Our minds are built to wander, according to a new study that argues we have a network of brain regions dedicated to meandering thoughts that turns off and on depending on how focused we need to be to complete different tasks. Previous studies have shown that this “default” network, which is composed of at least seven separate brain regions, kicks in anytime we are at rest—say, passively taking in a TV show or a sunset. But the function of letting our gray matter go gallivanting has been unclear. Now Malia F. Mason of Harvard Medical School and her colleagues have found that dull or unchallenging tasks switch on the default network. They scanned the brains of several subjects while their memory of short sequences of letters was being evaluated. When tested on a familiar set of letters that the subjects had been trained on for days—boring!—their daydreaming networks switched into overdrive. But when they had to focus on sorting out new combinations of letters, the networks fell quiet. This pattern matched each person’s own reports of when his or her mind wandered from the tasks. “We’re constantly doing things that are pretty mundane,” Mason says. She points out that daydreaming is not always frivolous: “Most people say they’re planning or thinking about the future, and that’s extremely adaptive.”
Previous studies have shown that this “default” network, which is composed of at least seven separate brain regions, kicks in anytime we are at rest—say, passively taking in a TV show or a sunset. But the function of letting our gray matter go gallivanting has been unclear.
Now Malia F. Mason of Harvard Medical School and her colleagues have found that dull or unchallenging tasks switch on the default network. They scanned the brains of several subjects while their memory of short sequences of letters was being evaluated. When tested on a familiar set of letters that the subjects had been trained on for days—boring!—their daydreaming networks switched into overdrive. But when they had to focus on sorting out new combinations of letters, the networks fell quiet. This pattern matched each person’s own reports of when his or her mind wandered from the tasks.
“We’re constantly doing things that are pretty mundane,” Mason says. She points out that daydreaming is not always frivolous: “Most people say they’re planning or thinking about the future, and that’s extremely adaptive.”
