What happens on a neurological level while our minds wander is actually pretty fascinating. According to the Neuroenergetic Theory proposed by Killeen et al., our attention starts to lag after just twelve seconds of effort because our neurons run out of fuel. Neurons first look to glial cells for lactate, a readily used sugar, and if they can’t find it, they look for glycogen, which is stored up at night when we sleep.

If our neurons can’t find the lactate or glycogen needed to focus, they get exhausted––enabling other parts of the brain to call for attention. That’s when the mind starts to wander.

“These functions that all come from within — like imagination and mind-wandering — have been shown to be really important contributors to creativity.”

This happens to us all from time to time, especially when we don’t get enough rest or the right nutrition. But it can happen more frequently to those of us who just have trouble concentrating, or find ourselves zoning out more than we should.

So what’s the result for our daily lives? When is it okay to let our minds wander, and when should we try to resist? The answer may surprise you.

Performance

The majority of literature on the topic suggests that mind-wandering typically occurs at a significant cost to performance. Mind-wandering–related deficits in performance have been observed in many contexts, most notably reading, tests of sustained attention, and tests of aptitude. Mind-wandering has been shown to negatively impact reading comprehension and model building, impair the ability to withhold automatised responses, and disrupt performance on tests of working memory and intelligence.

The researchers found that individuals’ minds wandered less when they were doing what they were good at, but wandered more when they were doing something that required more effort.

In reading tasks, for instance, mind wandering frequency is directly related to poor reading comprehension, not to mention how much of the material read is actually remembered afterward. Measuring this relationship usually involves tests of reading comprehension as well as direct measurement of eye gaze and reading time.

By any measure used, children prone to mind wandering perform much more poorly and may even lead to their being diagnosed with an attention disorder.

The same relationship applies to other cognitive tasks measuring attention span, selective attention, and problem-solving.

Another context in which mind-wandering can be problematic is when we are trying to complete a task or activity that we know we’re not good at. From a rewards perspective, it’s easy to see why we are able to concentrate on a task we’re good at. But when we’re feeling challenged or overwhelmed, mind-wandering can seriously deter us from accomplishing our goals.

In a 2011 study, 165 undergraduate students at Zhejiang Normal University were probed for mind-wandering six times a day over the course of three days, and completed a questionnaire about their immediate conscious experience each time they received the probe signal. The questionnaire was designed to probe four aspects of mind wandering in daily life: content, context, reasons, and meta-awareness.

The researchers found that individuals’ minds wandered less when they were doing what they were good at, but wandered more when they were doing something that required more effort.

These findings are consistent with the research team’s previous studies: minds wandered less when participants were concentrated or felt competent, while the decreased demand of a task increased its frequency.

Happiness

Time and time again, researchers have found that life satisfaction correlates with academic achievement, ability to focus, and overall career success.

In a 2011 TED talk, Matt Killingsworth discusses an app, Track Your Happiness, which allows people to chart their feelings on a moment-by-moment basis. As they go about their day, app users get random pings, asking them to share their current activity and note their mood. When Killingsworth gave this talk, the app had collected data from more than 15,000 people in 80 countries, representing a wide range of ages, education levels, and occupations.

In this talk, Killingsworth reveals a very surprising finding: that mind-wandering appears to factor heavily into this happiness equation.

Killingsworth found that mind-wandering appears to be correlated with unhappiness. When people were mind-wandering, they reported feeling happy only 56% of the time. Meanwhile, when they were focused on the present moment, they reported feeling happy 66% of the time. This effect was true regardless of the activity the person was doing — be it waiting in line or eating a tasty meal.

Memory

Mind-wandering might make us feel less content, but it could also have a functional purpose.

A recent study published in the journal Psychological Science suggests that mind-wandering might be a sign of a high capacity working memory — in other words, the ability to think about multiple things at once. Researchers asked study participants to press a button and, as they went, checked in to see if their minds were wandering. After the task was complete, researchers gave participants a measure of their working memory. Interestingly, those who were found to be frequent mind-wanderers during the first task showed a greater capacity of working memory.

Interestingly, those who were found to be frequent mind-wanderers during the first task showed a greater capacity of working memory.

Researcher Jonathan Smallwood of the Max Planck Institute for Human Cognitive and Brain Science explains, “Our results suggest that the sorts of planning that people do quite often in daily life — when they’re on the bus, when they’re cycling to work, when they’re in the shower — are probably supported by working memory. Their brains are trying to allocate resources to the most pressing problems.”

Mind-wandering might also play a vital function in helping us form memories. New York University neuroscientist Arielle Tambini looked at memory consolidation in this study published in the journal Neuron in 2010.

Participants in the study were asked to look at pairs of images and, in between, were instructed to take a break to think about anything they wanted. Using fMRI, the researchers looked at the activity in the hippocampus cortical regions while they did both. The study showed that these two areas of the brain appear to work together — and that the greater the levels of brain activity in both areas, the stronger the subjects’ recall of the image pairing was.

