Until recently, scientists would have found little of interest in the purposeless, mind-wandering spaces between Mrazek’s conscious breakfast-making tasks — they were just the brain idling between meaningful activity.

But in the span of a few short years, they have instead come to view mental leisure as important, purposeful work — work that relies on a powerful and far-flung network of brain cells firing in unison.

Neuroscientists call it the “default mode network.” […]

That’s in sharp contrast to the pattern struck by the brain when hard at work: In this mode, introspection is suppressed while we attend to pressing business — we “lose ourselves” in work. As we do so, scientists see the default mode network go quiet and other networks come alive.

LA Times: An idle brain may be the self’s workshop

I’ve noted before that the bored brain uses more energy than an engaged brain (and that also boredom can be lethal). It seems clear that we also need enough idle time as well.