Vera Brümmer
German Sport University Cologne
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Featured researches published by Vera Brümmer.
NeuroImage | 2008
Stefan Schneider; Vera Brümmer; Heather Carnahan; Adam Dubrowski; Christopher D. Askew; Heiko K. Strüder
Basic changes in environmental conditions are fundamental to understanding brain cortical mechanisms. Several studies have reported impairment of central nervous processes during weightlessness. There is ongoing debate as to whether these impairments are attributable to primary physiological effects or secondary psychological effects of the weightlessness environment. This study evaluates the physiological effects of changed gravity conditions on brain cortical activity. In a first experiment, EEG activity of seven participants was recorded at normal, increased and zero gravity during a parabolic flight. Additionally an EEG under normal gravity conditions preflight was recorded. In a second experiment, 24 participants were exposed to a supine, seated and 9 degree head-down tilt position while EEG was recorded. Data were analysed using low resolution brain electromagnetic tomography (LORETA). Beta-2 EEG activity (18-35 Hz) was found to be increased in the right superior frontal gyrus under normal gravity conditions inflight. By exposure to weightlessness a distinct inhibition of this activity within the same areas could be noticed. As the tilt experiment showed changes in the left inferior temporal gyrus in supine and tilted positions we conclude that the observed changes under weightlessness are not explainable by hemodynamic changes but rather reflect emotional processes related to the experience of weightlessness. These findings suggest that weightlessness has a major impact on electro cortical activity and may affect central nervous and adaptation processes.
Behavioural Brain Research | 2010
Stefan Schneider; Vera Brümmer; Heather Carnahan; Jens Kleinert; Maria Francesca Piacentini; Romain Meeusen; Heiko K. Strüder
Confinement studies are performed to simulate the psychological effects that may be experienced on a long-term space flight. A general psycho-physiological model assumes that mood and cognitive functioning are impaired during confinement as a result of an absence of physical activity. The aim of the MARS500 study initiated by the Institute of Biomedical Problems (IBMP) and the European Space Agency (ESA) is to gather data, knowledge and experience to help prepare for a real mission to Mars. A test run with 105 days of isolation was performed prior to 520 days of isolation. Psycho-physiological data of this study are presented here. We hypothesized that exercise, as it has been shown in laboratory settings, would be able to prevent and counteract mood changes during isolation. Electrocortical data (EEG) and a self report on current psychological and physical state were recorded several times prior to and after exercise during the isolation period. Data revealed a clear effect of exercise on mood and electrocortical activity. Moreover, it was shown that mood and brain cortical activity decreased during the first 11 weeks of isolation and reached baseline again in the last week of isolation. A correlation analysis revealed a significant relation between mood data and electrocortical activity. We conclude (1) that confinement is accompanied by psycho-physiological changes and (2) that exercise is a suitable method to counteract psycho-physiological deconditioning during confinement.
Journal of The American College of Surgeons | 2008
Ryan Brydges; Allison Kurahashi; Vera Brümmer; Lisa Satterthwaite; Roger Classen; Adam Dubrowski
BACKGROUND Proficiency-based residency training programs can be more efficient than the current duration-based formats. For their successful implementation, appropriate proficiency criteria must be developed. The objective of this study was to investigate the relationship between technical skill performances assessed using computer- and expert-based methods and training year. An assumption was that asymptotes in performance as a function of training year can be used to set the proficiency level for a technical skill, so the value at which the asymptote occurs can be labeled as the proficiency criteria. STUDY DESIGN Thirty-eight general surgery residents performed one-handed knot tying on bench-top simulators at two levels of difficulty: superficial and deep. Motion-efficiency measures and expert-based measures were used to evaluate performance. Total number of operations (ie, surgical volume) that each trainee participated in during residency was also acquired. RESULTS On the superficial model, asymptotes were observed at year 1 for motion-efficiency and year 3 for expert-based measures. On the deep model, asymptotes were observed at year 2 for motion-efficiency and year 4 for expert-based measures. CONCLUSIONS The data demonstrate the challenges associated with defining technical skills proficiency criteria. Different asymptotes were observed for the two assessment methods and neither covaried substantially with surgical volume. These data suggest that this asymptote approach in defining proficiency criteria can be suitable for development of proficiency-based residency training programs. The sensitivity of this approach to the type of assessment method and to the functional difficulty of the simulators used for assessment must be considered.
Stress | 2009
Stefan Schneider; Christopher D. Askew; Vera Brümmer; Jens Kleinert; Simon Guardiera; Thomas Abel; Heiko K. Strüder
Previous findings of decreased mental and perceptual motor performance during parabolic flights have been attributed mainly to the primary effects of weightlessness rather than the accompanying effects of stress and altered mood. Although recent studies have alluded to the possible negative effects of stress on performance, there has been no attempt to investigate this during parabolic flights. Over a period of 3 years, 27 human participants (male n = 18, mean age ± SD 34.67 ± 7.59 years; female n = 9, 36.22 ± 9.92 years) were recruited with the aim to evaluate if, and to what extent, parabolic flights are accompanied by changes in mood. Furthermore, the relationships between mood and physiological markers of stress and arousal, namely circulating stress hormones (ACTH, cortisol, epinephrine, norepinephrine, prolactin and brain activity (EEG)) were investigated. A strong and significant correlation was found between circulating stress hormone concentrations and perceived physical state, motivational state (MOT) and psychological strain (PSYCHO), whereas no interaction between mood and EEG or EEG and stress hormone concentrations was observed. Therefore, two different stress responses appear to be present during parabolic flight. The first seems to be characterised by general cortical arousal, whereas the second seems to evolve from the adrenomedullary system. It is likely that both these mechanisms have different effects on mental and perceptual motor performance, which require further investigation and should to be taken into account when interpreting previous weightlessness research.
