Influence of an alternating 3 Hz magnetic field with an induction of 0.1 millitesla on chosen parameters of the human occipital EEG

Neurosci Lett. 1997 Dec 19;239(2-3):57-60. doi: 10.1016/s0304-3940(97)00881-1.


In 62 volunteers it was studied, whether an alternating 3 Hz magnetic field (induction 0.1 mT) vertically applied to the head over a period of 20 min causes changes in EEG parameters. The study's design was a random crossover controlled, blind one. The field was generated by a Helmholtz coils arrangement. The occipital surface EEGs (O1 and O2) were derived against the left earlobe. Significant differences (two-tailed P < 0.05) between sham and real exposure were found for the relative spectral amplitudes of the theta (3.5-7.5 Hz) and beta band (12.5-25.0 Hz) and the theta/beta ratio. These observations can be interpreted as a more pronounced reduction of alertness under the real field condition compared with the control.

MeSH terms

  • Adolescent
  • Adult
  • Electroencephalography / methods
  • Electromagnetic Fields*
  • Female
  • Fourier Analysis
  • Humans
  • Male
  • Middle Aged
  • Random Allocation
  • Single-Blind Method
  • Visual Cortex / physiology*
  • Visual Cortex / radiation effects