A couple of weeks ago in the journal Psychological Science, collaborators of mine from Nothumbria University published a study that looked at the reason why mind-wandering is associated with reduced processing of task relevant information. Using, EEG we measured the cortical response to events in a task. In this experiment we were especially interested in the brains response to distractor stimuli, because we wanted to assess whether people who mind wander are easily distracted. Our study showed the people who reported the most off task thoughts tended to show the smallest response to both the targets in the task and to the distracters. Thus while mind-wandering is associated with poor performance on task, this is independent of a process of external distraction. This result is important because it shows that the experience of mind wandering is not simply a state of poor attentional control, because the people who did the most mind wandering were also able to ignore the distracters in a sustained attention task. Rather than simply being a state of distraction, this study suggests that one reason why the mind neglects external information is because when it daydreams, the brain needs to filter out perceptual information, so as to allow it to concentrate on an internal train of thought. Failing to attend to perceptual information during idle moments is probably one important reason why we are able to concentrate on other more important personal goals, such as what to have on a dinner date or where to go on vacation. Rather than being a problem, being absent from the here and now when the conditions allow, may actually facilitate focus on the other problems that occupy our daily lives.
Mind-wandering is a product of spontaneous, internally generated thought