Now we know that there are developmental differences in task switching. That people, as they get older, they get better at switching between tasks. This has been handled in developmental literature where people have actually looked at what happens when children begin to do tasks in which they switch. So, for example, they could do a task, in which they have to look at a filled dot. Or a striped dot and then decide if it's on the left or the right of a screen. So, on one condition they might have a filled dot. And the filled dot indicates a left button response. They have two buttons. They get a filled dot. They have to press the left button when they get a filled dot. It doesn't matter where the dot appears. Notice that this task is easier when this dot is filled and it's on the left because the filling of the dot, and the side of the dot, indicate the same response. Harder when the dot is on the opposite side. So the dot is on the right and it's filled but I have to press the left button. Then I have to ignore the side, and tend to what's inside the dot. A group of researchers looked at this and then they asked, what happens when we switch between tasks? When we asked them to do right, left and right, but then we have different dots, right, dots that are left or right responses. And in fact children will slow down. They'll show a slowing effect when they have to switch between the dots and that slowing effect gets smaller into adulthood. So adults will not show as big of a slowing effect when they're switching between these different types of dots. Suggesting again, that the ability to switch between tasks becomes more difficult for adults. Subsequent studies looked at, how switching involved brain mechanisms. So in one seminal study, a group of researchers from UC Berkeley ask children to go into an FMRI scanner and look at these different types of stimuli and perform a task switch, in which they switched between tasks or they just did one single task, for every stimulus. Must like Driscoll did with addition and subtraction. Or the other study did with the dots, that were filled or not filled. What they found was that there were differences between children, and adolescents, and adults in the supplementary motor area. The supplementary motor area is an area involved in motor planning. And it's also an area that is often active when there are errors and those are detected. The children showed increased activity in the supplementary motor area relative to adults and adolescents. But interestingly when they, researchers looked at an activity in the dorsal lateral prefrontal cortex. They found that children, adolescents and adults all differed in the activity in the dorsal lateral prefrontal cortex, suggesting that some areas show differences across age. And other areas show differences only in childhood. So, this section and the results from tasks which in types of experiments with children, has shown that in fact across development, there's an improvement, in the ability to do task switching. And that this improvement involves different brain areas. And of course, at the heart of it is the dorsolateral prefrontal cortex. An area that's been found to be active for executive function types of tasks and differentiates between children, adolescents and adults
