Ever driven a long distance and been shocked to arrive at your destination with no memory of the trip itself? Turns out a wandering mind is nothing to worry about, and that daydreaming may, in fact, be linked to a brain mechanism that spares you from focusing on the daily grind.
A new study sheds further light on the little-known workings of the brain’s default mode network (DMN), a group of interconnected brain regions believed to be responsible for daydreaming and mind wandering. Its results provide compelling evidence that, in addition to helping spur “eureka” moments in well-known daydreamers from Einstein to Archimedes, the DMN plays an integral role in our ability to perform tasks on autopilot, allowing us to guess likely outcomes ahead of time, and thus devote fewer mental resources to mundane tasks.
The study challenged the idea that the brain’s “default mode” is passive. To examine how this mode directly impacts brain activity, researchers monitored 28 volunteers’ brains as they sat in an MRI scanner while completing a novel task, and continued to track activity as the task became routine. Specifically, participants had to figure out how to match sets of cards with no instructions provided; for instance, the cards might match based on numbers, shapes or colors. Once participants understood the rules, they began matching cards almost automatically; this behavioral shift aligned with a shift in their brain activity from the Dorsal Attention Network, which helps select and process salient visual information, to the DMN.
Additionally, those with stronger interactions between the DMN and hippocampus (the region responsible for memory) performed more accurately, suggesting the DMN actively engages with memory to allow us to complete routine tasks while “tuned out.” Senior author Emmanuel Stamakis concluded: “We showed that the DMN is not a bystander in these tasks: it plays an integral role in helping us perform them.”
Nevertheless, neuroscientists still know very little about how this network operates and what realms of cognition it controls. Several prior studies reveal tantalizing details about the DMN’s role in creative thought.
Recently, researchers found evidence linking daydream frequency with intelligence and creativity. Participants completed MRI scans and cognitive ability tests, as well as a “mind wandering questionnaire” measuring their typical daydream frequency. Those who reported daydreaming the most had the highest cognitive test performance; they also showed stronger interactions between the DMN and frontoparietal control network (which controls working memory and the ability to adapt to situations).
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