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Twenty-four subjects participated in this study. They were exposed to EM fields from a 900 MHz phone in "listening" mode, with 217 Hz pulse rate, 0.577µs pulse width, and an average power 3-4 mW. The subjects were also given sham exposure, without being aware of their exposure status. EEGs were performed while the subjects performed an auditory discrimination task for 3 minutes, and then for 2 minutes in the resting state. This pattern was repeated 3 times and the 20 minute series of tasks were performed 3 times, either with active phone exposure, or with an active phone exposure plus a purported EMF attenuator, or with neither the active phone or EMF attenuator. Mobile phone exposure resulted in the resting EEG in decreased 1-4 Hz activity in right hemisphere sites, and increasing 8-12 Hz activity as a function of exposure duration. There was no effect on task performance. The phone exposure also altered early phase-locked neural responses, attenuating the normal response decrement over time in the 4-8 Hz band, decreasing the response in the 12-30 Hz band globally and as a function of time, and increasing midline frontal and lateral posterior responses in the 35-40 Hz band. Since several of the noted effects were dependent on time, the authors conclude that the RF signal had only an indirect effect on brain activity. They also conclude that the temporal nature of this effect may contribute to the lack of consistent results reported in the literature.
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