Cutting edge brain research on letting your mind wander—and when and why it's good for you.
Research has revealed that our brains are inherently noisy. A number of brain regions connected in what's dubbed the Default Mode Network (DMN) are always grinding away, engaged in a number of different involuntary activities that neuroscientists collectively call mindwandering: from daydreaming and self-chatter to ruminating about the past and worrying about the future. Not only does all of this inner commotion tug our attention away from the present moment, but it can dampen the quality of our experience, lowering our mood and potentially contributing to anxiety and depression. Yet, there's method to this apparent madness.

Mindwandering is our brain's way of developing our sense of self, trying to sort out what others are thinking, and searching for associations to help us interpret what's happening in our lives. It can be both positive and negative. On one...