Search results for "SYSTEMS"
showing 10 items of 11952 documents
Interaction of hyperalgesia and sensory loss in complex regional pain syndrome type I (CRPS I).
2008
Background: Sensory abnormalities are a key feature of Complex Regional Pain Syndrome (CRPS). In order to characterise these changes in patients suffering from acute or chronic CRPS I, we used Quantitative Sensory Testing (QST) in comparison to an age and gender matched control group. Methods: 61 patients presenting with CRPS I of the upper extremity and 56 healthy subjects were prospectively assessed using QST. The patients’ warm and cold detection thresholds (WDT; CDT), the heat and cold pain thresholds (HPT; CPT) and the occurrence of paradoxical heat sensation (PHS) were observed. Results: In acute CRPS I, patients showed warm and cold hyperalgesia, indicated by significant changes in H…
The effects of light exposure on the cortisol stress response in human males.
2020
It is assumed that the production of cortisol is modulated by light exposure. While initial evidence supports this principal effect, the specific effect of light (intensity and wavelength) onto the cortisol stress response is still not completely understood. One between-subject experiment was conducted in a standardized sleep laboratory setting to investigate the effect of light intensity (dim white vs. bright white light) and spectral composition (red vs. blue) on the cortisol response after the Maastricht Acute Stress Test (MAST). 112 healthy young males (24.83 ± 4.10 years of age) were randomly assigned to one of the four light conditions. Across conditions, light exposure was conducted …
Assessing the antecedents and consequences of threat appraisal of an acute psychosocial stressor: the role of optimism, displacement behavior, and ph…
2018
The feeling of stress is increasing in today's societies, particularly in young adults subjected to social evaluative situations in highly competitive academic and work contexts. Threat appraisal is a primary and fundamental reaction when people face a stressful situation. The aim of this study was to investigate the role of dispositional optimism as an antecedent and displacement behavior as a consequence of threat appraisal of a social-evaluative situation of stress. A second objective was to verify the moderating role of physiological responses to stress (heart rate and cortisol reactivity) in the relationship between threat appraisal and displacement behavior. To do this, we combined th…
Blood endocannabinoid levels in patients with panic disorder.
2020
Abstract Background The development and maintenance of anxiety disorders is not fully understood. There is consensus in the literature that in addition to genetic factors, social, psychological and neurobiological factors are of crucial importance. The present exploratory study investigates the influence of the endocannabinoids (EC) and related N-acylethanolamines (NA) on the maintenance of panic disorder (PD). Methods A total of n = 36 PD and n = 26 healthy controls (HC) were included in the study. Baseline characteristics showed no differences between the two groups. The participants were exposed to the Trier Social Stress Test (TSST) for reliable laboratory stress induction. Blood sample…
Weekly monitoring of dexamethasone suppression response in depression: its relationship to change of body weight and psychopathology
1985
Abstract Weekly dexamethasone suppression tests (DST) were performed in 19 hospitalized patients with major depressive disorder, endogenous subtype, and who had an abnormal DST at admission. Depression scores (Hamilton Rating Scale) and weight changes were collected by investigators who were blind to the test results. Major findings were: (1) the DST gradually normalized 3–4 weeks prior to full resolution of clinical symptomatology; (2) weight loss was an important patient variable which may have contributed to false positive DST results; however, the positive correlation between changes in DST results and changes in depression scores in all our patients with or without weight loss suggests…
Stress-induced pro- and anti-inflammatory cytokine concentrations in panic disorder patients
2018
Abstract Background An attenuated responsivity of the hypothalamus–hypophysis-adrenal (HPA) axis upon challenge and an increased risk for cardiac events are relatively consistent findings in panic disorder (PD) patients. Due to cytokine-HPA interactions, an altered HPA-axis responsivity may be accompanied by altered cytokine concentrations. Immunological reactions under stress might be considered the missing link for explaining an increased cardiac risk. This study analyzed stress-induced cytokine levels in PD patients. Methods A total of n = 32 PD patients and n = 32 healthy control individuals performed the Trier Social Test (TSST). Blood sample collection accompanied the TSST for the col…
Configural information in gender categorisation.
2006
International audience; The role of configural information in gender categorisation was Studied by aligning the top half of one face with the bottom half of another. The two faces had the same or different genders. Experiment I shows that participants were slower and made more errors in categorising the gender in either half of these composite faces when the two faces had a different gender, relative to control conditions where the two faces were nonaligned or had the same gender. This result parallels the composite effect for face recognition (Young et al. 1987 Perception 16 747 - 759) and facial-expression recognition (Calder et al. 2000 Journal of Experimental Psychology: Human Perceptio…
Epoch versus impulse models in the analysis of parametric fMRI studies
2013
Abstract Objective In parametric fMRI studies the relationship between the amplitude of the hemodynamic response and electrophysiological or behavioral parameters is commonly analyzed using the general linear model (GLM). We examined ways of using single-trial response time (RT) in the analysis of a decision-making task to better isolate task-specific activation. Methods fMRI and RT data were recorded in twenty-one subjects performing a visual-oddball-task. Four explanatory variables (EVs) were generated for the GLM-analysis: A conventional (constant impulse) EV, a constant epoch EV informed using subjects’ average RT, a variable impulse EV and a variable epoch EV both informed using single…
Lag-specific transfer entropy as a tool to assess cardiovascular and cardiorespiratory information transfer
2014
In the study of interacting physiological systems, model-free tools for time series analysis are fundamental to provide a proper description of how the coupling among systems arises from the multiple involved regulatory mechanisms. This study presents an approach which evaluates direction, magnitude, and exact timing of the information transfer between two time series belonging to a multivariate dataset. The approach performs a decomposition of the well-known transfer entropy (TE) which achieves 1) identifying, according to a lag-specific information-theoretic formulation of the concept of Granger causality, the set of time lags associated with significant information transfer, and 2) assig…
Intracortical inhibition and facilitation in human facial motor area: difference between upper and lower facial area.
2001
Objective: To investigate the intracortical inhibitory and excitatory systems in the motor cortical representation of upper and lower facial muscles. Methods: Paired-pulse transcranial magnetic stimulation (TMS) was applied to 7 healthy volunteers, with the interstimulus interval (ISI) between the conditioning stimulus (CS) and test stimulus, varied from 1 to 20 ms. CS was set at 90% of motor threshold. Muscle evoked potentials (MEPs) were recorded from first dorsal interosseus (FDI), orbicularis oculi (o. oculi) and mentalis muscles. Result: TMS evoked MEPs in o. oculi on both ipsi- and contralateral sides in all subjects. In the paired-pulse study, MEP amplitude in the mentalis decreased …