Here's cute little piece about multitasking and the executive system. There are a few ideas that get mixed around in this article, so let me try to tease them out...
1) The executive system is the theorized cognitive system that performs executive tasks such as planning, goal-maintenance, and switching. The article does a pretty good job of giving examples of these types of tasks (the short-order cook is a particularly good example), however it should be noted that while these functions are grouped together under the umbrella of "executive function", there are some distinctions among these tasks.
2) The executive system is thought to "reside" in the prefrontal regions of the brain (above your eyebrows). While lesion / brain damage and fMRI studies provide evidence for this, researchers are still figuring out how this part of the brain is capable of conducting these processes. We can't assume that other parts of the brain aren't also involved.
3) People tend to talk about the executive system in terms of a "humonculus" - the little human inside the brain. People in philosophy and psychology will tell you that this type of argument is always fallacious because it does not provide an adequate theory of mind; that is, if you use a little mind to explain a big mind, how do you explain the little mind?
I bring this up for two reasons. First, I just saw Inception (and you should too, if you want a way meta experience). Second, because the NPR piece uses an analogy of a cartoon conductor to describe the executive system. It may be a good analogy for the layperson, but it's not good science.
I'm working on some research that investigates how executive processes relate to science concept learning in order to better understand why some concepts are hard for kids (and even adults) to learn, as well as how instruction can be designed to overcome these difficulties. More to come...