Shared senior authorship.
Spindles and Slow Waves in Humans
Sleep EEG alterations: effects of pulsed magnetic fields versus pulse-modulated radio frequency electromagnetic fields
Article first published online: 22 JUN 2012
© 2012 European Sleep Research Society
Journal of Sleep Research
Volume 21, Issue 6, pages 620–629, December 2012
How to Cite
SCHMID, M. R., MURBACH, M., LUSTENBERGER, C., MAIRE, M., KUSTER, N., ACHERMANN, P. and LOUGHRAN, S. P. (2012), Sleep EEG alterations: effects of pulsed magnetic fields versus pulse-modulated radio frequency electromagnetic fields. Journal of Sleep Research, 21: 620–629. doi: 10.1111/j.1365-2869.2012.01025.x
Shared senior authorship.
- Issue published online: 27 NOV 2012
- Article first published online: 22 JUN 2012
- Accepted in revised form 29 April 2012; received 26 October 2011
- delta frequency;
- electromagnetic field;
- magnetic field;
- mobile phone;
- non-rapid eye movement;
- radio frequency;
- rapid eye movement;
- spindle frequency;
- theta frequency
Studies have repeatedly shown that electroencephalographic power during sleep is enhanced in the spindle frequency range following radio frequency electromagnetic field exposures pulse-modulated with fundamental frequency components of 2, 8, 14 or 217 Hz and combinations of these. However, signals used in previous studies also had significant harmonic components above 20 Hz. The current study aimed: (i) to determine if modulation components above 20 Hz, in combination with radio frequency, are necessary to alter the electroencephalogram; and (ii) to test the demodulation hypothesis, if the same effects occur after magnetic field exposure with the same pulse sequence used in the pulse-modulated radio frequency exposure. In a randomized double-blind crossover design, 25 young healthy men were exposed at weekly intervals to three different conditions for 30 min before sleep. Cognitive tasks were also performed during exposure. The conditions were a 2-Hz pulse-modulated radio frequency field, a 2-Hz pulsed magnetic field, and sham. Radio frequency exposure increased electroencephalogram power in the spindle frequency range. Furthermore, delta and theta activity (non-rapid eye movement sleep), and alpha and delta activity (rapid eye movement sleep) were affected following both exposure conditions. No effect on sleep architecture and no clear impact of exposure on cognition was observed. These results demonstrate that both pulse-modulated radio frequency and pulsed magnetic fields affect brain physiology, and the presence of significant frequency components above 20 Hz are not fundamental for these effects to occur. Because responses were not identical for all exposures, the study does not support the hypothesis that effects of radio frequency exposure are based on demodulation of the signal only.