Have you ever tried to solve a problem but couldn't find the answer? Then, once you stop trying and move on to something else, the answer comes with ease.
Now a psychology professor examines how these moments of insight occur while we're daydreaming. Psychologist Kalina Christoff from the University of British Columbia notes that many times, as you're falling asleep or staring off into space, you come up with the answer to a problem that's been vexing you. It's that phenomenon which interests her, but she says it's hard to study something that happens so spontaneously.
So, Christoff had to devise a way of getting people to not pay attention. To do that, she asked study subjects to perform the routine task of touching a computer screen every time they saw a number appear. Then she would stop subjects about once a minute - not so much that they would not be distracted, but enough to collect observations of when their minds were wandering.
"So what that allowed us to do is compare directly mind wandering versus thinking about the task and see what happens in the brain when you mind wander," Christoff says.
As they were being tested, Christoff's subjects were lying inside of a brain scanner. The machine is able to see what parts of the brain become more active as a person concentrates or moves.
Christoff says she saw several things happening as people's minds started to wander from the repetitive task. First, the "default network" became active. Those are the parts of the brain that get busy as we do simple tasks, like watching TV or stirring a cooking pot. Christoff says she expected to see these parts of the brain engaged. But she also saw other parts of the brain in action.
"We also saw the 'executive network,' the part of the brain that helps you solve very difficult problems and helps you make executive decisions also activated when people [were] mind wandering," Christoff says. "When people mind wander, very far from the brain becoming blank, it in fact becomes really active, and an expansive number of regions become quite active when your mind is wandering."
Christoff says usually, these two systems of the brain do not act at the same time. She says this tells her something about what's happening as we become preoccupied with a simple task.
"Even though you might not be working in a particularly focused way on any one problem, you do have at your disposal a number of different systems of the brain to work that problem," Christoff says. "You have an expanded range of resources available to deal with an issue that you might be mind wandering about."
Christoff says she'd like to do further research on how people can harness the power of the wandering mind and use it as a tool to help solve difficult problems.
Her research is published in the Proceedings of the National Academy of Sciences.