Neuroscience Letters | 2010
Tobias Vogt; Stefan Schneider; Vera Brümmer; Heiko K. Strüder
Numerous studies have been made in recent years addressing the effect of physical exercise on brain cortical activity and changes in mood. This research, however, was restricted to inadequate study designs in the elderly. In these times of an aging society, with the daily increasing interest in the benefits of physical exercise, investigations of the interrelationships of psycho-physiological elements of physical exercise seem to be progressively necessary. Using the model of frontal asymmetry, we hypothesized, that physical exercise by elderly persons at a self-selected pace increases left frontal alpha activity and is associated with a shift in mood to the positive. An electroencephalography (EEG) on two frontal positions (Fp1, Fp2) was made before and after walking at a self-selected pace for 45-60min and the state of the respective moods noted. The equation (right-left)/(right+left) was used to calculate frontal asymmetry as a marker of approach-related emotions. Key findings after walking were (1) a shift of the alpha-1 (7.5-10.0Hz) activation towards the right frontal brain areas as well as (2) an improvement in mood. Based on the frontal asymmetry model, an increase in the alpha-1 activation (p<0.05) might be associated with approach-related emotions. In conclusion, there is reason to believe that physical exercise programmes, as commonly practiced by the elderly, have beneficial effects on their general feeling of well-being. We were able to demonstrate this in this pilot study by applying only a comparatively simple and economically viable method.
Experimental Brain Research | 2008
Stefan Schneider; Vera Brümmer; Andreas Mierau; Heather Carnahan; Adam Dubrowski; Heiko K. Strüder
Previous studies showed that changing forces of gravity as they typically occur during parabolic flights might be responsible for adaptional processes of the CNS. However, until now it has not been differentiated between primary influences of weightlessness and secondary influences due to psycho-physiological factors (e.g., physical or mental strain). With the aim of detecting parabolic flight related changes in central cortical activity, a resting EEG was deduced in 16 subjects before, during and after parabolic flights. After subdividing EEG into α-, β-,δ- and θ-wave bands, an increase in β-power was noticeable inflight, whereas α1-power was increased postflight. No changes could be observed for the control group. To control possible effects of cortical activation, a manual tracking task with mirror inversion was performed during either the phase of weightlessness or during the normal gravity phase of a parabolic flight. No differences in performance nor in adaptation could be observed between both groups. A third group, performing under normal and stress-free conditions in a lab showed similar tracking values. We assume that the specific increase in brain activity is a sign of an increase in arousal inflight. This does support previous assumptions of non-specific stressors during parabolic flights and has to be considered as a relevant factor for experiments on central nerve adaptation. Although no influences of stress and/or weightlessness on motor perfromance and adaptation could be observed, we suggest that an “inflight” control group seems to be more adequate than a laboratory control group to investigate gravity-dependent changes in motor control.
Journal of Visualized Experiments | 2011
Vera Brümmer; Stefan Schneider; Tobias Vogt; Heiko K. Strüder; Heather Carnahan; Christopher D. Askew; Roland Csuhaj
Previous studies of cognitive, mental and/or motor processes during short-, medium- and long-term weightlessness have only been descriptive in nature, and focused on psychological aspects. Until now, objective observation of neurophysiological parameters has not been carried out--undoubtedly because the technical and methodological means have not been available--, investigations into the neurophysiological effects of weightlessness are in their infancy (Schneider et al. 2008). While imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI) would be hardly applicable in space, the non-invasive near-infrared spectroscopy (NIRS) technique represents a method of mapping hemodynamic processes in the brain in real time that is both relatively inexpensive and that can be employed even under extreme conditions. The combination with electroencephalography (EEG) opens up the possibility of following the electrocortical processes under changing gravity conditions with a finer temporal resolution as well as with deeper localization, for instance with electrotomography (LORETA). Previous studies showed an increase of beta frequency activity under normal gravity conditions and a decrease under weightlessness conditions during a parabolic flight (Schneider et al. 2008a+b). Tilt studies revealed different changes in brain function, which let suggest, that changes in parabolic flight might reflect emotional processes rather than hemodynamic changes. However, it is still unclear whether these are effects of changed gravity or hemodynamic changes within the brain. Combining EEG/LORETA and NIRS should for the first time make it possible to map the effect of weightlessness and reduced gravity on both hemodynamic and electrophysiological processes in the brain. Initially, this is to be done as part of a feasibility study during a parabolic flight. Afterwards, it is also planned to use both techniques during medium- and long-term space flight. It can be assumed that the long-term redistribution of the blood volume and the associated increase in the supply of oxygen to the brain will lead to changes in the central nervous system that are also responsible for anaemic processes, and which can in turn reduce performance (De Santo et al. 2005), which means that they could be crucial for the success and safety of a mission (Genik et al. 2005, Ellis 2000). Depending on these results, it will be necessary to develop and employ extensive countermeasures. Initial results for the MARS500 study suggest that, in addition to their significance in the context of the cardiovascular and locomotor systems, sport and physical activity can play a part in improving neurocognitive parameters. Before this can be fully established, however, it seems necessary to learn more about the influence of changing gravity conditions on neurophysiological processes and associated neurocognitive impairment.
Medicine and Science in Sports and Exercise | 2011
Vera Brümmer; Stefan Schneider; Thomas Abel; Tobias Vogt; Heiko K. Strüder
Physiology & Behavior | 2009
Stefan Schneider; Vera Brümmer; Thomas Abel; Christopher D. Askew; Heiko K. Strüder
European Journal of Applied Physiology | 2007
Stefan Schneider; Vera Brümmer; Simon Göbel; Heather Carnahan; Adam Dubrowski; Heiko K. Strüder