Most people spend anywhere between one-third to half of their waking hours daydreaming. Although we are often told to stop dreaming or zoning out of the present moment, it may not be a total waste of time. In fact, there could even be benefits to having your head in the clouds.
Yale University emeritus psychology professor Jerome L. Singer — author of “The Inner World of Daydreaming,” published in the 1960s — defined daydreaming as “a shift away from some primary physical or mental task, toward an unfolding sequence of private responses.” He distinguished positive-constructive daydreams from dysphoric, or negative, ones. Positive daydreaming is guided by a sense of playfulness and an optimistic outlook. Dysphoric fantasies revolve around themes such as anxiety, aggression, and failure. Most people experience both kinds.
Other definitions have been put forth to explain daydreaming. The cognitive psychologist Michael Kane, of the University of North Carolina at Greensboro, broadly defines daydreams as “any thoughts that are unrelated to one’s ongoing activities,” or, more simply, “off-task thinking.”
A single daydream usually lasts only a few minutes. And some people have only a few every day, while others are constantly lost in thought. Children and young people tend to daydream more than adults. Some daydreams are clear in our minds, replaying like a movie, while others are more vague. They typically reflect our hopes, fears, and desires, revealing a great deal about our intricate inner world.
We are often unaware that our thoughts are roaming. We slip into daydreaming easily and with little effort. Scientists have long assumed that the brain was resting and not doing much at all. Yet researchers are discovering that a wandering mind is also a very active one.
A Web Of Connection
In only the last two decades, neuroscientists have pinpointed several parts of the brain that are essential to daydreaming. Known as the “default mode network,” these interconnected regions are active when our attention drifts away from the outside world to our inner stream of consciousness. The network links many parts of the brain, including the medial prefrontal cortex, the posterior cingulate cortex — both of which are involved in self-reflection — and the parietal cortex. It is active when we recall past experiences, ponder future events, or imagine what others are thinking or feeling.
Cognitive neuroscientists have been able to examine the brain in the middle of daydreaming. Kalina Christoff and colleagues used functional MRI to link mind-wandering to the default network. Their participants for the study were given a tedious task — they were shown numbers 0 to 9 and had to press a button whenever any number except 3 appeared. When they inevitably lost their focus, Christoff’s team of researchers could see the exact moment when their attention tapered off. Just before an error, activity in the default network of the brain soared, and the executive system was also recruited. Activity was greatest when people did not notice that their thoughts had wandered, suggesting that elaborate daydreams are more absorbing and engage the brain more fully.
Daydreaming is still not well understood, however. Brain scans may show heightened activity, but they cannot distinguish whether it was triggered internally or externally. The neurologist Marcus Raichle, of Washington University in St. Louis, has written a series of papers on the resting brain, which is actually never at rest. Why the brain remains so active during the “resting state” is still a mystery.