When you don’t give its human anything to do, brain areas related to processing emotions, recalling memory, and thinking about what’s to come become quietly active. These self-referential streams of thought are so pervasive that in a formative paper Marcus Raichle, a Washington University neurologist who helped found the field, declared it to be the “the default mode of brain function,” and the constellation of brain areas that carry it out are the default mode network, or DMN. Because when given nothing else to do, the brain defaults to thinking about the person it’s embedded in. Since then, the DMN has been implicated in everything from depression to creativity. People who daydream more tend to have a more active DMN; relatedly, dreaming itself appears to be an amplified version of mind-wandering.
Whether or not your default activity is helpful or harmful depends on where your mind automatically tends to go, says Scott Barry Kaufman, the scientific director at the Imagination Institute at the University of Pennsylvania. In the same way that your tongue defaults to probing a cut on the roof of your mouth, the brain is attracted to unresolved issues. “People differ drastically regarding if their default mode network content is creative or ruminative,” he says.
In a way, the DMN is like a scout, ranging about for prospective futures. To Kaufman, the default mode has a “prospective bias”: It’s seeking out big-picture strategies for what could be. Depending on the person, their history, and their biological dispositions, that prospection could tilt toward worrying or hoping. As psychologists have contended for decades, daydreaming itself has at least three different flavors: positive constructive daydreaming, which has lots of playful, wishful imagery and plan-making thoughts; guilty-dysphoric daydreaming, which has lots of anguish and obsessive fantasies; and poor attentional control, where it’s hard to concentrate on anything. “Prospection can lead to suffering if it hinders executive attention, the ability to have awe, attention to the present moment,” he says, emphasizing that, as with so many others ways that our minds get into trouble, the problem is rigidity; research indicates that a disturbed DMN is a mechanism in depression. “Our greatest source of suffering isn’t the default mode,” Kaufman says, “but when we get stuck in the default mode.”
The key is what brain science people call “cognitive flexibility”: being able to more freely choose your mental habits, and have greater agency in your cognitive phenomena. CBT and even hypnosis are options for taming an unruly DMN, as is the fashionable yet ancient practice of meditation. Study after study indicates that meditation reduces activity in the DMN. Judson Brewer, psychiatrist and director of research at the UMass Medical School Center for Mindfulness founded by Kabat-Zinn, has found that extended meditation practice reforms the DMN, so that the default mode itself shifts: The resting state of the brain becomes more like the meditative state, producing “a more present-centered default mode.” So maybe that’s what all that advice to live in the present moment is getting at: If you can invest more attention in the sensory world than in your narrative overlaying it, you might identify the former, rather than the latter, to be what’s true.
– Drake Baer
Read more: Is the Default Mode of the Brain to Suffer?
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