Modality-specific Affective Responses and their Implications for Affective BCI

Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed understanding of the processes involved in emotions. To explore the modality-specific nature of affective responses, we studied neurophysiological responses of 24 subjects during visual, auditory, and audiovisual affect stimulation and obtained their subjective ratings. Coherent with literature, we found modality-specific responses in the EEG: parietal alpha power decreases during visual stimulation and increases during auditory stimulation, whereas more anterior alpha power decreases during auditory stimulation and increases during visual stimulation. We discuss the implications of these results for multimodal aBCI

Magnetization reversal and local switching fields of ferromagnetic Co/Pd microtubes with radial magnetization

Three-dimensional nanomagnetism is a rapidly growing field of research covering both noncollinear spin textures and curved magnetic geometries including microtubular structures. We spatially resolve the field-induced magnetization reversal of free-standing ferromagnetic microtubes utilizing multifrequency magnetic force microscopy (MFM). The microtubes are composed of Co/Pd multilayer films with perpendicular magnetic anisotropy that translates to an anisotropy with radial easy axis upon rolling-up. Simultaneously mapping the topography and the perpendicular magnetostatic force derivative, the relation between surface angle and local magnetization configuration is evaluated for a large number of locations with slopes exceeding 45 degrees. The angle-dependence of the switching field is concurrent with the Kondorsky model, i.e., the rolled-up nanomembrane behaves like a planar magnetic film with perpendicular anisotropy and a pinning dominated magnetization reversal. Additionally, we discuss methodological challenges when detecting magnetostatic force derivatives near steep surfaces

Soft sensor approach based on magnetic Barkhausen noise by means of the forming process punch-hole-rolling

The relevance of the magnetic Barkhausen noise (MBN) and the non-destructive characterization of material properties in near surface layers, has increased in recent years.With the development of new signal processing techniques, the method was further developed into a powerful evaluation technique and is used in various areas of online and offline measurement. In addition to the established use in the detection of grinding burn, the method is increasingly used in the context of soft sensors for property controlled processes, due to its short analysis times. By a detailed description of a soft sensor concept for the novel forming process punch-hole-rolling this work focuses on the offline characterization of the process specific cause-effect relationships. This is done by analyzing the process interactions as well as the surface layer state by a metallographic investigation. Additionally a non-destructive characterization by means of MBN was done and correlated with the surface layer state. This provides important findings for the use of a MBN-sensor in a soft sensor concept and the potential integration into the forming process

Bacteria Hunt: A multimodal, multiparadigm BCI game

Brain-Computer Interfaces (BCIs) allow users to control applications by brain activity. Among their possible applications for non-disabled people, games are promising candidates. BCIs can enrich game play by the mental and affective state information they contain. During the eNTERFACE’09 workshop we developed the Bacteria Hunt game which can be played by keyboard and BCI, using SSVEP and relative alpha power. We conducted experiments in order to investigate what difference positive vs. negative neurofeedback would have on subjects’ relaxation states and how well the different BCI paradigms can be used together. We observed no significant difference in mean alpha band power, thus relaxation, and in user experience between the games applying positive and negative feedback. We also found that alpha power before SSVEP stimulation was significantly higher than alpha power during SSVEP stimulation indicating that there is some interference between the two BCI paradigms

Neurologic Consultations and Headache during Pregnancy and in Puerperium : A Retrospective Chart Review

Headache is a common symptom during pregnancy and in puerperium that requires careful consideration, as it may be caused by a life-threatening condition. Headaches in pregnant women and women in puerperium are classified as primary or secondary; acute, severe and newly diagnosed headaches should prompt further investigation. We aimed to further characterise the demographic features, symptoms, examination findings, and neuroimaging results of cases of headache during pregnancy and in puerperium. All pregnant women or women in postpartum conditions who attended neurological consultations at the emergency department of the clinic for Gynaecology, Obstetrics and Reproductive Medicine of Saarland University/Germany between 2001/2015 and 2012/2019 were enrolled in this retrospective chart review. Data collected from the charts included demographic/pregnancy characteristics, clinical features and imaging findings. Descriptive statistics as well as binary logistic regression were performed. More than 50% of 97 patients had abnormal findings in their neurological examination. Magnetic resonance imaging findings were pathological for almost 20% of patients—indicating conditions such as cerebral venous thrombosis, reversible posterior leukoencephalopathy, brain tumour and intracranial bleeding. The odds of abnormal neuroimaging results were 2.2-times greater among women with abnormal neurological examination findings than among those with normal examination results. In cases of headache during pregnancy and in puerperium, neuroimaging should be indicated early on. Further research is needed to determine which conditions indicate a need for immediate neuroimaging

