When you are just sitting and doing nothing, what is your brain doing? What happens when you are wandering around, looking at nature and "resting your brain?" Well, it turned out that your brain is very busy defining yourself as an individual being.
Article continues below
Until recently, scientists saw no interest in the mind-wandering spaces between consciously made tasks. They were just the brain idling between meaningful activity. But in the span of a few years, scientists came to view mental leisure as important work, a work that relies on a powerful network of brain cells firing in unison. Neuroscientists call that the "default mode network."
The brain regions that make up that network have long been recognized as active when people recall their pasts, project themselves into future scenarios, impute motives and feelings to other people, and weigh their personal values.
But when these structures work in unison, and scientists found that when we daydream they do just that, they function as our brain's "neutral" setting. Understanding that setting may one day help diagnose and treat psychiatric conditions as diverse as Alzheimer's disease, autism, depression and schizophrenia all of which disrupt operations in the default mode network.
Beyond that lies an even bigger promise. As neuroscientists study the idle brain, some believe they are exploring a central mystery in human psychology: where and how our concept of "self" is created, maintained, altered and renewed. After all, though our minds may wander when in this mode, they rarely wander far from ourselves.
That's in sharp contrast to the pattern struck by the brain when hard at work: In that mode introspection is suppressed while we attend to pressing business, in other words we "lose ourselves" in work. As we do so, scientists see the default mode network go quiet and other networks come alive.
Neuroscientists resisted discussions of "self" as too difficult for a long time. But now research on the default mode network helped to focus on our rich inner world and raises the prospect that our sense of self, our existence as a separate being, can be observed and measured.
People talk about "the self" and ask how it is created in the brain. The default mode network seems to be a key to unlocking that mystery: It captures many features of how we think of ourselves as the self. Neuroscientists suspect that the default mode network may speak volumes about our mental health, based on studies that suggest it is working slightly differently in people with depression, autism and other disorders. ■