It's become the norm in our world to multitask, keeping ourselves insanely busy and even bragging about it. But while you may be able to do several things at once, don't expect to do them well -- especially if you're trying to juggle more than two similar tasks.
In the brain, the prefrontal cortex takes the lead in executing desires, sending a chain of impulses to the posterior of the brain that tell your body what to do to complete the action. This works fine when you have one task to complete. It's OK when you have two -- neurologists at a French biomedical agency discovered that when a second task is added, the brain divides the work between its two hemispheres. But trouble arises when three tasks are scheduled. In these cases, the French test subjects made more mistakes and often forgot one of the tasks [source: Telis].
Even with only two tasks, you might be a bit slower on each than if you tackled them separately. At Carnegie Mellon University, test subjects listened to complex sentences. Next, they compared pairs of figures. The neuroscientists scanned their brains and noted the amount of brain space used while they did both tasks. Then the subjects listened to the sentences and compared the figures at the same time. The amount of brain space used was not twice the amount when they performed the tasks separately. Instead, it was just slightly more than when doing one of the tasks [source: Blakeslee]. The scientists noted that the subjects were a bit slower than when they executed the tasks separately.
Think it’s efficient to listen to a foreign language CD while you're cooking dinner? Maybe not. Studies show that even if we do learn something while multitasking, we don't learn it as well as we would have if we devoted our full attention to it. Studies at UCLA show that when multitasking, areas of the brain necessary for memory retrieval may be occupied by the one task and pass the other task to a different part of the brain. You may learn your vocabulary words, but when it's time to use them, you may not be able to pull them out of your memory [source: Science Daily].
Multitasking is listed as a requirement in many job ads, but does multitasking necessarily correspond to more or better output from workers? Clifford Nass, a Stanford University professor who conducted research on multitasking, said, "People who multitask very, very frequently believe they are excellent at it and they're actually, as far as we can tell, the worst at it of any people [source: NPR]." Nass and his associates studied how multitaskers preformed at three crucial skills: being able to ignore information that is not important, being able to keep working memory organized and being able to switch among tasks. The study found that multitaskers performed poorly in all three areas [source: NPR].