Driving really requires 100% of our attention. When we speak on the cell phone while we are driving, we may think we are multi tasking. In fact, our brains do not really “multi task”. Our attention is divided between activities, and our brain switches quickly from one activity to the other.
The danger of talking on a cell phone while driving lies in the fact that the brain can’t process separate streams of information efficiently. Furthermore, it is “hard-wired” to prioritize attention to the cell phone conversation. Since words spoken during a cell phone conversation “disappear” once they are spoken, the brain must attend closely to the audio information to be sure it captures the conversation. The visual view of the road or highway does not change as rapidly as the audio information, so the brain periodically ignores some of the visual information. Also, when people are talking on the phone, they are not just talking; they are seeing all kinds of images in their mind.
This visualization may be harmless most of the time, but it can be a real tragedy when a pedestrian steps into traffic or a car swerves into another lane. When we are talking on the phone, the brain lacks the processing power to react quickly enough to these changing situations.
Conversely, driving and talking to a passenger in the car is not dangerous because adult riders help keep the driver alert and can also point out dangerous conditions, and are quieter in heavy traffic or hazardous weather.
So which cognitive skills are most affected by cell phone use?
Attention, visual scanning, information processing and decision making are the most affected cognitive skills. When you think about driving, you realize how much you need these cognitive skills, and how risky it could be to reduce the effectiveness of any of these functions when you’re driving.
The bottom line is that talking on the cell phone while driving is dangerous. Safe driving is not just about keeping our eyes on the road and our hands on the wheel; it’s about focusing our brains on one of the most cognitively-challenging activities we routinely perform.