Think you can't live without your PDA or phone because it makes your life more convenient, and your work easier?  Not so fast. 

Guess what?  Cognitive psychologists who study workers who are interrupted with pop-ups, email alerts, calandar reminders, and instant messaging, report that users of these kinds of technologies are suffering from distraction overload and continuous partial attention.   Their conclusion after much research - you risk never focusing on any thought or perception for long, as well as rarely being able to work straight through to completion on anything.    In fact, research at the University of California, found that the average worker spends only 11 minutes on any given project before being interrupted and it takes an average of 15 minutes for most workers to productively resume a challening task after they've been interrupted by something as small as an email alert.  But even with the virtues of the handheld, that many interruptions can impair higher cognitive functioning such as decision making. 

Why?  The delay reflects how long it takes to reactivate memories and refocus thinking resources.  Interruptions can also dereail brain processes that sort incoming signals, causing memory loss and decreased memory accuracy.  And the more brain power that the interruption demands, the more disruptive it will be to the task you're being pulled away from.  So cognitive scientists conclude that there is no such thing as multitasking with your crackberry because it is impossible to process information or use your frontal lobe as effectively, impeding concentration,  and creativity.  So think again when your boss tries to tell you how much more productive you will be with a Blackberry on your hip at the grocery store, dinner table, vacation beach or in the car.