Brain Can Only Pay Attention for 40 Minutes

I've known for years that my attention span in my graduate math classes has an upper limit of 45 minutes (probably a little less since the lecture usually doesn't start exactly on time). In situations where I don't have to pay attention continuously, I know my attention drifts in and out much more frequently than every 40 minutes or so, but if I already pretty much know what's going on, it doesn't matter much. I think the findings reported in this clip are significant in situations in which very careful attention to every detail is very important -- trying to follow a math proof, airport security, ...

clipped from www.sciencedaily.com 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. Distractions can break anyone's concentration, but new research shows what happens in your brain can, too. The phenomenon is such that the more you look, the less you see transcranial Doppler sonography (TDS). The device measures blood flow velocity in the brain researchers saw a decrease in blood-flow velocity over time, and, therefore, a decrease in attention Warm believes the study results can be helpful for the military, security workers, air traffic controllers and many others