In a previous study it was shown that after a 15 min exposure to a pulsed extremely low frequency magnetic field, with most power at frequencies between 0 and 500 Hz, human brain electrical activity is affected, specifically within the alpha waves frequency (8-13 Hz) (see publication 10628).
853 ms segment consisting of 18 pulses with each pulse having a maximum rise of 1 ms. Each pattern consised of a pulse segment followed by varying refractory periods of 110, 220, 330 ms plus a constant fourth period of 5000 ms after which another pulse segment (853 ms) was delivered. This pattern was repeated for 15 min.
|magnetic flux density||200 µT||peak value||unspecified||-||-|
Occipital alpha waves activity (8-13 Hz) decreased during exposure to a pulsed extremely low frequency magnetic field compared to sham exposure. This effect was revealed after the first 5 min of a 15 min irradiation and was dependent on the magnetic field/sham order of exposure. This decrease was no longer significant in the first minute post-exposure, compared to sham exposure.
(Discrepancies between the current results and the data of the previous study suggest that the EEG changes may be sensitive to the characteristics of the magnetic field pulse train).