Explains Lila Davichi, who oversaw the study, “Your brain is working for you when you’re resting, so rest is important for memory and cognitive function. This is something we don’t appreciate much, especially when today’s information technologies keep us working round-the-clock … Taking a coffee break after learning can actually help you retain that information you just learned.”

Creativity

Sometimes it’s spontaneous thought that awards us with our greatest ideas. A recent study published in the journal Psychological Science gives a clue as to why. A research team led by Benjamin Baird and Jonathan Schooler of the University of California at Santa Barbara asked participants to take “unusual uses” tests — brainstorming alternate ways to use an everyday object like a toothpick for two minutes (an ability also known as divergent thinking).

Study participants did two of these sessions, and then were given a 12-minute break, during which they were asked to rest, perform a demanding memory exercise or do a reaction time activity designed to maximise their mind-wandering. After the break, they did four more unusual uses tests — two of them repeats.

Research has even shown that on standardised tests, when students are allowed to mind-wander and make personal connections to their own lives, they perform better on exams

While all of the groups performed comparably on the two new unusual uses lists, the group that had performed the mind-wandering tasks performed 41% better then the other groups on the unusual uses lists they were repeating. “The implication is that mind-wandering was only helpful for problems that were already being mentally chewed on. It didn’t seem to lead to a general increase in creative problem-solving ability,” says Baird.

“When we see someone daydreaming, we have no idea what’s going on in their head,” he says. “These functions that all come from within — like imagination and mind-wandering — have been shown to be really important contributors to creativity.”

Research has even shown that on standardised tests, when students are allowed to mind-wander and make personal connections to their own lives, they perform better on exams, Kaufman says.

[Read more about creativity in Cultivating Creativity.]

Personal Goals

Scott Barry Kaufman, NYU psychology professor and author of Ungifted: Intelligence Redefined, says we need a new definition of intelligence–one that factors in our deepest dreams and desires.

“We all have goals and dreams in life–things we want to accomplish out there in the real world,” Kaufman tells The Huffington Post. “And while the kinds of skills that are measured on IQ tests are important … there are so many more characteristics that come into play in helping us to reach those dreams and goals in a long-term way.”

Our traditional standard of intelligence is lacking, Kaufman explains, and it can leave behind many people who don’t perform well on rote cognitive skill tests, but who may be highly adept when it comes to spontaneous cognition.

“We tend to think of smart people as those who learn really quickly and do well on IQ tests,” Kaufman says. “I felt like so many people were being judged as stupid too quickly entirely based on these scores … I wanted to look at what happened when we get these students really engaged in something that’s personally meaningful to them.”

Kaufmans’s Theory of Personal Intelligence, as outlined in Ungifted, explains intellect in broader terms, focusing on cognitive engagement and ability as applied to the pursuit of personal goals. The theory takes into account not only traditional markers of intelligence such as working memory and attention (controlled forms of cognition), but also spontaneous forms of cognition, including insight, intuition and the triggering of memories and stored information–types of intelligence often accessed through mind-wandering.

According to Kaufman’s theory, mind-wandering can play an important role in personal adaptation. He wrote in a recent Scientific American blog (based on a paper he co-authored with Rebecca L. McMillan, “Ode To Positive Constructive Daydreaming”) that mind-wandering can offer significant personal rewards:

These rewards include self- awareness, creative incubation, improvisation and evaluation, memory consolidation, autobiographical planning, goal driven thought, future planning, retrieval of deeply personal memories, reflective consideration of the meaning of events and experiences, simulating the perspective of another person, evaluating the implications of self and others’ emotional reactions, moral reasoning, and reflective compassion…

From this personal perspective, it is much easier to understand why people are drawn to mind wandering and willing to invest nearly 50 percent of their waking hours engaged in it.

Future Thinking

A lot of the thinking we do during mind-wandering tends to focus on future events.

Without realising it, we use mind-wandering to anticipate and plan out future goals and rehearse all the different ways those future goals can go wrong. Since mind-wandering usually happens during tedious tasks which don’t require that much mental activity, pondering future events may have an important evolutionary advantage, according to Canadian psychologist Romeo Vitelli.

Research shows that people with higher working memory capacities are more likely to mind-wander about the future than they are about the past, lending further credence to the benefits of future thinking.

Attentional Cycling and Dishabituation

Mind-wandering can support multi-tasking by allowing us to “cycle through” various problems we might be facing before we actually face them, thereby keeping them all fresh in our mind and making them easier to deal with as they arise. A wandering mind can also help us get through demanding tasks by affording a short mental vacation.

Spending too much time on a task can make us too tired to give our full attention to what we are working on, resulting in a psychological phenomenon called “habituation.” Brief periods of mind-wandering can make us return to the task feeling a little more refreshed, or “dishabituated,” in effect letting us recharge our mental batteries.