Be a daydream believer
Odds are, you're not going to make it all the way through this article without thinking about something else. Now a new study investigating the mental processes underlying a wandering mind reports a role for ‘working memory’, a sort of a mental workspace that allows you to juggle multiple thoughts simultaneously. Imagine you see your neighbour upon arriving home one day and schedule a lunch date. On your way to add it to your calendar, you stop to turn off the drippy tap, feed the cat, and add milk to your shopping list. The capacity that allows you to retain the lunch information through those unrelated tasks is working memory.
Using idle resources
Researchers from the University of Wisconsin-Madison and the Max Planck Institute for Human Cognitive and Brain Science, report that a person’s working memory capacity relates to the tendency of their mind to wander during a routine assignment. The team asked volunteers to perform one of two simple tasks - either pressing a button in response to the appearance of a certain letter on a screen, or simply tapping in time with one's breath - and compared people's propensity to drift off.
"We intentionally used tasks that would never use all of their attention," lead researcher Jonathan Smallwood explains, "and then we asked, how do people use their idle resources?" Throughout the tasks, the researchers checked in periodically with the participants to ask if their minds were on task or wandering. At the end, they measured each participant's working memory capacity, scored by their ability to remember a series of letters given to them interspersed with easy math questions.
In both tasks, there was a clear correlation. "People with higher working memory capacity reported more mind wandering during these simple tasks," says Smallwood, though their performance on the test was not compromised. The result is the first positive correlation found between working memory and mind wandering and suggests that working memory may actually enable off-topic thoughts.
Working memory capacity has previously been correlated with general measures of intelligence, such as reading comprehension and IQ score. The current study underscores how important it is in everyday situations and offers a window into the ubiquitous - but not well-understood - realm of internally driven thoughts.