LYNN NEARY, host:
Multitasking is a way of life for kids - chatting online or on the cell phone, studying, surfing the Internet, quickly bouncing back and forth from one activity to the next.
UCLA psychology professor Russell Poldrack wanted to find out how this type of functioning affects the brain. Does a kid who's instant messaging his friends with a TV in the background learn as much from the history textbook as the kid who's at the desk in a quiet room?
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NEARY: Russell Poldrack has published a study on multitasking. He joins us now from NPR West. Good to have you with us.
Professor RUSSELL POLDRACK (UCLA): Thank you. It's a pleasure to be here.
NEARY: Maybe you could explain exactly what you looked at in your study first.
Prof. POLDRACK: We used a technique to image the brain called functional magnetic resonance imaging, or FMRI and this technique lets us look at what the brain is doing while a person is engaged in a task. The question we asked was, do the brain systems that are involved in learning differ in their activity depending on whether the person is focused on learning or whether they're distracted at the same time?
So we compared people under some condition of learning a very simple task, basically learning to categorize some simple shapes into different categories, and they learned under different conditions. Some of the time they learned while they were focused on the task and other times they learned while they were also doing something else at the same time, while they were distracted.
NEARY: And what did you discover?
Prof. POLDRACK: That learning while you are distracted fundamentally changes the brain systems that are involved in learning. When you learn while you're focused on a task, you engage a set of brain systems called the hippocampus, which are responsible for generating and storing sort of rich, complex, conscious memories of the past.
Whereas, when people learned under a dual task condition while they were distracted, they were more likely to engage a different set of brain regions called the basal ganglia, which are more involved in building habits and much less flexible types of knowledge.
NEARY: But there are benefits to multitasking, aren't there?
Prof. POLDRACK: There certainly are. In today's society we can't get by without multitasking, but what psychologists have discovered, whenever we multitask, we perform worse than we do if we focus on a task. And the idea is that we can't really do two things at a time, and there's a cost to that switching back and forth.
NEARY: Does your research indicate that there really are certain kinds of tasks that we need to have our undivided attention focused on, that there are certain things that we do that we really shouldn't be trying to multitask at the same time?
Prof. POLDRACK: Well, our research suggested that that's the case when you're trying to learn new information, because it's clear that learning is badly impaired when you're doing it while you're also doing other things. So it suggests, for example, that if a kid is trying to learn a history lesson, for example, the one thing they really don't want to be doing is, at the same time, you know, being on the Web or being on their cell phone texting friends, because that's going to be really detrimental to learning.
NEARY: On the other hand, in today's world it's almost impossible, even for an adult, to go someplace in a quiet room and just concentrate on one thing at one time. Our workplace demands multitasking.
Prof. POLDRACK: That's true. And I think the point of - that we have to take from the research is that we have to be aware that there is a cost to the way that our society is changing, that humans are not built to work this way. We're really built to focus. And when we sort of force ourselves to multi-task we're driving ourselves to perhaps be less efficient in the long run even, though it sometimes feels like we're being more efficient. There's a sort of myth of multi-tasking, I think, that when people are juggling lots of things they feel like they're doing more and it becomes kind of a self-fulfilling prophecy, that they keep juggling more things because they feel like they're doing it well, when in the end we may be actually hurting ourselves.
NEARY: So is this generation going to be really substantially different from their parents because of the way they work?
Prof. POLDRACK: That is the million-dollar question. I think we just simply don't know the answer to that. You know, once kids who are growing up today start becoming adults, then we'll be able to see, as adults, do they really differ from what adults look like who didn't grow up in such a fast-paced multi-tasking society. What we know about the brain is that it's very adaptable but at the same time there are built-in fundamental limits to the kinds of information the brain can process, and it may be that the ability to really do multiple things at once might be one of those built-in limits.
Now, one thing I should add is, the research doesn't necessarily extend to cases where the information is just in the background; so for example sending text messages compared to things like listening to music or having television on in the background, because the research is really focused on kind of active multi-tasking.
NEARY: Russell Poldrack is a professor of behavioral neuroscience at the University of California, Los Angeles. Thank you very much, Professor.
Prof. POLDRACK: Sure. It's a pleasure.
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