Working memory capacity and the wandering mind

Studies have demonstrated that an individual's mind drifts off to unrelated thoughts regardless of what they are doing half of the time and chances are you will not read this entire article without thinking about something else. According to a study published March 14 in the journal Psychological Science, a person's working memory capacity - a sort of mental workspace that enables individuals to juggle several thoughts simultaneously - is associated with the tendency of their mind to drift to other thoughts during a routine assignment. For example, you arrive home and your neighbor greets you by your car in order to schedule a lunch date, on your way to add it to your calendar, you stop to turn on the lights, add bread to your grocery list, and feed the dog. Working memory is the capacity that enables you to retain the lunch information through those unrelated tasks. The study was conducted by Daniel Levinson and Richard Davidson at the University of Wisconsin-Madison and Jonathan Smallwood at the Max Planck Institute for Human Cognitive and Brain Science. Levinson, lead author of the study, is a graduate student with Davidson, a professor of psychology and psychiatry, in the Center for Investigating Healthy Minds at the UW-Madison Waisman Center. In order to compare a person's tendency to drift off, a group of volunteers were asked to perform one of two simple tasks. The first task required the volunteer to press a button in response to the appearance of a certain letter on a screen, while the second task involved simply tapping in time with one's breath. Smallwood said: "We intentionally use tasks that will never use all of their attention, and then we ask, how do people use their idle resources?" Occasionally, the researchers asked the volunteers if their minds were focused on the task or if their minds were wandering. The researchers then measured each participant's working memory capacity, and scored their ability to retain a series of letters given to them interspersed with simple math questions. According to Levinson, there was an apparent correlation in both tasks. "People with higher working memory capacity reported more mind wandering during these simple tasks," even though their performance on the test was not compromised. The study result is the first positive association discovered between mind wandering and working memory. This finding indicates that working memory may allow off-topic thoughts. Smallwood explains: "What this study seems to suggest is that, when circumstances for the task aren't very difficult, people who have additional working memory resources deploy them to think about things other than what they're doing." The researchers discovered that the association between mind wandering and working memory vanished when volunteers were given a similar simple task that was filled with sensory distractors (such as lots of other similarly shaped letters). Levinson said: "Giving your full attention to your perceptual experience actually equalized people, as though it cut off mind wandering at the pass." In earlier studies, working memory capacity has been associated with general measures of intelligence, such as IQ score and reading comprehension. The study highlights the importance in everyday situations and offers an insight into the omnipresent, yet poorly understood, world of inner driven thoughts. Smallwood, explained: "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." According to the researchers, although working memory can help an individual stay focused, if the mind starts to drift, those resources get misdirected and the individual can lose track of their goal. Several people have experienced the sudden realization that they have turned many pages in a book without taking in any of the words, or arriving at home with no recollection of the actual trip to get there. Levinson explained: "It's almost like your attention was so absorbed in the mind wandering that there wasn't any left over to remember your goal to read." According to Levinson, where an individual's mind drifts may be a signal of underlying priorities (whether conscious or not) being held in the individuals working memory. However, this does not mean that those with high working memory capacity are doomed to a wandering mind. Levinson explains that working memory is a resource and it is all about how an individual uses it. "If your priority is to keep attention on task, you can use working memory to do that, too." Levinson is currently investigating how wandering thoughts are affected by attentional training to increase working memory, in order to get a clearer picture of the association and how it can be controlled. Levinson said: "Mind wandering isn't free - it takes resources. You get to decide how you want to use your resources." The study received funding by the Fetzer Institute, the National Institutes of Health, and the Roke Foundation.