[EEG changes during exposure to extremely low frequency magnetic field on a small area of brain]

ABSTRACT

Effects of extremely low frequency magnetic fields [ELF-MF] with different intensities and frequencies has been investigated by several researchers. In most of these studies, the applied magnetic field has uniformly encountered whole brain and it has shown that changing intensity and frequency causes anomaly changes in electroencephalograms. The aim of current study was to investigate the effect of local exposure to ELF-MF with different intensities on EEG signals. Magnetic field with frequency of 10 Hz and intensity of 100, 120, 160, 200, 240, 280, 320 and 360 micro T was applied to F3 zone in 10-20 system of 3 men locally. Finally, relative power spectrum in 5 points of head in conventional frequency bands was assessed. An increase in alpha band in regions under exposure such as F3 and O1 in intensities of 100 and 360 micro T was observed. No changes in other bands such as theta band were found. It should be noted that none of the above effects was observed in closed-eye position. Regular effects due to increasing intensity of magnetic field was not observed and changing potential of EEG signals from magnetic field with intensity of 100 and 360 micro T is more than other intensities. Changing pattern of alpha band in F4, Cz, O2 and O1 was similar to exposed F3 zone and no resonance effect was observed at 10 Hz magnetic field