The use of cell phones to talk, dial and send text has been the focus of concerns related to security issues, but the study at Carnegie Mellon University in Pittsburgh, the U.S. state of Pennsylvania for the first time, used magnetic resonance imaging of the brain to document the effect of the simple act of listening to the speaker during a call. The reduction in brain activity associated with the direction of a vehicle can cause the driver to move from one track to another erratically, as was observed in tests on 29 volunteers using a simulator. This is a common mistake among drunken drivers. Make connections with cell phones without necessarily having to hold them in hand is not sufficient to eliminate the distraction to drivers. They need to keep not only their hands on the wheel but also the brain concentrate on the street, said the neuroscientist Marcel Just, director of the Center for Cognitive Brain Image. Other distractions, like eating, listening to the radio or talking to a passenger, also can distract the driver from driving the vehicle, but it is not known how these activities can be compared to the use of cell phones, reducing the concentration of a driver in up to 37%, leading him to commit similar types of errors which occurred when driving drunk.