580 research outputs found

    Thrombotische Mikroangiopathien nach extrakorporaler Zirkulation: Wichtige Differenzialdiagnose

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    Zusammenfassung: Thrombotische Mikroangiopathien sind durch Thrombozytenaktivierung, Endothelzellschädigung, Hämolyse und mikrovaskuläre Okklusionen gekennzeichnet. Es handelt sich hierbei um eine Gruppe von Erkrankungen, deren Hauptvertreter die thrombotische thrombozytopenische Purpura (TTP) und das hämolytisch-urämische Syndrom (HUS) sind. Klinisch bestehen bei den Patienten eine mikroangiopathische hämolytische Anämie mit Thrombozytopenie und okklusionsbedingte Organischämien in variabler Ausprägung. Die Symptomatik der einzelnen Krankheitsbilder überschneidet sich häufig, sodass eine eindeutige Zuordnung anhand klinischer Kriterien oft schwierig ist. Aufgrund einer hohen Mortalität, insbesondere der TTP, sind eine schnelle Diagnostik und Therapie erforderlich. Es wird über 2Patienten mit thrombotischen Mikroangiopathien nach kardiochirurgischen Eingriffen berichtet. Da TTP, HUS und eine medikamentöse Ätiologie weitgehend ausgeschlossen wurden, wurde ein Zusammenhang zwischen der extrakorporalen Zirkulation während dem herzchirurgischen Eingriff und der thrombotischen Mikroangiopathie vermute

    Art reception as an interoceptive embodied predictive experience

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    In the Distancing-Embracing model, an explanation is proposed for the apparent paradox that is the enjoyment of negative emotional states in art reception. Here, we argue for the advantages of grounding the psychological dynamics described in the model in established and empirically testable frameworks of brain functioning by thinking of art reception as an embodied experience guided by predictive coding

    Owning an overweight or underweight body: distinguishing the physical, experienced and virtual body

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    Our bodies are the most intimately familiar objects we encounter in our perceptual environment. Virtual reality provides a unique method to allow us to experience having a very different body from our own, thereby providing a valuable method to explore the plasticity of body representation. In this paper, we show that women can experience ownership over a whole virtual body that is considerably smaller or larger than their physical body. In order to gain a better understanding of the mechanisms underlying body ownership, we use an embodiment questionnaire, and introduce two new behavioral response measures: an affordance estimation task (indirect measure of body size) and a body size estimation task (direct measure of body size). Interestingly, after viewing the virtual body from first person perspective, both the affordance and the body size estimation tasks indicate a change in the perception of the size of the participant’s experienced body. The change is biased by the size of the virtual body (overweight or underweight). Another novel aspect of our study is that we distinguish between the physical, experienced and virtual bodies, by asking participants to provide affordance and body size estimations for each of the three bodies separately. This methodological point is important for virtual reality experiments investigating body ownership of a virtual body, because it offers a better understanding of which cues (e.g. visual, proprioceptive, memory, or a combination thereof) influence body perception, and whether the impact of these cues can vary between different setups

    Dynamics of Nanometer-Scale Foil Targets Irradiated with Relativistically Intense Laser Pulses

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    In this letter we report on an experimental study of high harmonic radiation generated in nanometer-scale foil targets irradiated under normal incidence. The experiments constitute the first unambiguous observation of odd-numbered relativistic harmonics generated by the v×B\vec{v}\times\vec{B} component of the Lorentz force verifying a long predicted property of solid target harmonics. Simultaneously the observed harmonic spectra allow in-situ extraction of the target density in an experimental scenario which is of utmost interest for applications such as ion acceleration by the radiation pressure of an ultraintense laser.Comment: 5 pages, 4 figure

    From the viscera to first impressions: Phase dependent cardio-visual signals bias the perceived trustworthiness of faces

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    When we see new people, we rapidly form first impressions. Whereas past research has focused on the role of morphological or emotional cues, we asked whether transient visceral states bias the impressions we form. Across three studies (N = 94 university students), we investigated how fluctuations of bodily states, driven by the interoceptive impact of cardiac signals, influence the perceived trustworthiness of faces. Participants less often chose faces presented in synchrony with their own cardiac systole as more trustworthy than faces presented out of synchrony. Participants also explicitly judged faces presented in synchrony with their cardiac systole as less trustworthy. Finally, the presentation of faces in synchrony with participants’ cardiac diastole did not modulate participants’ perceptions of the faces’ trustworthiness, suggesting that the systolic phase is necessary for such interoceptive effects. These findings highlight the role of phasic interoceptive information in the processing of social information and provide a mechanistic account of the role of visceroception for social perception

    Emotion matters: Different psychophysiological responses to expressive and non-expressive full-body movements

