26 subjects (13 male, 13 female) participated in 2 sessions, respectively: exposure and sham exposure. Each session was divided into a pre-exposure part, an exposure/sham exposure part and a post-exposure part. During each part, the resting EEG with open eyes and with closed eyes was measured repeatedly in separate runs for 3 minutes per run, respectively. Two runs were measured during the pre- and post-exposure parts, respectively, and 3 runs were measured during the exposure/sham exposure part.
|Duty cycle||12.5 %|
|Chamber||dimly lit, electrically shielded room|
|Setup||mobile phone was positioned against the left ear of subject and connected to a PC to control exposure; subjects were seated in a comfortable chair and a screen was placed in front of them to keep their eyes in a well-defined direction; interference of EEG electrodes with mobile phone was controlled; electrode impedance was controlled|
|Sham exposure||A sham exposure was conducted.|
During the exposure and post-exposure part, the alpha wave power was significantly decreased in the EEG with closed eyes in the exposure session compared to the sham exposure session. All other parameters did not show any significant differences between exposure and sham exposure.
The authors conclude that exposure to a 900 MHz electromagnetic field (GSM) might influence alpha waves in the resting EEG and thus the brain activity.