The Lurking Power Behind Your Daydreams


By Katherine Peng

Despite my advocacy for the “use your brain or lose it” philosophy, I will admit to occasionally (alright, more than occasionally) enjoying the oh-so-satisfying pleasure of sitting back and not having to think about anything at all. But of course, our minds never shut off completely. Be it head-in-the-clouds on a subway train or walking down the street, we inevitably enter a self-obsessive stream of consciousness containing shopping lists, weekend plans, or who’s kicking the bucket on the next Game of Thrones.

Contrary to our brains being “at rest”, over half the equivalent energy of an active brain is being used to fuel these daydreams while our bodies are wakefully resting – leading some to dub this as our brain’s mysterious “dark energy”. While the name itself may sound ominous, can this baseline activity actually be dangerous? In 2010, a Harvard study developed an iPhone application that charted participants’ thoughts and happiness randomly throughout the day to reveal that people whose minds were wandering were less happy at the moment than those who were focused. Is it true then that the root of unhappiness stems from dwelling in our thoughts rather than enjoying the present moment?

Here is a philosophical question that may indeed have a biological answer. In 2001, Dr. Marcus Raichle noticed that there is a network of brain structures that is consistently activated when a participant is letting his/her mind wander in a functional MRI machine, but becomes deactivated when asked to perform a task. He coined this the “default mode network”. This DMN has since been indicated to play roles in creativity and planning, and reveals its significance in a study on autistic patients where permanently dampened DMNs prevent them from producing internal pictures of themselves and others.

However, overactivation of this network has also been implicated in multiple mood and mental disorders as well. In patients of major depressive disorder, dominance of the DMN over a task dominant network correlates with higher levels of depressive rumination. Many studies have also linked an overactive DMN to schizophrenia, hypothesizing it as the culprit of blurred boundaries between imagination and reality.

So how can we improve our mental well-being when the DMN is activated at the literal blink of an eye? It turns out that the answer is mindfulness. An imaging study at Yale has found that experienced meditation subjects had decreased DMN activity during meditation, one that was kept in check by co-activated brain regions associated with self-monitoring and cognitive control. Even more impressive was the ability of experienced meditaters to do this even when they were told to rest without meditation, indicating the development of a new and improved default mode network with the superior ability to suppress “me” thoughts.

And if that doesn’t make sitting still for extended periods of time sound at all appealing, there’s always the age-old method of… snapping out of it! We’ve heard it a million times, but it might help to just remind yourself to open your (mind’s) eyes and appreciate the beauty of what’s right there in front of you.