonomic centers may be amplified by afferent feedback from a dysfunctional myocardium. An electrocortical potential reflecting afferent cardiac information has been described, reflecting individual differences in interoceptive sensitivity (awareness of one's own heartbeats). To inform our understanding of mechanisms underlying arrhythmogenesis, we extended this approach, identifying electrocortical potentials corresponding to the cortical expression of afferent information about the integrity of myocardial function during stress. We measured changes in cardiac response simultaneously with electroencephalography in patients with established ventricular dysfunction. Experimentally induced mental stress enhanced cardiovascular indices of sympathetic activity (systolic blood pressure, heart rate, ventricular ejection fraction, and skin conductance) across all patients. However, the functional response of the myocardium varied; some patients increased, whereas others decreased, cardiac output during stress. Across patients, heartbeat-evoked potential amplitude at left temporal and lateral frontal electrode locations correlated with stress-induced changes in cardiac output, consistent with an afferent cortical representation of myocardial function during stress. Moreover, the amplitude of the heartbeat-evoked potential in the left temporal region reflected the proarrhythmic status of the heart (inhomogeneity of left ventricular repolarization). These observations delineate a cortical representation of cardiac function predictive of proarrhythmic abnormalities in cardiac repolarization. Our findings highlight the dynamic interaction of heart and brain in stress-induced cardiovascular morbidity

    Self-reported interoceptive deficits in eating disorders: A meta-analysis of studies using the eating disorder inventory

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    This document is the Accepted Manuscript version of the following article: Paul M. Jenkinson, Lauren Taylor, Keith R. Laws, ‘Self-reported interoceptive deficits in eating disorders: A meta-analysis of studies using the eating disorder inventory’, Journal of Psychosomatic Research, Vol. 110: 38-45, July 2018, under embargo until 19 April 2019. The Version of Record is available online at DOI: https://doi.org/10.1016/j.jpsychores.2018.04.005Objective: An impairment of the ability to sense the physiological condition of the body – interoception – has long been proposed as central to the onset and maintenance of eating disorders. More recent attention to this topic has generally indicated the presence of interoceptive deficits in individuals with an eating disorder diagnosis; however, possible links with specific diagnosis, BMI, age, illness duration, depression, and alexithymia remain unclear from individual studies. This meta-analysis aimed to provide a necessary quantitative overview of self-reported interoceptive deficits in eating disorder populations, and the relationship between these deficits and the previously mentioned factors. Methods: Using a random effects model, our meta-analysis assessed the magnitude of differences in interoceptive abilities as measured using the Eating Disorder Inventory in 41 samples comparing people with eating disorders (n=4308) and healthy controls (n=3459). Follow-up and moderator analysis was conducted, using group comparisons and meta-regressions. Results: We report a large pooled effect size of 1.62 for eating disorders with some variation between diagnostic groups. Further moderator analysis showed that BMI, age and alexithymia were significant predictors of overall effect size. Conclusion: This meta-analysis is the first to confirm that large interoceptive deficits occur in a variety of eating disorders and crucially, in those who have recovered. These deficits may be useful in identifying and distinguishing eating disorders. Future research needs to consider both objective and subjective measures of interoception across different types of eating disorders and may fruitfully examine interoception as a possible endophenotype and target for treatment.Peer reviewe

    From Driver to Supervisor: Comparing Cognitive Load and EEG-based Attentional Resource Allocation across Automation Levels

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    With increasing automation, drivers' roles transition from active operators to passive system supervisors, affecting their behaviour and cognitive processes. This study addresses the attentional resource allocation and subjective cognitive load during manual, SAE Level 2, and SAE Level 3 driving in a realistic environment. An experiment was conducted on a test track with 30 participants using a prototype automated vehicle. While driving, participants were subjected to a passive auditory oddball task and their electroencephalogram was recorded. The study analysed the amplitude of the P3a event-related potential component elicited by novel environmental stimuli, an objective measure of attentional resource allocation. The subjective cognitive load was assessed using the NASA Task Load Index. Results showed no significant difference in subjective cognitive load between manual and Level 2 driving, but a decrease in subjective cognitive load in Level 3 driving. The P3a amplitude was highest during manual driving, indicating increased attentional resource allocation to environmental sounds compared to Level 2 and Level 3 driving. This may suggest that during automated driving, drivers allocate fewer attentional resources to processing environmental information. It remains unclear whether the decreased processing of environmental stimuli in automated driving is due to top-down attention control (leading to attention withdrawal) or bottom-up competition for resources induced by cognitive load. This study provides novel empirical evidence on resource allocation and subjective cognitive load in automated driving. The findings highlight the importance of managing drivers' attention and cognitive load with implications for enhancing automation safety and the design of user interfaces.Comment: 17 pages, 4 figure
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