When your mind is wandering, your brain’s “default mode” network is active. Its discovery 20 years ago inspired a raft of research into networks of brain regions and how they interact with each other.

When I first heard the term "default mode network," I wondered if it had something to do with telephones or the internet. It doesn't. What it does have to do with is much more intriguing. The default ...

A neighbor once told me that he often dresses, ties his shoelaces, drags his toothbrush around, starts the car, drives down the parkway, and arrives at his office without much mental effort; this ...