In this experiment, the heads of 15 healthy male subjects were unilaterally exposed to a pulse-modulated EMF (GSM handset like signal) for 30 min prior to sleep. Exposure levels with 10g-averaged peak spatial specific SARs of 0.2 W/kg, 5 W/kg, or sham were made in a double-blind, crossover design. Sleep architecture was not affected by EMF exposure. Analysis of the sleep electroencephalogram (EEG) revealed a dose-dependent increase of power in the spindle frequency range in non-REM sleep. The magnitude of the effect of the previous experiment (Huber et al, 2002) conducted at 1 W/kg was between the responses of the two doses. Reaction speed decelerated with increasing field intensity in the 1-back task, while accuracy in the CRT and N-back task were not affected in a dose-dependent manner.
In summary, this is the fourth independent experiment and the first dose-response experiment demonstrating effects of GSM-like exposures on the spindle frequencies in non-REM sleep EEG.