The researchers speculated that a cellphone with its antenna placed elsewhere — near the phone's earpiece, for instance — might activate different regions in the brain.That the heightened activity occurred closest to the antenna, and not near the place where the phone was in direct contact with the head, signaled to the study's authors that the changes were a response to electromagnetic signals and not a reaction to the heat generated by the device.  The electromagnetic radiation emitted by a cellular phone's antenna appears to activate nearby regions of the brain to unusually high levels, according to a study published Tuesday in the Journal of the American Medical Assn. said study leader Dr. Nora Volkow, director of the National Institute on Drug Abuse , who researches how addiction affects the brain.Those effects could vary widely depending upon the location of a cellphone's antenna, the frequency on which it operates, and how long one uses the device, Volkow said.What the study does not suggest is that cellphone use contributes to the development of brain cancers. In their "live" phase, the phones in the experiment were connected to a recorded message, but the audio signal was muted, so subjects heard nothing. Cell phones were placed on the left and right ears and positron emission tomography with (18F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes (“on” condition) and once with both cell phones deactivated (“off” condition).
– The debate on the health risks of cell phones is probably going to get noisy for a few days. A prominent new study shows that if you use the phone for about an hour, the area of your brain nearest the antenna shows increased activity, reports Wired. “We have no idea what this means yet or how it works,” said the lead researcher, Nora Volkow of the National Institutes of Health. “But this is the first reliable study showing the brain is activated by exposure to cellphone radio frequencies.” The study is in the Journal of the American Medical Association and can be read in full here. "I can't overall say this is harmful but we have to study more for long-term effects," says Volkow. In the meantime, the by-now common advice to use a headset or speaker phone—especially teens, whose brains are more vulnerable—is probably wise, she says. The Los Angeles Times notes that the study may not be definitive, but "by providing solid evidence that cellphone use has measurable effects on brain activity, it suggests that the nation's passionate attachment to its 300 million cellphones may be altering the way we think and behave in subtle ways."