What effect does continuous divided attention have on the brain? The first point is that, as with most forms of greed, multi tasking is self defeating. Psychologist who have studied the phenomenon in detail conclude: multitasking may seem more efficient on the surface but may actually take more time in the end. And neuroscientists using brain scans of multitasking came to and even more definite conclusion. Performing two tasks one after the other was faster than performing the same two tasks almost simultaneously. It was the pre frontal cortex that processed the multitasking and it turned out to be unable to concentrate on more than one task at a time.
Of course these discoveries will deter no one, least of all me. I used to read a book to the end before beginning another but increasingly, I start new books without finishing the old ones - so I have more and more books with strips of newspapers sticking out of them.
And constantly switching attention may have long term effects on the brain. Neuroscientist have discovered that, for people in the age range between 35-39 years, electronic interruptions have little effect on the concentration on cognitive tasks, whereas for those between 18-21 years interruption caused a mark deterioration in performance. The suspicion is that, for the distracted generation, the constant need to process interruptions prevents the pre frontal cortex from developing fully. This is possible because the pre frontal cortex, which can be thought of as the brain's manager, the ego, is the last part of the brain to mature and is fully formed only after adolescent - one reason why adolescents are often id-controlled demanding, impulsive, ungrateful and angry. So the crucial executive controller is not only distracted by interruptions and hyper links but may be prevented from developing properly. Chronic distractions weakens the pre frontal cortex - and with the opposite effect, long term meditation strengthens it.
However it is becoming impossible to avoid distraction. The new built environment is a text sprinkled with physical hyperlinks. The very concepts of separation and boundaries are becoming obsolete. Airports, railway stations, office blocks, hotels and hospitals have become mini cities with large, bright, high ceilinged, open - plan areas offering a distracting range of products and services. And the cities themselves have become increasingly porous, with living, working, shopping, eating and drinking areas leaking into each other. New city developments such as London Dock Lands are designed according to this principle, known to architects as caves and commons, which blurs the distinctions between inside and outside, work and leisure, public and private.
