The Effects of a Cell Phone on an EEG

Cell phones work by emitting radio waves which transmit communications. The proximity of the phone to the human head while in use, and concerns about the effects of prolonged exposure to even low levels of radiation, have prompted questions about cell phone safety. The electroencephalograph (EEG) is a graphic record of electric activity in the brain. EEG activity--brain activity--is generally constant, although there are patterns characteristic of waking and sleep states. EEG tests often measure changes in responses when subjects are asked to perform simple tasks or respond to stimuli. A change in EEG response is not of clinical concern, but an absence of EEG response to stimuli could be troubling. The EEG can show abnormalities in brain activity which may be symptomatic of adverse health conditions.

No Effect

• Some researchers found no effect of phone use on EEG.

  A number of studies reported no effect on EEG of cell phone use. For example, a 2000 study of healthy subjects in Finland (Hietanen et al.) observed no EEG effect from exposure to a range of cell phones. Similarly, a 2006 study by Yuasa et al. found no effect on the sensory cortex following 30 minutes' exposure to cell phone radiation.

Changes in EEG Activity

• Most studies, however, report effects of some kind.

  Other researchers have reported a variety of different changes in EEG activity in different experimental contexts. Jech et al., in 2001, reported EEG changes in the right hemisphere and a decrease in response time of 20 milliseconds to visual stimuli when subjects were exposed to cell phone radiation. In 2004, Krause et al. reported a decrease in EEG activity and an increase in errors associated with cell phone exposure during an auditory memory test. A further study by Krause in 2006 found decreased performance in auditory memory tasks in a group of children exposed to cell phone radiation. In the same year, Maby reported changes in activity in the frontal area of the brain associated with cell phone exposure. None of these changes were reported to be of clinical significance, and they were reversible after exposure ceased.