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    We explore dance video clip stimuli as a means to test human observers' accuracy in detecting genuine emotional expressivity in full-body movements. Stimuli of every-day-type full-body expressions of emotions usually use culturally very recognizable actions (e.g. fist shaking for anger, etc). However, expressive dance movement stimuli can be created to contain fully abstract movements. The expressivity results from subtle variations in the body movements of the expressor, and emotions cannot be recognised by observers via particular actions (e.g. fist shaking, etc). Forty-one participants watched and rated 24 pairs of short dance videos –from a published normalised dance stimuli library– in randomised order (N = 48). Of each carefully matched pair, one version of the full-body movement sequence had been danced to be emotionally genuinely expressive (clip a), while the other version of the same sequence (clip b) had been danced –while technically correct– without any emotional expressivity. Participants rated (i) expressivity (to test their accuracy; block 1), and (ii) how much they liked each movement (an implicit measure to test their emotional response (“liking”); block 2). Participants rated clips that were intended to be expressive as more expressive (part 1: expressivity ratings), and liked those expressive clips more than the non-expressive clips (part 2: liking ratings). Besides, their galvanic skin response differed, depending on the category of clips they were watching (expressive vs. non-expressive), and this relationship was modulated by interceptive accuracy and arts experience. Results are discussed in relation to the Body Precision Hypothesis and the Hypothesis of Constructed Emotion

    The Human Touch: Skin Temperature During the Rubber Hand Illusion in Manual and Automated Stroking Procedures

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    Rohde M, Wold A, Karnath H-O, Ernst MO. The Human Touch: Skin Temperature During the Rubber Hand Illusion in Manual and Automated Stroking Procedures. PLoS ONE. 2013;8(11): e80688.A difference in skin temperature between the hands has been identified as a physiological correlate of the rubber hand illusion (RHI). The RHI is an illusion of body ownership, where participants perceive body ownership over a rubber hand if they see it being stroked in synchrony with their own occluded hand. The current study set out to replicate this result, i.e., psychologically induced cooling of the stimulated hand using an automated stroking paradigm, where stimulation was delivered by a robot arm (PHANToMTM force-feedback device). After we found no evidence for hand cooling in two experiments using this automated procedure, we reverted to a manual stroking paradigm, which is closer to the one employed in the study that first produced this effect. With this procedure, we observed a relative cooling of the stimulated hand in both the experimental and the control condition. The subjective experience of ownership, as rated by the participants, by contrast, was strictly linked to synchronous stroking in all three experiments. This implies that hand-cooling is not a strict correlate of the subjective feeling of hand ownership in the RHI. Factors associated with the differences between the two designs (differences in pressure of tactile stimulation, presence of another person) that were thus far considered irrelevant to the RHI appear to play a role in bringing about this temperature effect

    Measuring the effects through time of the influence of visuomotor and visuotactile synchronous stimulation on a virtual body ownership illusion

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    Previous studies have examined the experience of owning a virtual surrogate body or body part through specific combinations of cross-modal multisensory stimulation. Both visuomotor (VM) and visuotactile (VT) synchronous stimulation have been shown to be important for inducing a body ownership illusion, each tested separately or both in combination. In this study we compared the relative importance of these two cross-modal correlations, when both are provided in the same immersive virtual reality setup and the same experiment. We systematically manipulated VT and VM contingencies in order to assess their relative role and mutual interaction. Moreover, we present a new method for measuring the induced body ownership illusion through time, by recording reports of breaks in the illusion of ownership ("breaks") throughout the experimental phase. The balance of the evidence, from both questionnaires and analysis of the breaks, suggests that while VM synchronous stimulation contributes the greatest to the attainment of the illusion, a disruption of either (through asynchronous stimulation) contributes equally to the probability of a break in the illusion

    Self-Motion Holds a Special Status in Visual Processing

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    Agency plays an important role in self-recognition from motion. Here, we investigated whether our own movements benefit from preferential processing even when the task is unrelated to self-recognition, and does not involve agency judgments. Participants searched for a moving target defined by its known shape among moving distractors, while continuously moving the computer mouse with one hand. They thereby controlled the motion of one item, which was randomly either the target or any of the distractors, while the other items followed pre-recorded motion pathways. Performance was more accurate and less prone to degradation as set size increased when the target was the self-controlled item. An additional experiment confirmed that participant-controlled motion was not physically more salient than motion recorded offline. We found no evidence that self-controlled items captured attention. Taken together, these results suggest that visual events are perceived more accurately when they are the consequences of our actions, even when self-motion is task irrelevant

    Seeing myself through my heart: Cortical processing of a single heartbeat speeds up self-face recognition

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    Recent research has highlighted the contribution of interoceptive signals to different aspects of bodily self-consciousness (BSC) by means of the cardio-visual stimulation - i.e. perceiving a pulsing stimulus in synchrony with one’s own heart. Here, for the first time, we investigate the effects of individual heartbeats on a critical feature of BSC, namely the recognition of one’s own face. Across two studies, we explored the cardiac-timing effects on a classic self-face recognition task. In Study 1, participants saw morphed faces that contained different percentages of the self-face and that of another unfamiliar individual. Study 2 used a similar design, albeit participants saw morphed faces of the self-face and that of a familiar other to provide a better control of self-familiarity. Results from both studies consistently revealed that the cortical processing of cardiac afferent signals conveyed by the firing of arterial baroreceptors affects the speed, but not the accuracy, of self-face recognition, when a single picture is presented during cardiac systole, as compared to diastole. This effect is stronger and more stable for stimuli with more self-cues than other-cues and for ‘ambiguous’ stimuli – i.e. at the individual point of subjective equality. Results from Study 2 also revealed that cardiac effects on the speed of self-face recognition cannot be explained simply on the basis of the imbalanced familiarity between the self’s and other’s faces used. The present findings highlight the interoceptive contributions to self-recognition and may be expand our understanding of pathological disturbances of self-experience
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