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Abstracts
  • Schienle, A., Stark, R., & Vaitl, D. (1999). [EEG-changes caused by spherics]. Fortschritte Der Medizin, 117(1–2), 41–42.
  • Schienle, A., Stark, R., & Vaitl, D. (1999). Electrocortical responses of headache patients to the simulation of 10 kHz sferics. The International Journal of Neuroscience, 97(3–4), 211–224. https://doi.org/10.3109/00207459909000661

    Many headache patients believe that weather changes act as pain triggers. Therefore, the present study investigated the psychophysiological influence of an indicator of atmospheric instability, Very Low Frequency (VLF)-sferics, on 32 subjectively weather-sensitive women suffering from migraine attacks and/or tension-type headaches. It was analyzed if sferics exposure is able to induce electrocortical changes as well as headache symptoms. The subjects, who had been divided into two groups, participated in a sferics simulation study. The experimental group (n = 16) underwent a ten-minute exposure to 10kHz-sferics impulses followed by 20 minutes without treatment in order to examine possible prolonged sferics effects. The control group (n = 16) received no treatment. As dependent measures, EEG spectral power was compared between the two groups at six electrode sites (F3/F4; P3/P4; O1/O2). Sferics exposure provoked increases in absolute alpha and beta power during the treatment. The alpha power enhancement was still present at parietal sites at the end of registration (20 minutes after the end of exposure). The stimulation did not induce headache symptoms.

  • Vaitl, D., Gruppe, H., Stark, R., & Pössel, P. (1996). Simulated micro-gravity and cortical inhibition: a study of the hemodynamic-brain interaction. Biological Psychology, 42(1–2), 87–103. https://doi.org/10.1016/0301-0511(95)05148-1

    The present study was carried out to determine the inhibitory cortical processes induced by changes in hemodynamics. Previous experiments in humans conducted in our laboratory have shown that there is a close relationship between posture and delta and theta EEG activity. The most pronounced effects were obtained during the 6 degrees head-down tilt (HDT) position. In space medicine the HDT procedure is very frequently employed to simulate micro-gravity and to determine the neurohormonal counter-regulations evoked by the expansion of central volume. Twenty male subjects spent 23 h in bed in 6 degrees HDT and 23 h in 6 degrees HUT (head-up tilt) positions during which EEG (frontal, central, parietal, occipital), startle responses, and reaction-times were measured every 2 h (from 10:00 h till 20:00 h). The effects of cardiovascular deconditioning (CD) regularly occurring after HDT were assessed by examining orthostatic tolerance and the physical work capacity (bicycle ergometry). As expected, 23 h HDT led to more pronounced CD than HUT. Spectral power analyses of EEG revealed increases in delta and theta frequency hands similar to those found during HDT in previous EEG studies. In addition, subjects responded more slowly (S1-S2 reaction-time task) during HDT as compared with HUT bedrest. The influence of HDT on startle response, however, was not in keeping with the initial hypothesis (i.e. dampening of reflex activity). The EEG data and the sensorimotor performance indicated that the body fluid shift towards the thoracic cavity induced by HDT resulted in signs of cortical inhibition. In addition to neural mechanisms, other processes must be postulated which are closely related to the counter-regulation evoked by the varying body positions.

  • Schienle, A., Stark, R., Walter, B., Vaitl, D., & Kulzer, R. (1997). Effects of low-frequency magnetic fields on electrocortical activity in humans: a sferics simulation study. The International Journal of Neuroscience, 90(1–2), 21–36. https://doi.org/10.3109/00207459709000623

    A previously recorded electromagnetic impulse of natural origin, a 10 kHz-sferic, was simulated and presented to 20 subjects. The magnetic component of the signal with a maximum field amplitude of 50 nT and a duration of 500 microseconds was applied over a duration of 10 minutes with a pulse repetition rate that varied statistically between 7 and 20 Hz. After sferics exposure, an additional 20 minutes without treatment were recorded in order to examine possible prolonged effects of sferics stimulation. The control group (n = 20) received no treatment. As a dependent measure, electrocortical changes throughout the course of the experiment were determined by means of EEG spectral analysis and compared between the two groups. Sferics exposure provoked increases in alpha and beta power. The effect was present during stimulation and continued for 10 minutes after the end of treatment. A longer lasting influence of sferics exposure was displayed by subjects with a high degree in weather sensitivity, somatic complaints, and neuroticism, who continued to stay on an enhanced alpha power level until the end of registration (20 minutes after the end of exposure). With these results a general electrocortical sensitivity towards sferics as well as individual differences in sferics reactivity could be demonstrated.

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