She [Winifred Gallagher, author of Rapt: Attention and the Focused Life] recommends starting your work day concentrating on your most important task for 90 minutes. At that point your prefrontal cortex probably needs a rest, and you can answer e-mail, return phone calls and sip caffeine (which does help attention) before focusing again. But until that first break, don’t get distracted by anything else, because it can take the brain 20 minutes to do the equivalent of rebooting after an interruption. (For more advice, go to nytimes.com/tierneylab.)
“Multitasking is a myth,” Ms. Gallagher said. “You cannot do two things at once. The mechanism of attention is selection: it’s either this or it’s that.” She points to calculations that the typical person’s brain can process 173 billion bits of information over the course of a lifetime.
“People don’t understand that attention is a finite resource, like money,” she said. “Do you want to invest your cognitive cash on endless Twittering or Net surfing or couch potatoing? You’re constantly making choices, and your choices determine your experience, just as William James said.”
Gallagher says in a follow-up answer (to "Sarah") that "Like dieting, getting control of your craving for novel information requires rationing and self-control."
Now, I know this. You know this. So does Paul Silvia, the author of How to Write a Lot, who recommends the same method.
So why is it so hard to follow through, except by actually turning off the internet connection? But Gallagher has inspired me. I'm going to pull my funds from the investment bank of Facebook and put it under the mattress known as Word.