From
Science Daily:
Psychologists are finding out that even when people try to focus on a task they tend to lose concentration within 40 minutes, and sometimes as little as 10 minutes. The studies are based on a new technique, called transcranial Doppler sonography, that uses ultrasound to monitor blood flow velocity in the brain. The technique could be turned into a warning system for workers who perform critical tasks -- such as pilots or air traffic controllers -- or even for drivers.
I'd love to see the results if they did this kind of scan on long-time meditators. My hunch, naturally, is that they'd be able to pay attention longer.
I think that is a function of environment and personality more than anything else. In a place with no distractions, or when people do not come over and I have loud rhythmic music blasting so I have no other sensory issues, I can hands-down code for about three hours -- just long enough for me to get really thirsty.
But on the flip side, when there are often people wandering by or IMs or loud conference calls, I can barely maintain five minutes. Distractions.. well, they distract me. And when programming you really need 10-15mins to get into the zone, so constant interruptions cause failure on my part. Once in the zone I can stay in there easily, until...