Get social with me on twitter and Instagram @DanielCalbacho

Drivers seem comfortable lighting up a smoke, changing stations on the radio or chatting on their cell phones while navigating the streets. But brain researchers say it's a terrible idea to do more than one thing at a time, particularly using a cell, even with a hands-free device.

"If you're driving while cell-phoning, then your performance is going to be as poor as if you were legally drunk," says David Meyer, a psychology professor at the University of Michigan. I’ve even seen a YouTube video where they tested students attempting their drivers’ license. They intoxicated a group, then tested them. They then tested a second group who were to text and drive. The findings were scary – the drunk test group did far better with the pre-consumed texting group driving over directional cones. "If you test people while they're texting or talking on the phone, they will miss a lot of things that are in their visual periphery," says Earl Miller, a neuroscientist at the Massachusetts Institute of Technology.

Driving requires a surprising amount of brain power. Out on the road, we should process huge amounts of visual information, predict the actions of other drivers and coordinate precise movements of our hands and feet.

Even when using a hands-free device, scientists have found that talking on the phone distracts us to the point where we devote less brain power to focusing on the road.

Drivers' Brains on Cell Phones

Marcel Just, a neuroscientist at Carnegie Mellon University, says that's why people learning to drive don't do anything else.

"Novice drivers turn off the radio; they ask you not to talk to them. They need all the brain participation they can get for the driving," Just says.

But the level of focus required changes with experience. Over time, the brain rewires itself to do the tasks involved in driving. So, when our eyes see a red light, our foot hits the brake, with no conscious thought involved. Driving becomes automatic. You may even find yourself arriving at some destination and not remembering much about the trip. That’s called driving on Autopilot.

Scientists call this phenomenon "automaticity." It lets us do one thing while focusing on something else. In other words, learning to do one task automatically helps us to multitask.

If the brain is so good at this, why not chat on the cell phone while driving? Experts came up with a demonstration that's a bit more refined.

Pushing the Brain — Concerts and Conversation

A professional pianist was brought into a special studio. For over an hour, the musician was tasked with playing a range of pieces, some he knew and some he had to sight-read. While he was playing, he was asked to multitask. Sometimes the additional work was simple. But when the challenges took more brain power, it was tougher for the musician to answer questions and play the piano at the same time.

There's a lot going on in the pianist's brain. Several circuits are busy decoding and producing language. And that's only the beginning.

Neuroscience studies using brain scans have shown that the brain struggles with paying attention to sights and sounds simultaneous. When the brain starts working on a visual task, its auditory parts show decreased activity, and vice versa.

Brain Overload, Something's Gotta Give

The musician, who was already working hard to follow the music, simply couldn't handle something else that required real thinking. It's like driving on an unfamiliar road and getting a cell phone call from an angry spouse. You may not notice that stopped car up ahead.

In fact, driver inattention is involved in about 80 percent of crashes, according to a 2006 study by the National Highway Traffic Safety Administration. The 100-Car Naturalistic Driving Study found the most common distraction for drivers was the use of cell phones — with the number of crashes attributable to dialing nearly identical to the number associated with talking or listening.

What was learned from the experiment was that multitasking, while thought to be possible by many, is not realistic. The brain must switch modes. Switching modes takes time — maybe only a quarter of a second. But on a highway, that means you've gone an extra 20 meters before you hit the brake.

So next time you feel tempted to try and engage with your phone while driving, remember that people far cleverer than you or I have proved it doesn’t work – the infographic below shows this clearly.