What used to be considered harmless conversations have cell phone users thinking about the consequences.

After talking on a mobile phone for just 50 minutes, activity increases in brain cells, according to a study published in the Journal of the American Medical Association.

Researchers said mobile phones that are turned off did not create the same brain activity. They said more research should stem from this study because the lasting effects of brain activity are unknown.

Dr. Nora Volkow, the lead author of the study and a neuroscientist for the National Institutes of Health, said the study looked at how electromagnetic radiation from cell phones affects glucose metabolism in the brain.

“The findings are an indication that exposure to cell phones activate the brain much more easily than we previously thought,” Volkow said.

She said brain activity means the brain cells use glucose to create energy. What is still unknown about the study is whether the effect of artificially activating brain cells will be negative or positive. Rhonda Burton, a third-year in fashion and retail studies, said cell phone usage is such a large part of society, she’s not sure such research would affect students.

“Your cell phone is a part of your identity,” Burton said. “I can’t stand not having it on me at all times.”

Robert Hayes, a fourth-year in English, said he doesn’t know the physical effects that cell phones will have in the future.

“In terms of physical health, I really don’t know the effects that cell phones will have,” Hayes said. “But mental health-wise, I think that cell phones have and will continue to transform our society.”

The study included 47 healthy adults — a small group that researchers said was scientifically valid for this type of research. The publication said researchers tested levels of brain activity when the phone was in use and placed against the head versus when the phone was against the head, but turned off. The session lasted 50 minutes.

Subjects who had the phone turned on had “significantly higher” brain activity in the region closest to the antenna compared to those who did not have the phone on, according to the study.

Volkow said she does not know whether the artificial activation of brain cells will have long-term negative effects, which is why researchers are calling for further investigation.

Volkow’s advice: Keep your cell phone away from your head.

“The human brain is sensitive to electromagnetic radiation emitted by cell phones, but for the brain to be impacted, the cell phone has to be close to the head,” she said.

Volkow said since she began her research career, she always uses a wire earpiece because the effects of this radiation are still unknown.

The research sparked another study conducted that concluded a majority of the radiofrequency energy emitted by a mobile phone is absorbed by the hand and head of its user. The study was also published in the Journal of the American Medical Association.

“In addition to concerns about potential harmful effects of such exposure, such as the issue of risk of brain cancer, change in brain function related to cell phone radiofrequencies is also a concern,” the publication reads. “Studies have been conducted to investigate the effect of cell phone use on brain electrical activities, neurophysiology, and behavior.”