Why we fail: mechanisms and co-factors of unsuccessful thrombectomy in acute ischemic stroke

Purpose Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke. However, recanalization fails in about 16.5% of interventions. We report our experience with unsuccessful MT and analyze technical reasons plus patient-related parameters for failure. Methods Five hundred ninety-six patients with acute ischemic stroke in the anterior circulation and intention to perform MT with an aspiration catheter and/or stent retriever were analyzed. Failure was defined as 0, 1, or 2a on the mTICI scale. Patients with failing MT were analyzed for interventional progress and compared to patients with successful intervention, whereby parameters included demographics, medical history, stroke presentation, and treatment. Results One hundred of the 596 (16.8%) interventions failed. In 20 cases, thrombus could not be accessed or passed with the device. Peripheral arterial occlusive disease is common in those patients. In 80 patients, true stent retriever failure occurred. In this group, coagulation disorders are associated with poor results, whereas atrial fibrillation is associated with success. The administration of intravenous thrombolysis and intake of nitric oxide donors are associated with recanalization success. Intervention duration was significantly longer in the failing group. Conclusion In 20% of failing MT, thrombus cannot be reached/passed. Direct carotid puncture or surgical arterial access could be considered in these cases. In 80% of failing interventions, thrombus can be passed with the device, but the occluded vessel cannot be recanalized. Rescue techniques can be an option. Development of new devices and techniques is necessary to improve recanalization rates. Assessment of pre-existing illness could sensitize for occurring complications

Revisiting Tell Begum. A Prehistoric Site in the Shahizor Valley, Iraqi Kurdistan

Tell Begum was previously explored by Iraqi archaeologists in the 1960s when excavations revealed a multi-period site. Among the key finds were Halaf period remains that are relatively rare in the region of the Shahrizor plain and included polychrome ceramics suggesting a local variation of the Halaf culture. Recent investigations and excavations in 2011 and 2013 revealed a 5 hectare site inhabited during the Halaf, Ubaid, Late Chalcolithic, and medieval periods. The Halaf site may have had an area of about 3 hectares, making it a relatively large settlement for that period, although its full extent is unclear. Offsite work revealed the area to have been well watered in the past, with likely neighbouring regions of woodland and abundant shrubs. The heavy sedimentation in the region has partially obscured archaeological remains, including possibly Tell Begum's lower mound. The site, nevertheless, shows continuity of settlement, indicating relative stability in settlement over long timespans

Latest Developments from the S-DALINAC*

The S-DALINAC is a 130 MeV superconducting recirculating electron accelerator serving several nuclear and radiation physics experiments as well as driving an infrared free-electron laser. A system of normal conducting rf resonators for noninvasive beam position and current measurement was established. For the measurement of gamma-radiation inside the accelerator cave a system of Compton diodes has been developed and tested. Detailed investigations of the transverse phasespace were carried out with a tomographical reconstruction method of optical transition radiation spots. The method can be applied also to non-Gaussian phasespace distributions. The results are in good accordance with simulations. To improve the quality factor of the superconducting 3 GHz cavities, an external 2K testcryostat was commissioned. The influence of electro-chemical polishing and magnetic shielding is currently under investigation. A digital rf-feedback-system for the accelerator cavities is being developed in order to improve the energy spread of the beam of the S-DALINAC. * Supported by the BMBF under contract no. 06 DA 820, the DFG under contract no. Ri 242/12-1 and -2 and the DFG Graduiertenkolleg 'Physik und Technik von Beschleunigern