By BENEDICT CAREY

Even the most fabulous, high-flying lives hit pockets of dead air. Movie stars get marooned in lines to renew their driver’s licenses. Prime ministers sit with frozen smiles through interminable state events. Living-large rappers endure empty afternoons, staring idly out the window. Wondering: When does the mail come, exactly?
Scientists know plenty about boredom, too, though more as a result of poring through thickets of meaningless data than from studying the mental state itself.
Some experts say that people tune things out for good reasons, and that over time boredom becomes a tool for sorting information . Research suggests that falling into a trance allows the brain to recast the outside world in ways that can be productive and creative at least as often as they are disruptive.
Psychologists have most often studied boredom using a questionnaire that asks people to rate how closely a list of sentences applies to them: “Time always seems to be passing too slowly,” for instance.
High scores in these tests tend to correlate with high scores on measures of depression and impulsivity. But it is not clear which comes first - proneness to boredom, or the mood and behavior problems. “It’s the difference between the sort of person who can look at a pool of mud and find something interesting, and someone who has a hard time getting absorbed in anything,” said Stephen J. Vodanovich, a psychologist at University of West Florida in Pensacola.
Boredom as a temporary state is another matter, and in part reflects the obvious: The brain has concluded there is nothing new or useful it can learn from an environment . But it is far from a passive neural shrug. Neuroscientists have found that the brain is highly active when disengaged, consuming only about 5 percent less energy in its resting “default state” than when involved in routine tasks, according to Dr. Mark Mintun, a professor of radiology at Washington University in St. Louis.
That slight reduction can make a big difference in terms of time perception. The seconds usually seem to pass more slowly when the brain is idling than when it is absorbed.
In the past few years, a team of Canadian doctors had the courage to examine the fog of boredom . While attending lectures on dementia, the doctors, Kenneth Rockwood, David B. Hogan and Christopher J. Patterson, kept track of the number of attendees who fell asleep during the talks.
They found that in an hourlong lecture attended by about 100 doctors, an average of 16 audience members nodded off into a nap. The investigators analyzed the presentations themselves and found that a monotonous tone was most strongly associated with “nod-off episodes per lecture,” followed by the sight of a tweed jacket on the lecturer.
Dr. Rockwood said when the material presented is familiar, as a lot of it was, then performance is everything. “Really, what it comes down to,” he said, “is that if you have some guy up there droning on, it drives people crazy.”
Dr. Rockwood and his co-authors have followed up with two more related reports and attribute the inspiration for the continuing project to Dr. Patterson. Early on in one of those first dementia lectures, he fell into a deep sleep.