This is the third in an occasional series called 'Ask a Neuroscientist.' We're taking audience-submitted questions to David Eagleman, a neuroscientist at Baylor College of Medicine in Houston, to learn more about how the brain works.
Craig: Are there physical brain differences between good multi-taskers and single-focused individuals?
David Eagleman: The general story is that presumably, all personality differences have corresponding brain differences. And that's because we are our brains. And we know this because when people, for example, damage their brains, their personality can change entirely. And I mean even small bits of damage, let's say from a little stroke, can change somebody's risk aversion or personality or capacity to simulate the future, things like that.
So we know that your personality is tied directly to the integrity of your brain tissue. And of course we also know this because chemicals can change who you are and your personality. So you can turn a multi-tasker into a focuser with Adderall or vice versa with cocaine. So the first answer is yes, there are physical brain differences between multi-taskers and single focus individuals.
And the general story comes down to differences in the frontal lobe, so this is the part of your brain that's behind your forehead. This is essentially the thing that sets us apart from our nearest neighbors in the animal kingdom: we have a lot more frontal lobe than they do. And one of the jobs of the frontal lobe is sort of acting like the CEO of the company. It's about executive control and figuring out where to go next and what to do. It decides what it's going to do next and it locks down on that task. That's a properly functioning frontal lobe.
Some people with, for example attention deficit disorder, can pick a task and lock down on it, but the lock doesn't stay locked for very long and they flit off and then they lock down onto another task. And then they're off and onto another one. And so the key is, depending on the function of your frontal lobe, that tells how long you're going to be able to stick with one thing before flitting off of it.
And it turns out there is no sort of right answer about how long you should stay on a task because at the other end of the spectrum, there are problems where people can't get off of a task. This is known as perseveration. And it's one of the hallmark characteristics in schizophrenia is that somebody will choose a way of doing some task, for example, and won't change that, even in the face of all the data in the world telling them they should change their approach.
So in general, this is one of the ways that Mother Nature provides a lot of individual differences and then we get a very rich society out of that because some can people stay locked down for a long time, some people flit from task to task. But that essentially is the brain difference between multi-taskers and focusers.
Tom Weber: This sounds like you're getting close to the whole 'all this technology is going to reduce, and is reducing, our attention span' thing. It sounds like maybe there's a correlation between what you just said and that.
Eagleman: Well that may be true but for a slightly different reason which is that we just have so many more entertainment options now than any of our ancestors did. So it's not surprising that it's difficult for a kid to sit down with a 700-page book and stick with that, it's because there are so many things pulling at his or her sleeve for attention at the same time. Whereas in previous generations or centuries there just weren't that many options of other things to do.
I do think that one of the currencies for the next generation will be the capacity to pay attention for a sustained period of time. Those are gonna be the kids who turn out to be the winners.