But glucose metabolism in the regions closest to the antenna — the orbitofrontal cortex and the temporal pole — was significantly higher when the phone was turned on.
Further analyses confirmed that the regions expected to have the greatest absorption of radiofrequency and electromagnetic fields from cell phone use were indeed the ones that showed the larger increases in glucose metabolism.
“Even though the radio frequencies that are emitted from current cell phone technologies are very weak, they are able to activate the human brain to have an effect,” Dr. Volkow said in a JAMA video report.
The effects on neuronal activity could be due to changes in neurotransmitter release, cell membrane permeability, cell excitability, or calcium efflux.
It’s also been theorized that heat from cell phones can contribute to functional brain changes, but that is probably less likely to be the case, the researchers said.
Dr. Wang noted that the implications remain unclear — “further studies are needed to assess if the effects we observed could have potential long-term consequences,” he said — but the researchers have not yet devised a follow-up study.
“The take-home message,” Dr. Kesair said, “is that we still don’t know, more studies are needed, and in the meantime users should try to use headsets and reduce cell phone use if at all possible. Restricting cell phone use in young children certainly is not unreasonable.”
