People have debated the desirability and efficacy of multitasking for decades. Recently, an article by Rachael Rettner entitled "Why We Can't Do 3 Things at Once" reports on a new study related to the brain and multitasking.
Researchers said that when faced with two tasks, the brain's medial prefrontal cortex (MFC) divides so that half of the region focuses on one task and the other half on the other task. And what happens when you attempt a third task? Things get muddled. Check out the article yourself. It's fascinating!