A healthy brain can quickly switch its focus from large shapes to individual parts that make up a bigger picture — but for some people, this is a very jarring, effortful task.

This skill is called cognitive flexibility, and it is involved in virtually every complex behavior we undertake — from mental arithmetic to driving a car, according to Assistant Professor of Psychology John Medaglia.

“How fast people can make that transition – from the global to the local – is the switch cost, and that’s our index of flexibility,” he says.

Research from Medaglia and his colleagues at the University of Pennsylvania shows that the extent to which brain signals “stick” to white matter networks — or the brain’s highway system — is associated with cognitive flexibility. This suggests that some brains are at a natural advantage to meet switching demands.

They also validate a new method for measuring cognitive flexibility and open a new door for better understanding neurological disorders.

The study, Medaglia says, provides a “big picture” of cognitive flexibility, which is essential for future research.

“When thinking about how flexible someone’s brain is, or treating someone who is suffering, we now have a new way to answer, ‘Where do I need them to go? What kind of brain do we want to have?’ Without a measure for that, you don’t know what to do next,” he says. “This study opened a new door.”