Quoting here from the article, "Even though people feel entertained, even relaxed, when they multitask while exercising, or pass a moment at the bus stop by catching a quick video clip, they might be taxing their brains, scientists say. 'People think they’re refreshing themselves, but they’re fatiguing themselves,' said Marc Berman, a University of Michigan neuroscientist."
More and more I see people walking, jogging, and riding bikes with earbuds in place. I have not yet succumbed to becoming surgically attached to my i-Pod, but on a trip back east a couple of years ago, Kathy let me use hers during a train trip from New York City to Connecticut. I was amazed at the effect it had on my brain. It was like watching a movie of my life playing out in front of me, while the soundtrack played inside my head. Indeed, I had a hard time concentrating on what I was seeing as my brain tried to multitask between the aural and visual stimulation.
One solution, of course, is to have time during the day when we turn off the stimulation. All of us have at least brief moments during our day when we can just be. The tendency is now turning toward filling these "micro-moments" with texting, mobile gaming, and checking e-mail. I would suggest that these ways of "killing time" are incrementally killing our ability to process our lives as they are being lived.
So maybe the answer is as simple as leaving the i-Pod at home and taking a walk while listening to the sounds of the real world.
Here's a link to the New York Times article: http://www.nytimes.com/2010/08/25/technology/25brain.html?src=tp