At New Yorker, "HOW TODAY'S COMPUTERS WEAKEN OUR BRAIN" makes some good points. First of all, humans, though they claim to be good at multi-tasking, are terrible at it.

[Humans are] not very good at achieving extreme states of concentration through sustained attention. It takes great training and effort to maintain attention on one object—in what Buddhists call concentration meditation—because the brain is highly susceptible to both voluntary and involuntary demands on its attention. Second, the brain is not good at conscious multitasking, or trying to pay active attention to more than one thing at once.

I am living proof of this struggle to focus.  When I am writing anything serious, I cloister myself in a room with phone off, door closed, no music.  That's how it must be if I want to write something I'll be proud of.   I can write in bad environments, but the product is often merely passable, not something excellent. The article then makes a strong argument that modern computers mostly exacerbate this problem we have with focusing:

[T]oday’s computers feature programming and writing tools more powerful than anything available in the twentieth century. But, in a different way, each of these tasks would be much harder: on a modern machine, each man would face a more challenging battle with distraction. Kafka might start writing his book and then, like most lawyers, realize he’d better check e-mail; so much for “Das Urteil.” Kerouac might get caught in his Twitter feed, or start blogging about his road trip. Wozniak might have corrected an erroneous Wikipedia entry in the midst of working on Breakout, and wrecked the collaboration that later became Apple.

Kafka, Kerouac, and Wozniak had one advantage over us: they worked on machines that did not readily do more than one thing at a time, easily yielding to our conflicting desires. And, while distraction was surely available—say, by reading the newspaper, or chatting with friends—there was a crucial difference. Today’s machines don’t just allow distraction; they promote it. The Web calls us constantly, like a carnival barker, and the machines, instead of keeping us on task, make it easy to get drawn in—and even add their own distractions to the mix. In short: we have built a generation of “distraction machines” that make great feats of concentrated effort harder instead of easier.

It’s time to create more tools that help us with what our brains are bad at, such as staying on task. They should help us achieve states of extreme concentration and focus, not aid in distraction. We need a new generation of technologies that function more like Kerouac’s scroll or Kafka’s typewriter.