So says a new study of the brain:
Why We Can't Do 3 Things at Once (LiveScience)
Do you think you can do more than two things at once? Or do you try to even though you can't?when faced with two tasks, a part of the brain known as the medial prefrontal cortex (MFC) divides so that half of the region focuses on one task and the other half on the other task. This division of labor allows a person to keep track of two tasks pretty readily, but if you throw in a third, things get a bit muddled.
"What really the results show is that we can readily divide tasking. We can cook, and at the same time talk on the phone, and switch back and forth between these two activities," said study researcher Etienne Koechlin of the Universite Pierre et Marie Curie in Paris, France. "However, we cannot multitask with more than two tasks."
and then there are those of us that have trouble making choices at all...The results might also explain why humans seem to have a hard time making decisions between more than two things, Koechlin said.
Previous work has indicated that people like binary choices, or decisions between two things. They have difficultly when decisions involve more than two choices, Koechlin said. When faced with three or more choices, subjects don't appear to evaluate them rationally; they simply start discarding choices until they get back to a binary choice.