Researchers at the University of Texas at Austin studied 800 cell phone users to measure cognitive ability and concentration. They found that if a study participant’s cell phone is within visual range, the participant performs worse on cognitive tasks — even when the phone is turned over, or turned off. Phones must be outside the room and out of sight for participants to be able to fully concentrate on tasks. This effect is even more pronounced with people who self-identify as “dependent” on their cell phones.
Read more: The mere presence of your smartphone reduces brain power, study shows